Printable Solar Panels

Printable Solar Panels
Fasten your seatbelts. What you are about to hear is full of promise but potholed with hype: paintable, plasterable, printable solar panels, harvesting energy from the sun. Here's the quote on MIT's Technology Review (July/August 2004), "Breakthroughs in nanotech are making it possible to turn out cheap, flexible solar cells by the meter. Soon your cell phone may be powered by the sun." In this report, we will discuss the many issues brought up by this quote, both about technology evolution, business hype and nanotechnology's great promise. We also provide a school resource to help students think about where solar power can be used and where it's underkill. Nanotechnology helps solar power overcome the limits of expensive flat-panel semiconductor technology. Nano also can help improve cell efficiency. Ultimately, applications for such technology are an issue of cost and reliability.

PHOTOELECTRIC DREAMS

1876 - PHOTOELECTRIC DREAMS
William Grylls Adams, who, with his student, Richard Evans Day, discovered in 1876 that a solid material - selenium - produced electricity when exposed to light. Today, we refer to electricity produced directly from light as the photovoltaic effect.
When William Grylls Adams and his student, Richard Evans Day, discovered that an electrical current could be started in selenium solely by exposing it to light, they felt confident that they had discovered something completely new. Werner von Siemens, a contemporary whose reputation in the field of electricity ranked him alongside Thomas Edison, called the discovery "scientifically of the most far-reaching importance." This pioneering work portended quantum mechanics long before most chemists and physicist had accepted the reality of atoms. Although selenium solar cells failed to convert enough sunlight to power electrical equipment, they proved that a solid material could change light into electricity without heat or without moving parts.

1953 - THE DREAM BECOMES REAL

Gerald Pearson, Daryl Chapin, and Calvin Fuller (left-to-right), the principle discoverers of the silicon solar cell, the first material to directly convert enough sunlight into electricity to run electrical devices, measure electrical energy produced by one of their first cells under a lamp.
(with permission from ATT Bell Labs)
In spring 1953, while researching silicon for its possible applications in electronics, Gerald Pearson, an empirical physicist at Bell Laboratories, inadvertently made a solar cell that was far more efficient than solar cells made from selenium. Two other Bell scientists - Daryl Chapin and Calvin Fuller - refined Pearson's discovery came up with the first solar cell capable of converting enough of the sun's energy into power to run everyday electrical equipment. Reporting the Bell discovery, The New York Times praised it as "the beginning of a new era, leading eventually to the realization of harnessing the almost limitless energy of the sun for the uses of civilization.
1956 Searching for Applications
During the first years after the discovery of the silicon solar cell, its prohibitive cost kept it out of the electrical power market. Desperate to find commercial outlets for solar cells, novelty items such as toys and radios run by solar cells were manufactured and sold as this advertisement illustrates.
Although technical progress of silicon solar cells continued at breakneck speed - doubling their efficiency in eighteen months - commercial success eluded the Bell solar cell. A one-watt cell cost almost $300 per watt in 1956 while a commercial power plant cost 50 cents a watt to build at that time. The only demand for silicon solar cells came from radio and toy manufacturers to power miniature ships in wading pools, propellers of model DC-4's, and beach radios. With solar cells running only playthings, Daryl Chapin could not help but wonder, "What to do with our new baby?"
Late 1950s - Saved by the Space Race
The late Dr. Hans Ziegler, the chief advocate for powering satellites with silicon solar cells
While efforts to commercialize the silicon solar cell faltered, the Army and Air Force saw the device as the ideal power source for a top-secret project - earth-orbiting satellites. But when the Navy was awarded the task of launching America's first satellite, it rejected solar cells as an untried technology and decided to use chemical batteries as the power source for its Vanguard satellite. The late Dr. Hans Ziegler, probably the world's foremost expert in satellite instrumentation in the late 1950s, strongly differed with the Navy. He argued that conventional batteries would run out of power in days, silencing millions of dollar worth of electronic equipment. In contrast, solar cells could power a satellite for years. Through an unrelenting crusade led by Dr. Ziegler to get the Navy to change its mind, the Navy finally relented and as a compromise, put a dual power system of chemical batteries and silicon solar cells on the Vanguard. Just as Ziegler predicted, the batteries failed after a week or so, but the silicon solar cells kept the Vanguard communicating with Earth for years.

Early 1960s - Bringing Solar Cells Down to Earth
Hoffman Electronics, the leading manufacturer of silicon solar cells in the 1950s and 1960s, showed a variety of space satellites powered by the sun in a company brochure.
Despite solar cells' success in powering both American and Soviet satellites during the 1950s and early 1960s, many at NASA doubted the technology's ability to power its more ambitious space ventures. The agency viewed solar cells as merely a stopgap measure until nuclear power systems became available. But solar engineers proved the skeptics wrong. They met the increasing power demands by designing ever larger and more powerful solar cell arrays. Nuclear energy, in contrast, never powered more than a handful of satellites. Hence, since the late 1960s, solar cells have become the accepted power source for the world's satellites. The increasing demand for solar cells in space opened an increasing and relatively large business for those manufacturing solar cells. Even more significantly, our past, present and future application of space would have been impossible if not for solar cells. The telecommunication revolution would never have gotten off the ground if not for solar powered satellites. Unbeknown to most, solar energy has played a crucial role in society's technological progress over the past forty years.
Early 1970s - The First Mass Earth Market
Solar cells power navigation warning lights and horns on most off-shore gas and oil rigs throughout the world
While the use of solar cells in space flourished during the 1960s and early 1970s, down on Earth electricity from the sun seemed as distant as ever. Cost was never a factor for space cells. Manufacturers worried more about size, efficiency and durability: the cost of the launch, and the continuing operation of equipment once in space far outweighed the price of power in space applications. But on Earth, the primary criteria is price per kilowatt hour. Solar-cell technology proved too expensive for terrestrial use until the early 1970s when Dr. Elliot Berman, with financial help from Exxon Corporation, designed a significantly less costly solar cell by using a poorer grade of silicon and packaging the cells with cheaper materials. Bringing the price down from $100 a watt to $20 per watt, solar cells could now compete in situations where people needed electricity distant from power lines. Off-shore oil rigs, for example, required warning lights and horns to prevent ships from running into them but had no power other than toxic, cumbersome, short-lived batteries. Compared to their installation, maintenance and replacement, solar modules proved a bargain. Many gas and oil fields on land but far away from power lines needed small amounts of electricity to combat corrosion in well heads and piping. Once again, electricity from the sun saved the day. Major purchases of solar modules by the gas and oil industry gave the fledgling terrestrial solar cell industry the needed capital to persevere.
1970s - Captain Lomer's Saga
Solar cells power the lights of almost every lighthouse run by the U.S. Coast Guard
It cost the Coast Guard more money to install, maintain and replace the non rechargeable batteries that powered its buoys than the buoys themselves. A brave Coast Guard officer, then Lieutenant Commander Lloyd Lomer, who had training in optics and physics, believed that their replacement by solar modules could save taxpayers millions of dollars and do the job better. But his commander refused to listen. Exasperated by such stonewalling, Lomer finally appealed to higher authorities and got the nod to solarize the Coast Guard's navigational aids. President Ronald Reagan commended Lomer for "saving a substantial amount of the taxpayer's money through your initiative and managerial effectiveness as project manager for the conversion of aids to navigation from battery to solar photovoltaic power." Thanks to Lomer's persistence, not only does the U.S. Coast Guard rely almost entirely on solar power for all of its buoys and light houses but so do all the other Coast Guards throughout the world.
1974 - Working on the Railroad
The first solar-powered crossing depicted in this picture began operating at Rex, Georgia in 1974 for the Southern Railway (now the Norfolk/Southern)
When the Southern Railway put in solar modules to power warning lights at a railroad crossing near Rex, Georgia, the railroad had so little confidence that the cells would work that they also connected the lights to a utility line for back up. But that winter, ice build up on the wires caused them to fall, and the only electricity in Rex, Georgia came from the solar array. Around the same time, novel telecommunication systems such as microwave repeaters had made telephone and power poles that followed the tracks obsolete. and many railroad lines wanted to remove these poles to save on maintenance. To avoid train accidents, the railroads still needed a few watts here and there to power signaling and shunting equipment along their lines. Word spread about the Southern's success with solar, leading many lines in the United States and throughout the world to choose the sun to run on site their track safety devices rather than waste huge sums to bring in distant centrally-generated electricity.
Late 1970s - Long Distance for Everyone
One of Telecom Australia's (now Telstra) many solar-powered microwave repeaters, whose installation began in the late 1970s, to provide Australians living in remote areas with same high-quality telecommunication service as those living in larger cities such as Sydney and Melbourne had.
In the early 1970s, the Australian government mandated Telecom Australia, the quasi-public agency in charge of the nation's telecommunications, to provide every citizen, no matter how remotely situated, with the same high-quality telephone and television service that those living in urban areas took for granted. To accomplish the mandate, Telecom Australia searched for an reliable stand-alone power source to run rural telephones and microwave repeater stations. Generators and wind machines did not pass muster. Fortunately, solar cells had come down in price to put them in the running as well. Putting them through a vigorous testing program, Telecom Australia came up with a module design that would only need periodic servicing checks despite the harsh conditions of the Australian outback. Thirteen solar-powered repeaters went up in 1978, each situated twenty-five miles apart. They worked so well that Telecom Australia put up seventy more - the longest network consisting of forty three repeaters spanning fifteen hundred miles. The Australian experience helped make, by 1985, solar modules the power system of choice for remote telecommunications.
1970s - Father Verspieren Preaches the Solar Gospel
The "perfect marriage" of sun and water, made possible by solar cells, made the sun a friend, rather than an enemy, in the drought-stricken sub-Sahara, by providing, instead of denying, precious water for people and livestock.
Dominique Campana, a graduate student in Paris in the 1970s, came up with the idea of applying solar cells to pump water. French physicist Jean Roger translated her concept into a working prototype on the island of Corsica. People from all over the world concerned about supplying healthy water to those where no power existed came to see the solar-run pump. Among the visitors was Father Verspieren - a French priest whom the Malian government put in charge to tap the deep aquifers that run underneath the sands of Mali to save the country then suffering from the worst drought of the twentieth century. After viewing the Corsican installation, Verspieren saw the sun as the solution, not the problem. Starting in the late 1970s, Verspieren initiated a solar water pumping program that has become the template for success in the developing world. Fewer than ten pumps powered by solar cells existed in the world when Father Verspieren installed his first in Mali. Now, tens of thousands power pumps on every continent. As one expert stated, "Thank you, Father Verspieren that today we have lots of solar pumps everywhere and for showing the international community that solar cells are an excellent power source for the people of Africa and the rest of the developing world.
1980s - Electrifying the Unelectrified
A common sight in French Polynesia: solar modules on thatched roofs
From the 1960s through the 1980s, experts planned to power rural parts of the developing world - where the majority live - according to the Western model: build centralized generating plants and by networks of wires transmit the electricity to consumers. But constructing such networks has proven too costly, leaving billions of rural people without electricity. These people have had to rely on costly and inadequate ad hoc solutions to light their homes and power their appliances such as kerosene lamps, automobile batteries and generators. In many cases, solar cells have provided to those living far away from electrical lines the means to obtain higher quality lighting and more reliable power. Since 1983, half of the households in the outlying islands of Tahiti have relied on solar-generated power. More rural Kenyans use electricity from the sun than that offered by the national utility. At least one hundred thousand families in Mexico, Central America and the West Indies run their lights, television sets, and radios with solar electricity. These successes has led the World Energy Council, the international organization of utilities, to recognize, "Solar cells for use at individual houses are a very important development that warrants particular attention as they are ideal for low-power rural applications.
1980s - Solarizing the Electrified
Solar electric modules cover the rooftops of this apartment complex in Bremen, Germany
When governments of developing countries began to fund solar energy programs in the mid-1970s and early 1980s, they favored large-scale, centralized solar-cell plants. Since engineers can tailor solar electric modules to any particular electrical need at the site of use, many came to realize that solar cells could allow each building to become its own electrical power plant by placing them on the roof. This would eliminate much of the capital costs inherent in constructing a centralized power plant such as buying land, putting up transmission lines, laying foundations and support structures and so on. Swiss engineer Marcus Real proved the economic advantages of the micro approach by selling 333 rooftop solar systems to homeowners in Zurich, Switzerland. After the success at Zurich, no one talks about centralized solar-cell plants anymore. Instead, governments are developing financial incentives to encourage homeowners to place modules on their rooftops. Architects and builders can use solar-cell material to build with, becoming facades, roofing, walls and windows. This eliminates a lot of duplication and extra work. For such reasons, Architectural Record lauds this approach as "a cost-effective energy option that architects should routinely consider.
1990s - Better Cells, Cheaper Cells
Tubular octagons of crystalline silicon shaped in a die eliminate much of the expense of producing solar cells.
As the price of solar cells has dropped over the years, they have become the least expensive power source for small-scale electrical demands located away from utility lines. Solar cells have also proven a cheaper source of electricity whenever people have to excavate to lay utility lines underground. Solar cells have therefore saved taxpayers millions in powering emergency call boxes along highways. When a new bus shelter goes up, cities have discovered that it costs less to install solar cells to keep it lit at night than to dig up pavement for the placement of power lines. For the same reason, many municipalities or the highway departments choose solar cells to run street lamps or warning lights. However, solar electricity still costs more to generate than power from existing overhead utility lines. Many believe that current production methods - growing silicon into cylinders or casting them as ingots and then cutting them into very small pieces - cost too much to ever bring down the price to compete with centrally-generated electricity. To dramatically bring down their price, solar cell companies have invested a lot of money to somehow either grow the silicon into a shape that eliminates most of the slicing or merely deposit solar cell material onto an inexpensive but rigid support structure such as ceramic, glass, plastic, or steel.
The Silent Revolution Continues...
With its wing covered entirely by solar cells, the Pathfinder has flown higher than any other aircraft except for the famous spy plane, the Blackbird.
The solar-cell industry has grown dramatically over the last twenty years, increasing output 200 fold in this time period. Today, those needing power in remote areas no longer regard solar cells as an alternative source of energy but consider them the most effective solution. Institutions like the World Bank now believe that solar cells "have an important and growing part to play in providing electrical services to the developing world." In less developed countries, where over half of the population must travel over two hours just to make a phone call, the United Nations today sees solar cells offering these people "for the first time a real practical possibility of reliable telecommunications for general use. Opportunities for solar cells in the developed world continue to grow as well. Solar cells produce electricity than highly polluting diesel generators. The National Parks Service and Defense Department have begun to replace their generators with solar cells. No longer on the highways or roads do portable generators power portable signs warning motorists of lane closures or other important news. Solar cells have replaced them. As the increasing demand for electricity starts to clog the world's power lines, like traffic jams on our freeways, solar cells strategically built on or into homes and buildings can provide the much needed electricity without further burdening the old electrical routes. Or at times, like on a hot August afternoon, when the electrical highways have emptied, mini-electrical plants consisting of solar modules can refill transmission lines to prevent brownouts and blackouts. The skyrocketing price of oil and natural gas and their dwindling supplies as world demand continues to grow will force the world to use more and more electricity generated by the sun. The change from fossil fuels to solar cells will also help clean up our polluted skies and keep a lid on global warming. As Science magazine wrote more than twenty years ago, "If there is a dream solar technology, it is solar cells, a space-age electronic marvel at once the most sophisticated solar technology and the simplest, most environmentally benign source of electricity yet conceived.

Thin film solar tech to undercut cost of fossil fuels within five years

Thin film solar tech to undercut cost of fossil fuels within five years

Solar panels that will be more efficient and a whole lot cheaper are on their way, ready to match the cost of old-fashioned fossil fuels within five years. The secret? Researchers are moving away from heavy silicon solar panels and changing the entire solar energy equation with thin-film solar panels made of rolls of dark polymer foil that can be mass-produced in any color. The thin film has already seen some great uses, such as keeping beer cooler.
Even though solar technology has made significant gains since the 1970s when it cost $100 per watt (now it's $3 to $4 per watt), that sweet spot of beating out fossil fuels is $1 per watt. Swiss entrepreneur Anil Sethi says his solar foil can hit that magic number for even less than that — $0.80/watt — within five years and beat the cost of fossil fuels by 50% in 10 years. There are even more benefits to this groundbreaking tech, including one key factor:
Because these newfangled rolls of foil are 200 times lighter than their silicon-based predecessors, they can even be attached to the sides of buildings. Best of all, the thin film will even work well on a cloudy day. Power companies must be trembling at this development, where a huge percentage of their customers might soon turn the tables, selling power back to them.

LIGHTING RETROFIT-

LIGHTING RETROFIT-
FOR ME OR NOT FOR ME?

The following actual quotation excerpts are representative of the type of savings that lighting retrofit can achieve for the building owner:

"…this quotation for Lighting Retrofit is the result of the energy conservation audit that was performed at your building. As you will see, the potential savings ensuring from Lighting Retrofit are substantial and the investment payback significant. Since Hydro rates have increased over 30% in the past 9 years, these figures serve to highlight the necessity of reducing the consumption of electricity through new lighting technology".

"…current annual lighting costs are $20,700.00 and consume 258,750 kilowatt hours (KwH) of hydro. After the lighting fixture retrofit, the new lighting costs will be $10,200.00 and consume 127,500 KwH. Therefore, your annual savings will be $10,500.00 ($875.00) each month) and 131,250KwH of electricity - 50%. Of course, as hydro rates increase in future years, your savings will increase too".

"…the turnkey retrofit cost is $24,650.00 which yields a purchase payback of 28 months. If you wish, various leasing options are also available. A suggested lease would consist of 36 payments of $860.00 each month so that the lease can be paid by your hydro savings. After 3 years the full $10,500.00 annual savings, or more, is yours".

So, on a financial basis, if the answer to the title question appears to be yes, let's look at what lighting retrofit does.

Lighting retrofit is the changing of particular lighting fixture's component parts or the actual replacement of the entire fixture in order to achieve a reduction in the consumption of electrically. This is fine from Ontario Hydro's point-of-view (they employ Energy Advisors to assist their customers in reducing electrical usage) but, more importantly to you, there is a significant decrease in your Hydro bills. And all without compromising light levels or quality of light output.

The introduction of the fluorescent lamp in the 1930s was the first step towards the development of energy efficient lighting systems. Since then lighting technology has improved and most recently we have seen the introduction of tri-phosphor lamps and electronic ballasts. For over half-a-century electromagnetic ballasts were the only available means of controlling fluorescent lamps. The introduction of electronic ballasts as an alternative is affecting today's fluorescent lighting systems design.

The new technology ballasts and fluorescent lamps produce the same amount of light, or more, at lower wattages and, because more energy is converted to light and less heat is generated, there is a reduced air-conditioning load and lower operating costs. The lamps are available in the same colour temperatures as regular lamps (ie. CW, WW, etc.) but have a much higher Colour Rendering Index (CRI) due to the use of rare earth phosphors which in fact improve the appearance of objects and people seen in this light.

The following items are the most common forms of retrofit for the building owner:

1) The replacement of existing old style T12 (1½" dia.) fluorescent lamps and electromagnetic (core and coil) ballasts with new technology T8 (1" dia.) lamps and electronic or energy saving electromagnetic ballasts. A typical 4' 2-lamp 93 watt fixture would be retrofitted to either 58 or 71 watts, depending on the ballast used.

2) The reduction in the number of lamps in a fixture, usually in conjunction with the above item, and the addition of a pre-formed anodized aluminum reflector. A 4' 4-lamp 186 watt fixture could be retrofitted to 2 lamps at 58 watts total along with the addition of a reflector to maintain acceptable light levels - a saving s of 69%. If the current fixture was burning 24 hours a day every day of the year it would cost you $130.00 annually - just for one fixture! Wouldn't you like to reduce that to $40.00?

3) The replacement of interior and exterior 60, 75, 100 and 150 watt "A" bulbs and PAR 38 pot lamps with compact fluorescent 9, 13, 18 or 26 watt lamps or new fixtures. Besides the great lessening of wattages and therefore dollars, the amount of heat that is no longer produced is notable. Also, there is a reduction in lamp cost and labour replacement time because of the 10 times longer life.

4) The replacement of the two 15 watt bulbs in Exit signs with two 1 watt LED lamps or strips rated at 25 years. Put them in and forget them! The costs are $1.40 per Exit sign per year instead of an annual operating cost of $21.00 each plus you won't have to worry that the Fire Marshall will inspect the building and find burnt-out signs.

5) The replacement of exterior wall mounted and pole mounted incandescent, quartz and mercury vapour fixtures with either metal halide or high pressure sodium fixtures. Besides the increased light levels and occupant satisfaction, the savings in kilowatts and hydro costs are very meaningful.

Where can the building owner use this new lighting technology? Wherever interior lights are on more than 8 to 12 hours a day. Areas such as offices, classrooms, lobbies, washrooms, health/fitness rooms, lockers, utility/mechanical rooms, etc… Common areas such as hallways, stairwells and garages are on 24 hours a day, every day of the year - that is, always! And the exterior lights are basically on half of always!

If you think that lighting retrofit makes sense for your building, contact an energy management company. Have them perform a lighting audit which will detail the fixtures by location and consumption. It should indicate the retrofit status of each fixture type and show the current and new kilowatt demand and kilowatt hours of consumption. From this and the quoted installed cost, the savings and the payback timeframe can be determined. It should be apparent that the benefits of lighting retrofit are there for your building.

The ASHRAE/IES 90.1 Standard

The ASHRAE/IES 90.1 Standard

Scope

ASHRAE/IES 90.1 deals only with commercial and high-rise residential buildings. It sets minimum performance standards for building systems and components which have an impact on building energy consumption, including the building envelope, heating, ventilation and air-conditioning (HVAC) systems, and lighting. For lighting systems,the standard defines a number of basic requirements, including: minimum number of lighting controls, ballast performance, and limits on installed lighting power. This chapter concentrates on the limits on installed lighting power. Table 1 shows the current typical installed lighting power for several applications [9], and typical guideline values for the same application from the standard.* In many cases the guideline value is significantly lower than the current typical value. However, the standard values were derived, by consensus of lighting experts, from technologies that can be adopted cost-effectively, and not from "state-of-the-art" technologies; the standard stops well short of what is technically feasible. The standard does recognize that certain applications might require more power than others to effectively light the space. For example, compare the standard guidelines for "retail display" and "lobby."

Table 1. Typical current lighting power densities for various applications, and typical guideline values from the standard

Application	Current (W/ft2)	ASHRAE/IES 90.1 (W/ft2)
Office tower	2 to 4	1.50
Lobby	2 to 5	1.00
Open-plan office	3 to 4	1.90
Drafting studio	?	2.60
Boardroom	3 to 6	1.80
Parking lot	0.1 to 0.2	0.18
Shopping mall
Concourse	3.6	1.40
Retail display	6 to 10	3.10
Car showroom	2.5 to 6	2.80
Operating theatre	7	7.00

* The ASHRAE/IES standard is published in imperial units only. For that reason, the normal NRC practice of publishing in metric units has not been followed in this chapter.

Lighting and Electrical Demand

Lighting and Electrical Demand

There are good reasons why we should curb our energy appetites, but where does lighting fit into the Canadian energy consumption picture? Residential and commercial buildings consume about 36% of all the energy consumed in Canada (Figure 1) [4]. And lighting is responsible for about 30% of all energy consumed in commercial buildings (Figure 2) [5]. The cost of lighting Canadian commercial buildings is very high, perhaps as high as $2 billion annually, equivalent to the total output of eight 1000 MW power stations. Yet the technology exists to cost-effectively reduce lighting energy consumption significantly, while maintaining, or even improving, lighting quality. Clearly, lighting is an appropriate target for energy conservation efforts.

Figure 1. Canadian energy consumption by sector

Figure 2. Typical Canadian commercial building energy consumption by end-use

New Energy Guidelines

Origins of the guidelines

Two energy guidelines are discussed in this paper: the ASHRAE/IES 90.1 Standard[6] and the Canadian Code for Energy Efficiency in New Buildings. The evolution of these guidelines began in 1975 with the publication of ASHRAE 90[7], in response to the energy crisis of the early 1970s. It contained recommendations, by consensus of experts, for the construction of energy efficient buildings. In 1978 the document Measures for Energy Conservation in New Buildings[8] was published in Canada. This document was based on ASHRAE 90 but with more emphasis on the economics of energy efficient design. However, neither of these documents contained much about lighting, and neither achieved widespread adoption into building codes; Measures for Energy Conservation in New Buildings was adopted only by the province of Québec. In 1989, the IES (Illuminating Engineering Society) joined ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers) in producing ASHRAE/IES 90.1. This standard updated the recommendations of ASHRAE 90 and, as one might expect, given the co-authorship of IES, contained a whole chapter on energy efficient lighting. An update to ASHRAE/IES 90.1 is expected in 1993.

Work on the Canadian Code for Energy Efficiency in New Buildings began in 1990. Following public review, the new Canadian code will be published in 1995 as a companion document to the National Building Code of Canada. It will then be passed on to the provinces and municipalities for consideration and adoption into local building codes, a process that could take up to two years. A number of provinces and municipalities have already adopted ASHRAE/ IES 90.1 into their building codes, among them, the city of Vancouver, and the province of Ontario.

Although the lighting part of the new Canadian code will be largely based on the ASHRAE/IES 90.1 standard, there will be significant differences. Since the Canadian energy code is still a "work-in-progress," the rest of this chapter describes the ASHRAE/IES 90.1 standard.

New Energy Codes

New Energy Codes and Their Impact on Lighting Design

Introduction

Many Canadian provinces and municipalities will adopt, or have already adopted, new energy codes or standards for commercial buildings, with the aim of reducing building energy consumption. The principal effect of these codes on lighting design is to set limits on installed lighting power in buildings. As these limits are significantly lower than typical current designs, the codes will encourage the adoption of energy efficient lighting technologies.

The Energy Crisis of the 1990s

There have been energy crises of one form or another throughout history. Most, like the energy crisis of the early 1970s, were caused by a lack of fuel supply. The crisis of the early 1970s spawned much research into energy conservation and renewable energy sources, in an effort to reduce dependence on fuel sources then deemed unreliable. After an oil glut in the 1980s, we now find ourselves in another effort to save energy. However, this latest crisis is not due principally to limited fuel supplies. While it is certainly true that traditional fuel supplies have finite lifetimes, they will not run out tomorrow. For example, estimates of world oil reserves range from 76 to 164 years at present rates of production [1], and the lifetime of the reserves of other traditional fuels is probably at least as long. Suppliers of energy now face more immediate environmental, political and economic pressures.

Principal among these pressures, certainly as far as the public is concerned, is the environmental impact of energy generation. Though the effects may vary in form and degree, every method of energy generation has an environmental impact, particularly those which generate electricity on a large scale:

• Traditional fossil fuel power stations are notorious for the pollutants which they discharge into the environment [2]: carbon dioxide, which is the major "greenhouse" gas; sulphur dioxide and nitrous oxides, which produce acid rain; and volatile organic compounds and particulate matter.
• Nuclear power (fission) was once regarded as the "clean" successor to fossil fuel burning, but accidents have shaken public confidence, and the problem of radioactive waste disposal remains.
• Hydro-electric power makes a significant contribution to electricity generation in several Canadian provinces, and is largely viewed as environmentally benign. However, hydro-electric generation detrimentally affects the environment by flooding large areas and changing ecosystems.

Governments, reacting to the public concerns over the environmental impact of energy generation, have sought to encourage energy conservation, and more "environmentally friendly" ways of generating energy.

Utilities too have demonstrated a growing interest in energy conservation, principally for economic reasons. The capital cost of construction, environmental impact assessments and public inquiries make building new generating capacity very expensive [3]. Hence, many Canadian electrical utilities, with forecasts of increasing future demand for energy, have embarked on vigorous demand side management (DSM) programs. DSM programs promote energy conservation and, if successful, offset the need to build new generating capacity. Many of the more successful DSM programs have been aimed specifically at lighting. These programs often offer cash rebates for the adoption of energy efficient lighting technologies; utilities find this a cheaper alternative to building the generating capacity to meet a growing demand.

small light-emitting diode

Osram has developed a small light-emitting diode spotlight that achieves an output of more than 1,000 lumens for the first time. That’s brighter than a 50-watt halogen lamp, thereby making the device suitable for a broad range of general lighting applications. The Ostar Lighting LED, which will be launched on the market this summer, can provide sufficient light for a desk from a height of two meters, for example. Its small size also enables the creation of completely new lamp shapes. Source: Siemens

Osram has developed a small light-emitting diode spotlight that achieves an output of more than 1,000 lumens for the first time. That’s brighter than a 50-watt halogen lamp, thereby making the device suitable for a broad range of general lighting applications.

A lumen (lm) is the unit of measurement for the amount of light emitted by a light source. A 60-watt light bulb emits 730 lm, while a 50-watt halogen lamp has an output of approximately 900 lm. To achieve the 1,000 lm output for the tiny Ostar Lighting LED, the experts at Siemens’ Osram subsidiary employed a sophisticated system for high chip-packing density, whereby the researchers managed to integrate six high-performance LED lighting chips into the unit’s small housing. Each chip has an area of only one square millimeter, which makes for very concentrated overall luminosity.

Different types of LEDs are used today in various areas, for example as background lighting in cell phone displays, as well as in car turn-signal lights, brake lights, and daytime running lights. The benefits are obvious: The diodes are extremely small and consume little energy because they efficiently convert electricity into light. The Ostar Lighting LED, for example, produces 75 lumens per watt at 350 milli-amperes of operating current — much more than an incandescent lamp, which only converts a fraction of the electricity supplied into light, with the rest lost as heat energy. In addition, LEDs contain no lead or mercury, which makes them very environmentally friendly. They also last around ten times longer than halogen lamps and 50 times longer than incandescent lamps, thereby helping to significantly reduce maintenance costs.

For many years, however, LEDs were unsuited for room lighting applications because they weren’t bright enough. The Ostar Lighting LED marks a further step toward suitability for such applications. Osram has already supplied a Migros supermarket in the Swiss canton of St. Gallen with 18,000 Golden Dragon LEDs, which have a lower output than the Ostar Lighting units. These LEDs emit neither UV rays nor heat, which means they have virtually no negative impact on delicate grocery items such as milk, meat, fruit and vegetables.

Ballasts

Ballasts

A common mistake made is to use instant-start ballasts for switching applications when upgrading fluorescent systems. Lamp life can be shortened for fluorescent systems that are switched with occupancy sensors. The new program-start ballasts designs are recommended instead.

Program-start ballasts extend lamp-operating life and reduce replacement lamp cost. This new ballast design precisely controls the timing of the application of starting and warming cathode voltage to the lamp. Program-start ballasts can outperform rapid-start ballasts by providing from 50,000 to 100,000 starts and an estimated 50% longer lamp life. Buildings commonly have different fluorescent lighting system voltages in various parts of the facility. Many older systems were originally 120-V incandescent that were later converted to fluorescent systems. Later, newer parts of the building often had a 277-V fluorescent system.

New models of electronic ballasts feature universal input voltage that will accept any line voltage between 120-277 V. Input circuitry automatically uses the applied voltage without special taps or switches.

Maintenance personnel can save valuable time when replacing a failed ballast because they don't have to stop and figure out which lighting system voltage applies.

The traditional lighting design for conference rooms has two lighting systems. An incandescent system usually uses recessed cans and is dimmed with wall dimmers. A fixed-light fluorescent system is installed for ambient lighting.

Affordable, line-voltage fluorescent dimming ballasts provide a single system solution. The overhead incandescent system can be removed and the ballasts in the fluorescent system can be replaced with line-voltage dimming ballasts that connect to the existing incandescent wall-box dimmer(s). Lower maintenance cost is the principal benefit.

Metal Halide

Metal Halide

Higher-wattage, pulse-start metal halide lamps support and drive the trend toward white light and, along with ceramic metal halide lamps, are expected to replace incandescent and halogen sources.

Standard metal halide lamps in the 175-1000-W range that make up 70% of existing applications are expected to be replaced by either pulse start lamps or with the expanding family of ceramic metal halide (CMH) lamps.

Low-wattage metal-halide lamps and all high-pressure sodium (HPS) never used starting probes. Instead, they use a proven pulse starter to start the lamps. This starting method is not new--what is new is its use in higher-wattage metal halide lamps.

Standard (probe-start) metal halide lamps use a bi-metal switch inside the lamp to disconnect the starting electrode once the HID lamp is warmed up, which is eliminated in the pulse-start models. The best pulse-start lamp performance results are from a new family of lamps based on formed body arc tubes.

Formed body arc tubes feature higher fill pressures and more uniform geometry than pinched arc seal tubes. Temperature control is improved, which reduces lamp-to-lamp color shift. Design changes result in up to 80% higher lumen maintenance, up to 110 lm/W efficacy, 50% faster warm up and restrike, longer life, and more consistent lamp-to-lamp color.

Ceramic arc tube metal halide lamps, commonly designated CMH or CDM, usually refer to their constant color in their brands. CMH lamps were introduced to eliminate the problem of color shift of standard lamps and use PCA arc tubes--the same material used in HPS lamps. The PCA material reduces the sodium loss that causes color shift.

CMH lamps are commonly available in wattages below 150 W, but 250- and 400-W models are now available. CMH lamps have average rated life of 6000-20,000 hours and their lumen maintenance values fall in the 0.70-0.80 range. Warm (3000 K) or cool (4000 K) color temperatures and improved color rendering (CRI 85 and above) are available.

CMH lamps perform best on electronic ballasts. The advantages of the combination of CMH and electronic ballasts include 10-20% greater light output (which also results in a corresponding higher efficacy) and limited color shift.

T5 Lamps and Ballasts

T5 Lamps and Ballasts

Cove lighting systems can benefit from T5 lamps and their new ballasts. These 5/8-in. diameter lamps are 12-18% more efficacious than T8 lamps, but they are not intended to replace T8 technology. T5 systems are especially suitable for the higher temperatures found in indirect, confined cove systems (where there is little or no air circulation), because they are designed to produce their peak light output at 35 degrees C (95 degrees F) vs. 25 degrees C (77 degrees F) for T12 and T8 lamps.

New ballast models can power one or two standard T5 lamps of any wattage (14, 21, 28, or 35 W), since all lamps in the standard T5 family operate at the same current (170 milliamps). All models have the same surface brightness, so no matter what length lamp is used to fill out the length of the cove (549, 849, 1149, or 1449 millimeters), cove brightness is uniform.

To increase brightness in coves and for other indirect lighting applications, T5HO lamps are recommended. T5HO lamps have the same physical measurements as the lower wattage, standard T5 lamps, but provide higher light output. T5HO lamps generate up to twice the light output of standard T5 lamps and nearly twice the light output of T8 or T12 systems, which allows half the number of lamps to be used.

The surface brightness of T5HO varies with various power ratings (24, 39, 54, and 80 W). The lamps operate on different currents, so each lamp wattage requires a unique ballast. At 83 to 94 lm/W per watt, they are about 10-15% less efficacious than standard T5 lamps and up to 8% less efficacious than T8 systems.

Both standard T5 and T5HO lamps maintain superior light output over time, only losing 5% of their initial lumen rating in the first 40% of rated life. Both lamp types have excellent color rendering index (CRI) ratings greater than 80.

A new, versatile T5HO ballast, designed to operate two, three, or four F54 (~45-in) lamps has been announced. Multi-lamp versatility, remote mounting, and a high-low switching option make this model attractive for many new applications. Dimming ballasts are also available for T5HO lamps.

Improvements in lamps, ballasts, controls

Improvements in lamps, ballasts, controls, and luminaires bring new options

Manufacturers have rapidly introduced a succession of improved lighting technologies in the past few years, but users have been slow to apply them. New models are announced in rapid order, making product selection confusing and overwhelming. Those users who understand the characteristics and advantages of new products will be able to select models that will produce the greatest cost savings for the investment.

New large screw-base compact fluorescent lamps (CFL) include the following models, which can be used in high-ceiling applications to replace 200-300-watt (W) incandescent lamps. Each model is rated at 65 lumens-per-watt (lm/W).

A new four-pin, rapid-start CFL, rated at 4300 lm (light output equivalent to a 200-W incandescent lamp) is also intended for high-ceiling applications. Electronic ballasts are available, and at least one company offers a matching lamp and ballast system.

ElectroCeramescent Lighting

A Promising New Technology—ElectroCeramescent Lighting

Solid-state ceramic light using Electro-Ceramescent lighting technology is displayed on a sign at DOE's National Energy Technology Laboratory in Morgantown, West Virginia

Most illuminated commercial signage utilize conventional technologies, such as incandescent or fluorescent lamps, for its illumination. A promising new lighting technology, called ElectroCeramescent (ECer) lamps may lead to dramatic power reduction and improved illumination. Developed by Meadow River Enterprises, Inc., in collaboration with the U.S. Department of Energy, the New York State College of Ceramics at Alfred University, Marshall University, and Osram-Sylvania, ECer lighting reduces the power requirement for typical commercial signs by as much as 90 percent.

The typical efficiency of incandescent and fluorescent lights is 15 and 75 lumens per watt, respectively. While the efficiency of an ECer lamp can be as low as 4 lumens per watt, even a low efficiency ECer lamp uses dramatically less power than conventional light sources for a given task. ECer signage is equally visible at lower overall power consumption, because the source of the light is directly viewed, rather than a reflection. A 4-foot x 14-foot sign using conventional T-12 high output fluorescent lamps would require 550 watts. ECer technology reduces the power demand to less than 12.5 watts by forming letters and symbols with laser-cut ECer lamp panels, thus lighting individual characters rather than the entire sign. Unlike incandescent and fluorescent lamps, the flat and uniformly lit ECer lamp produces virtually no heat, glare, or halo even in adverse weather conditions, so little light is wasted. Reflected light configurations, widely used for illuminated signage, waste much of their energy in heat and by lighting the ground or sky—a significant source of light pollution.

The solution to light pollution lies in quality lighting systems that enhance nighttime ambiance rather than reproducing inappropriate daylight conditions. A powerful design approach is to directly light the surface of objects that need to be visible with minimal use of reflected light, and matching its spectra to human eye sensitivities. Because the required light levels (and power demands) of signage can be remarkably low, surface light sources and associated fixture design are the critical parameters. ECer lighting systems can dramatically reduce unnecessary nighttime illumination, while cutting energy consumption and improving visibility. This produces a better, more visible sign with reduced energy use.

Ban on Inefficient Light Bulbs

Electric lighting is an essential part of our daily lives, but it is also one of the most energy-intensive. More than 10 percent of the energy we consume in our homes is used to provide light, most of it produced by the familiar, but very inefficient, incandescent light bulb. The incandescent bulb was developed in the 19^th century, and the technology behind it has changed very little over the past 100 years.

Today, a number of alternative lighting technologies exist that offer excellent performance while consuming far less energy. By switching to these new lighting technologies, Canadians can reduce their energy costs and achieve a substantial reduction in the emission of greenhouse gases and other harmful substances.

Recognizing these benefits, Canada's New Government has committed to setting performance standards for all lighting that would phase out the use of inefficient light bulbs in common applications by 2012.

Canada is proposing an approach that involves stakeholders such as provincial and territorial governments, electric utilities, manufacturers and distributors that will result in the definition of a standard by the end of 2007, including timelines so that low-efficiency lighting would be eliminated by 2012. Because the lighting market is global in scope and other jurisdictions are contemplating similar measures, Canada's objective is to ensure that efforts are harmonized with those of our trading partners.

The technology to achieve this goal already exists, and more innovations are on the horizon. Already-available replacements for incandescent bulbs include compact fluorescent light bulbs (CFLs), high-efficiency halogen bulbs, light-emitting diodes (LED) lights and others that produce the same amount of light while consuming less energy. ENERGYSTAR®-qualified compact fluorescent bulbs, for example, use only about one-quarter as much electricity as a conventional light bulb to produce the same amount of light. Although they do cost a bit more, CFLs can last up to ten times longer than an incandescent bulb, paying for themselves many times over in energy savings and convenience.

It has been estimated that, if every Canadian replaced just one of the most used incandescent light bulbs in their home with an ENERGYSTAR®-qualified compact fluorescent bulb, the energy savings would amount to more than $73 million, and emissions of greenhouse gases would be reduced by 400,000 tonnes.

By banning inefficient light bulbs, consumers will have confidence that the lighting they choose meets a minimum requirement for efficiency. The new standards will also provide certainty for manufacturers and support those who invest in the development of innovative new products to meet regulatory and consumer demand for efficient, effective and attractive lighting.

The lighting-efficiency standards will be complemented by new regulations for light bulb packaging that will make shopping for the best and most efficient lighting even easier. The new packaging standards will allow Canadians to shop for bulbs according to how much light they produce, as well as how much energy they consume, making it easier to choose the right bulb and the most efficient bulb for specific uses.

Through the Energy Efficiency Act, the Government of Canada has regulated the efficiency of a number of lighting products, including linear fluorescents, incandescent reflector lamps, exit signs and others, for more than a decade. This new standard broadens the regulations to include the most common general-area lighting products sold in Canada.

The ban on inefficient light bulbs and the new labelling standards for bulbs build on the measures included in the Clean Air Regulatory Agenda, under which the government will set energy-efficiency standards and labelling requirements for an increased number of energy-using products. Achieving the same comfort and convenience for less energy is one of the most sensible and effective ways of reducing emissions and saving money.

Like the ecoENERGY Retrofit Initiative that is helping Canadians increase the energy efficiency of their homes, and like the ecoAUTO Rebate program that is helping them purchase more efficient vehicles, the introduction of efficiency standards for lighting sold in Canada is one more way Canada's New Government is helping Canadians use less and live better — and deliver real results on climate change and clean air.

LED lighting to a new level

The main light source of the future will almost surely not be a bulb. It might be a table, a wall, or even a fork.

An accidental discovery announced this week has taken LED lighting to a new level, suggesting it could soon offer a cheaper, longer-lasting alternative to the traditional light bulb. The miniature breakthrough adds to a growing trend that is likely to eventually make Thomas Edison's bright invention obsolete.

LEDs are already used in traffic lights, flashlights, and architectural lighting. They are flexible and operate less expensively than traditional lighting.

Happy accident

Michael Bowers, a graduate student at Vanderbilt University, was just trying to make really small quantum dots, which are crystals generally only a few nanometers big. That's less than 1/1000th the width of a human hair.

Quantum dots contain anywhere from 100 to 1,000 electrons. They're easily excited bundles of energy, and the smaller they are, the more excited they get. Each dot in Bower's particular batch was exceptionally small, containing only 33 or 34 pairs of atoms.

When you shine a light on quantum dots or apply electricity to them, they react by producing their own light, normally a bright, vibrant color. But when Bowers shined a laser on his batch of dots, something unexpected happened.

"I was surprised when a white glow covered the table," Bowers said. "The quantum dots were supposed to emit blue light, but instead they were giving off a beautiful white glow."

Then Bowers and another student got the idea to stir the dots into polyurethane and coat a blue LED light bulb with the mix. The lumpy bulb wasn't pretty, but it produced white light similar to a regular light bulb.

White light from Bowers' lumpy new bulb. Credit: Vanderbilt University

The new device gives off a warm, yellowish-white light that shines twice as bright and lasts 50 times longer than the standard 60 watt light bulb.

This work is published online in the Oct. 18 edition of the Journal of the American Chemical Society.

Better than bulbs

Until the last decade, LEDs could only produce green, red, and yellow light, which limited their use. Then came blue LEDs, which have since been altered to emit white light with a light-blue hue.

LEDs produce twice as much light as a regular 60 watt bulb and burn for over 50,000 hours. The Department of Energy estimates LED lighting could reduce U.S. energy consumption for lighting by 29 percent by 2025. LEDs don't emit much heat, so they're also more energy efficient. And they're much harder to break.

Other scientists have said they expect LEDs to eventually replace standard incandescent bulbs as well as fluorescent and sodium vapor lights.

If the new process can be developed into commercial production, light won't come just from newfangled bulbs. Quantum dot mixtures could be painted on just about anything and electrically excited to produce a rainbow of colors, including white.

One big question remains: When a brilliant idea pops into your mind in the future, what will appear over your head?

History of Photovolatics

History of Photovolatics

The history of PV's dates back to 1839 and major developments evolved as follows:

1839 Edmund Becquerel, a French physicist observed the photovoltaic effect.

1880's Selenium PV cells were built that converted light in the visible spectrum into electricity and were 1% to 2% efficient. Light sensors for cameras are still made from selenium today.

In the early 1950's the Czochralski meter was developed for producing highly pure crystalline silicon.

In 1954 Bell Telephone Laboratories produced a silicon PV cell with a 4% efficiency and later achieved 11% efficiency.

In 1958 the US Vanguard space satellite used a small (less than one watt) array to power its radio. The space program has played an important role in the development of PV's ever since.

During the 1973-74 oil embargo the US Department of Energy funded the Federal Photovoltaic Utilization Program, resulting in the installation and testing of over 3,100 PV systems, many of which are in operation today.

The 1970s through the 1990s have seen a relative disinterest in solar power with majority ownership of many United States PV manufacturers transferring to German and Japanese interests.

The Gulf war of 1990 again sparked Americas interest in non-fossil fuel energy alternatives.

International markets for solar take off in the mid 1990s.

Glossary of Solar and Photovoltaic Terms

Glossary of Solar and Photovoltaic Terms

Cell efficiency - The ratio of the electrical energy produced by a photovoltaic cell (under full sun conditions or 1 kW/m2) to the energy from sunlight falling upon the cell.

Charge controller - A component that controls the flow of current to and from the battery subsystem to protect the batteries from overcharge and over discharge. The charge controller may also monitor system performance and provide system protection.

Diffuse radiation - Sunlight received indirectly as a result of scattering due to clouds, fog, haze, dust or other substances in the atmosphere.

Direct radiation - Light that has traveled in a straight path from the sun (also referred to as beam radiation). An object in the path of direct radiation casts a shadow on a clear day.

Flat-plate array - A photovoltaic array in which the incident solar radiation strikes a flat surface and no concentration of sunlight is involved.

Fresnel Lens - A concentrating lens, positioned above and concave to a PV material to concentrate light on the material.

Grid-connected - An energy producing system connected to the utility transmission grid. (Also called utility interactive.)

Hybrid system - A power system consisting of two or more power generating subsystems (e.g., the combination of a wind turbine and a photovoltaic system).

Insolation - The amount of sunlight reaching an area, usually expressed in watts per square meter per day.

Load - Electrical power being consumed at any given moment. The load that an electric generating system supplies varies greatly with time of day and to some extent season of year. Also, in an electrical circuit, the load is any device or appliance that is using power.

Parallel connected - A method of connection in which positive terminals are connected together and negative terminals are connected together. Current output adds and voltage remains the same. (See also series connected.)

Photovoltaic cell - The semiconductor device that converts light into dc electricity. The building block of photovoltaic modules.

Series connected - A method of connection in which the positive terminal of one device is connected to the negative terminal of another. The voltages add and the current is limited to the least of any device in the string. (See also parallel connected.)

Solar constant - The rate at which energy is received from the sun just outside the earth's atmosphere on a surface perpendicular to the sun's rays. Approximately equal to 1.36 kW/m2.

Thick cells - Conventional cells, such as crystalline silicon cells, which are typically from 4 to 17 mils thick. In contrast, thin-film cells are several microns thick.

Thin-film cells - Photovoltaic cells made from a number of layers of photo-sensitive materials. These layers are typically applied using a chemical vapor deposition process in the presence of an electric field.

Voltage regulator - A device that controls the operating voltage of a photovoltaic array.

Canada to Build 40MW Solar Power Plant

An Ontario company has been given approval to build a 40MW solar power plant near Sarnia in Southwestern Ontario. This is enough power for about 10,000 homes. The plant will cover 365 hectares (1.4 sq. miles) and is to be operational by 2010. OptiSolar, the company building the plant, claims to have developed a way to mass produce the solar panels at a dramatically reduced cost, making the plant competitive with other forms of power generation. 'Compared to coal, nuclear power, even wind, solar's squeaky-clean image comes at a high price. OptiSolar is selling the electricity to the province under its new standard offer program, which pays a premium for electricity that comes from small-scale renewable projects. In the case of wind, it's 11 cents per kilowatt-hour. Solar fetches 42 cents per kilowatt hour, nearly four times as much.

Ontario goes solar

Ontario goes solar

Energy Reporter

The Ontario government has given approval for a California company to construct a massive solar "farm" near Sarnia that will blanket an area larger than all three Toronto islands with hundreds of thousands of sun-soaking panels.

It will be the largest solar power station in North America and among the most expansive in the world to use photovoltaic cells that produce electricity when exposed to sunlight. Once complete, the 40-megawatt Sarnia project will be able to supply enough emission-free electricity to power between 10,000 and 15,000 homes on sunny days.

"This is certainly the most exciting thing I've ever worked on," said Peter Carrie of OptiSolar Farms Canada Inc., a subsidiary of Hayward, Calif.-based OptiSolar Inc. "We want to take solar mainstream."

The Ontario Power Authority has agreed to purchase the electricity under a 20-year contract that will see the clean power go into the provincial grid. An official announcement is expected today from the energy ministry.

The current world record-holder is the 12-megawatt Erlasee solar park in Germany, though another 40-megawatt park is under construction in the same region. On Monday, the largest U.S. project was announced: A 15-megawatt solar PV system to be built at an air force base in Nevada.

The Sarnia solar farm will be enormous by comparison, stretching across nearly 365 hectares, the equivalent of 419 Canadian football fields. An army of panels will be erected as high as seven metres off the ground, all tilted south to soak up sunlight.

In a Canadian context, the magnitude is even more impressive. The 100-kilowatt solar installation atop Exhibition Place's historic Horse Palace, now the largest in Canada, is 400 times smaller than OptiSolar's proposed farm.

The company would not reveal the cost of the project for proprietary reasons, but Carrie said a typical 10-megawatt system runs between $70 million and $80 million. This means the cost of the Sarnia project, to be built in four 10-megawatt phases, could carry a price tag of around $300 million.

"Forty megawatts is huge," said John Stanton, vice-president of government affairs at the U.S. Solar Energy Industries Association in Washington, D.C.

Stanton said solar panel systems, once relegated to the rooftops of homes, farms and commercial buildings, are growing in size as technology costs fall and government incentives increase. "There's also an increasing recognition of the public benefits associated with solar energy production," he said.

"Solar power is carbon-free, it's pollution-free, it doesn't need water, doesn't make noise. Solar also produces power during peak business hours, so it displaces natural gas," he said.

But compared to coal, nuclear power, even wind, solar's squeaky-clean image comes at a high price. OptiSolar is selling the electricity to the province under its new standard offer program, which pays a premium for electricity that comes from small-scale renewable projects. In the case of wind, it's 11 cents per kilowatt-hour. Solar fetches 42 cents per kilowatt hour, nearly four times as much.

Deborah Doncaster, executive director of the Ontario Sustainable Energy Association, said the premium may seem high but is justified given the environmental benefits. She said it's often forgotten that solar-generated electricity tends to offset natural gas during peak periods when air conditioners are blasting and electricity rates are at their highest.

"Forty-two cents compared against 6.4 cents for nuclear is comparing apples to oranges," she said, adding that the publicly touted costs of nuclear power and fossil fuels never reflect environmental costs, health impacts, and industry subsidies.

"I think the issue around 42 cents has to be looked at in the proper context of hidden costs," Doncaster said.

And while large on a solar scale, the Sarnia project is a lightweight compared to nuclear or coal plants. Peak electricity consumption in Ontario yesterday was 18,055 megawatts. OptiSolar's farm could at most supply .2 per cent of that power.

Carrie said OptiSolar chose Ontario over its home base of California, because of the 42-cent offer, which isn't available anywhere else in North America. Only European countries have taken such an approach, explaining why world solar leader Germany installed seven times more solar panels than the United States in 2006.

OptiSolar hopes the premium offered through the Ontario program will give it a return on its investment over the life of its 20-year contract with the province, said Carrie.

The company hopes to break ground in 2008 after getting the necessary municipal zoning approvals and building permits. It has already purchased the real estate it needs, mostly low-value farm and industrial land, and has full backing of the local community.

Carrie said the Sarnia area was chosen because it has the right mix of land and good access to the electrical distribution network. It's also in the most southerly region of Ontario, meaning it offers the best "sun hours."

Solar tends to be a low-maintenance technology, but several local contractors will be hired to help install and connect thousands of solar panels.

"There will also be ongoing contracts for property maintenance, grounds maintenance, security and equipment cleaning," said Carrie, a Canadian and former employee of the energy ministry. He most recently ran his own solar installation business in California.

If all goes according to schedule, the Sarnia solar farm will be fully functional in 2010 and will continue supplying clean electricity to the grid for the next 30 to 50 years.

Not much is known about OptiSolar, though many of its private investors are Canadian. It was co-founded by Randy Goldstein and Phil Rettger, who previously founded the Calgary-based oil sands technology and project developer Opti Canada Inc.

The company says it has developed a way of mass-producing solar cells in a way that dramatically lowers the cost of the technology, making it competitive with conventional forms of electricity generation.

Carrie said the goal in Ontario is to showcase OptiSolar's technology and demonstrate its performance, while at the same time generating revenues from electricity production.

Geothermal

Geothermal

Geothermal or ground source heat pumps take advantage of the stored solar energy in the soil and natural water bodies. They rely on electricity, but provide the equivalent of 3x kW of electrical heat for every kW supplied. Because heat pumps are reversible, providing cooling and heating, they are a useful consideration in areas with substantial cooling load

Photovoltaics (Solar Electricity)

Photovoltaics (Solar Electricity)

Sunlight converted directly to electricity through solar cells is known as photovoltaic (PV) energy. Solar cells come in a variety of sizes and produce electricity as long as light shines on them. Solar cells used for electrical generation are a more sophisticated version of the solar cells used in calculators and other small household electronic devices.

PV cells generate direct current (DC). This means that to use PV generated electricity directly, DC appliances and lights must be used. These are used in recreational vehicles and on boats. Otherwise, to use conventional household appliances the power must be converted to alternating current (AC), which is the form supplied by utilities. This means that a solar electric system has to be designed to convert the power to AC.

Although prices have been reduced dramatically in recent years, and they are still dropping, a PV is system is expensive. They are cost effective for some special applications, especially in remote areas away from utility grids, where you have to generate your own electricity. Recreational vehicles and boats are other common applications.

Because of the higher initial cost of a PV system, a careful electrical load analysis must be done to establish required capacity. The efficiency of appliances to be supplied by the electric system must also be considered. It is usually more cost effective to reduce demand for electricity than to install a larger alternate system.

Active Solar

Active Solar

Active solar systems use solar collectors and a pump or fan to distribute the sun's energy. Active systems are best suited to heating water. The collector is a dark colour to absorb the sun's energy and converts it into heat. Some collectors have glass covers, and collect solar energy year round. Unglazed collectors are typically used for seasonal applications such as swimming pools.

Domestic hot water needs can be met at least in part by active solar systems. In most cases solar energy will only provide some hot water needs in winter, but most of summertime needs. On average, it can provide 50 to 60% of annual domestic hot water needs. In most applications the solar system is used as a preheater for city or well water going to the conventional water heater

Outdoor swimming pools can be entirely heated by solar systems, thus eliminating the need for any auxiliary heater. These systems have a short payback. Plumbing can be connected directly to the pool's filtration system, so there is minimum added equipment that has to be installed.

Passive Solar Heating

Passive Solar Heating

Passive solar is the most cost effective approach to maximizing the use of solar energy for Canadian homes. Passive solar heating of buildings occurs when sunlight passes through a window. The term passive suggests that no additional mechanical equipment is used other than normal building elements. All passive solar applications use building elements such as walls, windows, floor and roof in addition to exterior building elements. Landscaping can be used to control overheating by proving summer shade. Landscaping can also provide windbreaks for winter winds, and surfaces that can create sun pockets and reflect and reflective surfaces for winter sun.

Once the heat is collected inside, a well-insulated airtight building envelope helps prevent heat loss and allows the sun to provide more of the heat needed by the house.

At Canadian latitudes, proper design of exterior overhangs and shading devices can be optimized to get maximum sun penetration in winter, when it is needed most, and shade for most of the walls during the summer, when it is least wanted.

When retrofitting an existing home, some significant changes to window areas may be desired. Building code regulations for fire safety may restrict the amount of south side windows that can be used if the south side is near a property line.

Solariums are one of the most common and effective approaches to gaining solar energy in an existing home. They can be an attached solarium, or integrated into the existing structure. To reduce temperature swings, and uncomfortable overheating, the solarium should include reasonable thermal mass to store heat. This can be an insulated concrete floor slab with an exposed concrete or tile finish, a masonry feature wall, and even double thickness drywall. Water tanks are an excellent heat storage medium, and they can sometimes be incorporated into the design.

To be effective as a solar collector, the solarium should be treated as an area that can be closed off from the main living area at night. Even high performance insulating glass has heat loss, so the large solarium glass area can lead to an uncomfortably cool space on a cold night.

How Can Solar Energy Be Used?

How Can Solar Energy Be Used?

Knowing how we want to ue the energy will help determine the most effective manner of capturing the sun.

The first step in a solar retrofit is to list how energy is used in the home so that the most appropriate applications can be selected. The next step is to decide how much sun is available. The amount of solar energy available is dependent on time of year and location. In the winter the days are shorter and the sun is lower on the horizon, so the optimum collecting angle may vary. As one moves north the changes in the sun's position are more pronounced, so the position of solar energy collectors will differ based on latitude and time of year for which the system is optimized.

Southeast to southwest is the prime solar orientation. Determining how much sun is available can be done by looking at what obstructions there are on the south side of the house. Trees, other buildings or natural features that cast shadows must be evaluated to figure out if or when they will cause shading at various times of the year. Local geographical conditions that affect solar availability must also be taken into account. Rural or urban location will also have some bearing on appropriate solar options to harness.

Fiber Optics for Lighting

Fiber Optics for Lighting
ADLT has developed a unique dual compound parabolic collector (CPC) unit for fiber optic lighting systems. By channeling metal halide efficiency into fiber optic lighting systems, our CPC’s will produce more light, be much smaller (one-tenth the size) and more affordable than our competitors’ devices.
Combining this technology with Venture’s Uni-Form formed body quartz arc tubes, containing chemicals from APL and feature thin film optical coating similar to our telecommunications products results in an exciting new way of making fiber optic lighting. When we combine our compact dual CPC with a large core plastic optical fiber (LCPOF), it will result in a system with higher efficiency and a more even light distribution at the target.
Our new metal halide/fiber optic lighting system is the same cost as standard fiber optic systems, but uses only one-third the energy. To illustrate, a system powered by just one of our 68 watt metal halide lamps can replace six MR16 downlights (common in the retail industry). With these technological advances, our systems can compete with downlights, track lights, display case lighting and sign lighting (including neon).
ADLT’s optical fibers (or cables) can selectively emit light out the fiber side (like neon lighting) or transmit light to the fiber end using breakthrough polymer technology for superior light output, better color retention and high-quality light transmission. These solid core fibers for end and side lighting remain more flexible and durable over life; can be used for indoor and outdoor applications; multiple lighting from a single light source; are suitable for inaccessible or hazardous locations; have a high heat tolerance, and emit no infrared rays or ultraviolet light.
Plastic fibers, in general, depict colors more accurately, provide better overall light transmission and are more economical than glass fibers. Compared with stranded core plastic fibers, our solid core plastic fibers also give up to 30 percent more space through which light can travel and a 33 percent higher angle of acceptance. As a result, 76 percent more light will pass through solid core plastic fiber than stranded core.
Our fiber optics are made possible through partnerships with several of the world’s fiber optic leaders, including: Fiberstars, Inc., the world’s leading supplier of fiber optic lighting; Crescent Lighting, a United Kingdom-based state-of-the-art specialist in niche commercial lighting products; and Germany’s LBM. Unison’s legacy of product development and patented technologies benefits both Venture and Fiberstars. Unison was an ADLT/Rohm & Haas partnership transferred to Fiberstars during 2000.

ORNL hybrid lighting

ORNL hybrid lighting technology gaining momentum around nation

With five hybrid solar lighting systems already in place and another 20 scheduled to be installed in the next couple of months, the forecast is looking sunny for a technology developed at the Department of Energy's Oak Ridge National Laboratory.
Preliminary data from field units, which collect sunlight and pipe it into buildings using bundles of small optical fibers, show potentially significant energy savings in lighting and maintenance costs. An added benefit is that, for most uses, natural light is vastly superior to artificial light.

"This is the ultimate 'green' technology," said Duncan Earl, a co-developer of the technology and chief technology officer of Oak Ridge startup company Sunlight Direct, which licensed the technology from ORNL last year. "In fact, we have received many inquiries and are working with several organizations that are aiming to build LEED- (Leadership in Energy and Environmental Design) certified buildings." The U.S. Green Building Council established the LEED designation for buildings that comply with a national consensus standard for design and construction of "green" buildings. The hybrid solar lighting technology uses a rooftop-mounted 48-inch diameter collector and secondary mirror that track the sun throughout the day. The collector system focuses the sunlight into 127 optical fibers connected to hybrid light fixtures equipped with diffusion rods visually similar to fluorescent light bulbs. These rods spread light in all directions. One collector powers eight to 12 hybrid light fixtures, which can illuminate about 1,000 square feet. During times of little or no sunlight, a sensor controls the intensity of the artificial lamps to maintain a constant level of illumination.

NASA Lighting

Take the common incandescent bulb invented by Thomas Edison more than a century ago, or the type of fluorescent lamps first developed in the 1920s.
Both contain electrodes that burn out, so the lights must be periodically replaced. And both gobble up electrical power -- a precious commodity in space -- while generating heat, which must be dispelled from closed environments such as spaceships and space stations.
"Standard light sources that we use in homes and in greenhouses and in growth chambers for controlled agriculture here on Earth are not efficient enough for space travel. Not only that, they don't last a very long time," Goins said.
"And in space, heat is like trash. You make it, and you've got to get rid of it, so we don't want heat. We want light."
In recent years, dramatic improvements in lighting technology have provided NASA and its support contractors with new means to develop low-power space-farming systems that will last the life of a building -- or a greenhouse on the surface of Mars.
Working in plant growth chambers the size of walk-in refrigerators, Goins and other plant physiologists here are experimenting with blue and red Light Emitting Diodes, or LEDs, to grow salad plants such as lettuce and radishes.
Similar to devices now used to manufacture advanced traffic lights, the LEDs enable researchers to eliminate other wavelengths found within normal white light, thus reducing the amount of energy required to power the plant growth lamps.
The LEDs generate less heat, and while leaves take on a black hue due to the lack of green light to reflect, the plants grow normally and taste the same as those raised in white light.
"What we've found basically is that we are able to limit the amount of color we give to the plants and still have them grow as well as with white light," Goins said.
"Being plant physiologists, we know the chlorophyll molecule well enough that we know which wavelengths most efficiently stimulate plant growth, and it turns out to be blue and red. So I don't have to devote energy to green light, and my plant will grow just as well."
Nevertheless, green light can be added for aesthetic purposes.
"So if you're in orbit for a long time, not only do the plants taste good but they actually appear as plants do on the ground," Goins said. "But we also know we can eliminate the green light if energy costs are a concern -- and they usually are in space travel."
Another bonus: The LEDs can last the length of a round-trip mission to Mars, unlike incandescent or fluorescent bulbs, which require frequent replacement.
A second long-lasting light source being tested here: Sulfur Microwave Lamps.
Now used to light up large airplane hangars, shopping malls and gymnasiums, these high-performance lamps were first developed in 1991 and one day might be used to light conservatories on the surface of Mars. "The microwave lamp is a technology where we're thinking about a large-scale system like a greenhouse on Mars, where we can illuminate a large growth area," Goins said. "It is the most efficient electric lighting source known to man."
Twice as efficient as other high-intensity sources, the microwave lamps can generate as much light as the noonday sun. The light in fact is so bright that it can be funneled through pipes and then distributed over large areas, such as a hothouse on the Martian highlands.
The lamps also are dimmable, so space colonists would be able to attenuate light within their greenhouse to match the growing cycles of their crops.
"When there are small seedlings, you don't want a very bright light," Goins said. "But then you could turn the lamps up accordingly as the plants got bigger."
The bulbs, meanwhile, are simple hollow quartz spheres with sulfur and argon gasses that are energized with microwaves. And with no filament to burn out, researchers think the lamps could prove to be the perfect light source for a space colony.
"Theoretically, the microwave lamps should last for years and years, and we've found that to be the case," Goins said.
With an investment of just $80,000 to $100,000 over the past three years, the high-tech lighting systems here have been used to grow potatoes, sweet potatoes, lettuce, spinach, radishes, wheat onion and a whole plethora of herbs such as marjoram and parsley.
The plants typically are grown hydroponically, or without soil. Water laced with a nutrient solution is circulated within plant growth chambers that are lit up with either the LEDs or the Sulfur Microwave Lamps.
And while greenhouses and space colonies on Mars are still a long way off, Goins said a specially designed LED plant growth chamber should be ready for launch to the international station within the next three years.
"I would probably call it a salad machine," Goins said.
About half the size of a tall file cabinet, the plant growth chamber would enable station astronauts and cosmonauts to grow and harvest salad greens, herbs and vegetables during typical four-month tours on the outpost.
"Now this salad machine wouldn't be built on a scale large enough to actually give the crew all the food they need," Goins said. "It would be just a supplemental endeavor in the near term."
But it would have psychological benefits for station crews, too.
"When you're inside a can for several months, I can see where having something green and living onboard would be very appealing," Goins said.
"So to have an herb garden or a salad machine actually on the space station would make the stays in space more pleasurable," he added. They would just love that."

Advanced lighting technologies

Advanced lighting technologies enhance resident careResearch by a preeminent technical institute points the way toward more acceptable alternatives

Light, or the lack thereof, plays a role in the quality of care and safety experienced by residents in nursing homes and assisted living facilities, especially during nighttime hours. For example, an overhead light turned on at night during a check on a resident can be glaring and disruptive to sleeping residents. Conversely, a nightly trip to the bathroom can be difficult for residents making their way in the dark, increasing the risk of falls and injuries.New options and advancements in lighting technology, however, are showing promise in applications designed for increased safety and enhanced care in long-term care facilities. A recent study conducted by the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute in Troy, New York, showed just how well innovative lighting solutions can work for residents and staff. Mariana Figueiro, PhD, an LRC light and health specialist who has researched lighting designs and treatments for the elderly and those with Alzheimer’s disease, says, “For seniors, we know that as vision deteriorates, it becomes harder for the eyes to adapt to both dark environments and rapid changes in brightness.” These common vision difficulties led Dr. Figueiro and an LRC research team to conduct a pilot lighting demonstration study at Schuyler Ridge Residential Health Care, a 120-resident skilled nursing facility in Clifton Park, New York. (The facility is part of Seton Health, a comprehensive, integrated healthcare system anchored by St. Mary’s Hospital in nearby Troy.) The intent was to identify useful, energy-efficient lighting solutions that could improve the comfort and care of seniors and assist the nursing staff in their nightly rounds.Among the new technologies available, light-emitting diodes, or LEDs, show the most promise for use in unique and custom lighting designs. Unlike traditional incandescent lightbulbs, LEDs are tiny semiconductor chips that emit light in a range of vivid colors. LEDs have been used for decades as indicator lights in electronics and, more recently, in traffic signals, exit signs, and automobile taillights. According to Nadarajah Narendran, PhD, LRC director of research and organizer of the Alliance for Solid-State Illumination Systems and Technologies (ASSIST), the sponsor of the Schuyler Ridge pilot study, recent advancements have improved LEDs’ brightness and efficiency, allowing them to be used for still more lighting purposes. They also operate 40 to 50 times longer than traditional incandescent lamps, increasing their cost-effectiveness over time.In the long-term care facility, Dr. Narendran says, LEDs can offer many advantages for residents and staff, such as more acceptable night-lighting and emergency signaling. LEDs also can be configured to work during a power outage

NEW LIGHTING TECHNOLOGY: TINY SOURCE THAT LASTS UP TO 22 YEARS

NEW LIGHTING TECHNOLOGY: TINY SOURCE THAT LASTS UP TO 22 YEARS
01/03/2002
SAN JOSE, CA -- Lumileds Lighting has introduced a groundbreaking new lighting technology called Luxeon™ that gives lighting designers the ability to create a new breed of fixtures with tiny light sources that don’t need to be replaced for decades.
The Luxeon Power Light Source family consists of Light Emitting Diodes (LEDs) that have been specially engineered to match the brightness of traditional lighting. Using patented technology that makes it possible to enlarge the LED chip for more light output while maintaining proper heat and current management, Luxeon LEDs are able generate 10 to 20 times more light than standard indicator lights. This makes LEDs a practical illumination source for lighting fixtures for the first time.
For lighting designers, this means:
New design possibilities -- Since Luxeon LEDs are a fraction of the size of incandescent and halogen light sources, designers can create lighting solutions that are smaller, sleeker and lighter in weight than ever before. That can mean new silhouettes, invisible light points, and the ability to shrink the size of the optical lens.
‘Permanent’ bulbs -- A Luxeon device will last up to 100,000 hours compared to 1,000 to 2,000 hours for a typical incandescent bulb — long enough to last for 22 years in virtually any general lighting product, based on average operation of 12 hours per day. As a result, the light source can be integrated directly into the fixture without worrying about lamp replacement. Just fit it and forget it.
Energy savings -- Luxeon is more energy-efficient than incandescent and many halogen lamps. This stems from low power consumption as well as Luxeon ’s ability to produce 20 lumens per watt in white and as much as 50 lumens per watt in color — far surpassing an incandescent bulb in efficiency. Those efficiencies are continually climbing, with significant advances expected to hit the market in 2002.
Environmental soundness -- Because it is based on LED technology, Luxeon contains no mercury, thereby avoiding potential health hazards inherent in light sources like fluorescent lamps. The long life of a Luxeon device also eliminates waste and disposal problems that can take a toll on the environment.
High light output -- Luxeon can generate up to 324 lumens of white light, as much as 792 lumens of red light, and comparable brightness in other colors, depending on the number of Luxeon LEDS in the array configuration purchased. This output — the highest in the industry for LEDs — continues to rise through ongoing R&D.
White and color options-- Luxeon is available in white as well as green, blue, cyan, red, red-orange and amber.

Dimming con't

Whether you're looking for a romantic setting or just a place to unwind after a hard day's work, dimming the lights can have a lovely effect on a room. Your tranquility won't last long, though, if your dimmer switch causes your fixture to emit an audible hum or buzz.
Not all dimmers cause a buzz, but when they do they can be a pain. Understanding why it happens is your first step in choosing your strategy to eliminate it.
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It may look as though a dimmer simply reduces the amount of light produced by your lamp, but that's not what's happening. Although what your eye perceives is less light, a dimmer switch is actually turning the light on and off extremely fast — up to 120 times per second. So your lamp is producing the same amount of light, but for less time. The effect on your eye — and your mood — is that of dim light.
That on-and-off cycling can cause the filament in the light bulb to vibrate, causing an audible buzz. There are a couple of ways to eliminate the noise:
Change your light bulbs. If your fixture now has standard incandescent bulbs in it, try changing to "rough service bulbs" (the ones sold for refrigerators and garage door openers and the like). Rough service bulbs have sturdier supports for the filaments, and they'll vibrate less.
Lower your wattage. Dimmer switches are rated by how many watts they can control, and a 500-watt dimmer may start to struggle when the total wattage approaches that number. Putting lower-wattage bulbs in the fixture will ease the load and may stop the buzz.
Upgrade your dimmer. High-end dimmer switches include internal devices to absorb some of the jolts produced by the on-and-off cycles; inexpensive switches usually don't.
Install a lamp-debuzzing coil in the lighting circuit. An LDC wired in series with the dimmer helps regulate the flow of electricity and evens out the buzz-producing cycles. Then just sit back, dim the lights, and enjoy the silence.

Dimming lights with built-in transformers

Dimming lights with built-in transformers
Fully loaded halogen transformers usually dim quite well. If you are planning to dim halogen light transformers, try only dim traditional transformes, because toroidal core transformer do not usully dim well. Most of the cheap halogen light transformers belong to this category as well as the transformer in for example PAR36 pinspot lights. For this kind of transformer it is necessary that the current after the dimmer is still symmetric, so that there is no DC component formed to the transformer which can cause the transformer cire to aturate (and lead to overload and finaly destruction of transformer). Some of the cheapest light dimmers might not be very good on symmetry, but good quality light dimmers designed for also inductive loads should not have symmetry problems.
When dimming transformers with in any way questionable type do dimmer for inductive loads, it is a good idea to put a fuse in series with the transformer primary so that it will blow when transfromer tries to get too much power from the line. This will protect the transformer from overheating which might be caused because of transformer core saturation (which might be caused by small DC bias caused by not very well operating dimmer). A proper fuse will save transformers from burning out.
Anyway a normal transformers which feed light loads are dimmable with good quality dimmer which can handle at least some amount of inductive load usually without much problems. Anyway it should be mentioned that when a transformer is dimmed in this way, it can heat somewhat more than in normal operation (full power without dimming). Other thing worth to mention is that when a tranformer is dimmed, it usually produces noticably more audible noise than in normal operation (noise depends on used transformer).
If your halogen light system uses an electronic transformer then you must very carefully check if it can be dimmed. Some of the electronic transformers are made dimmable and work well with traditional light dimmers. The ones which are not ment to be dimmed can be damaged by the dimming and even damage your dimmer.

Dimming inductive loads

Normal light dimmers are designed to only dim non-lunductive loads like light bulbs and electric heaters. Normal light dimmers are not suitable to dim inductive loads like transformers, fluorescent lamps, neon lamps, halogen lamps with transformers and electric motors. There are special dimmers available for those applications.
If you connect inductive loads to the dimmer the dimmer might not work as expected (for example does not dim that load properly) and can even be damaged by the voltage surges generated by the inductive load when current changed radiply. Another problem is the phase shift between the voltage and current cause by the inductance. If you use a normal simple light dimmer which is just in series with the wire going to the load, this will cause that the dimmer circuit will not wirk properly with highly inductive loads. Special dimmers which have a separate controlling electronics connected to both live and neutral wire and then the triac which controls the current to the load usually work much bettter with inductive loads.
Often when inductive loads cause problems on normal dimmers, you can eliminate said problems by patching an incandescent "ballast" load in parallel with the inductive load. Usually 100W is enough for many inductive loads. Remeber that indictive loads can hum quite noticably when dimmed and the transformers can heat more because of increased harmonics content in the power coming to them.

Now can I dim up the lights smoothly ?

Now can I dim up the lights smoothly ?
With many cheap dimmers, the lights "Pop On" rather than dim up smoothly. This problem is usually related to the construction of the dimmer electronics. One technique used in some cheap dimmers to allow dimming up smoothly is to place another potentiometer (trimmer) across the control potentiometer. That trimmer potentiometer is set so that the dimmer works smoothly:
a)Set "Control" to Minimum light level.
b)Adjust "Trimmer" to filaments JUST "glow"
c)Turn off dimmer
d)Turn on dimmer to see if filaments "glow". IF not... set trimmer up a snit.... go to c) Continue until minimum voltage/current is supplied to lamps (filaments do not seem to glow at all). When everything is properly adjusted, the dimmer circuit will nicely dim up from the lowest setting up to maximum brightness.

Why does dimmed lighting sometimes hum, and how can it be corrected?

Why does dimmed lighting sometimes hum, and how can it be corrected?
Because of the way all dimmers deliver power at settings other than full brightness, the filaments inside a light bulb may vibrate when lighting is dimmed. This filament vibration causes the hum. To silence the fixture, a slight change in the brightness setting will usually eliminate bulb noise. The most effective way to quiet the fixture is to replace the light bulb.
How can I avoid the buzzing the dimmers cause to my sound system ?
There are numerous ways that dimmer noise can get into audio systems and it's largely trial and error in determining what in particular is causing your problem and hence how to fix it. The principle ways are either back up the mains or induced into your audio equipment or cables.
What you hear typically in audio system is common mode noise on the hot and neutral, the spike of turn-on of the scr. The higher the rise time of the current in the dimmer, more noise is sent to the mains wiring. So well filtered dimmer will generate less noise problems.
Reduce the possibility of it coming up the mains by taking a totally separate mains supply from the lighting, if possible get a totally separate power socket (or sockets) run in for sound from wherever the electricity board intake is. If this is not possible, then an isolation transformer stops quite much of the noise on the secondary side (better with shield between coils). So put the sound system on the isolation transformer and tie to earth (ground) almost no problems. This assume that sound wiring is correct, especially shielding is done well and ground loop are avoided.
To reduce the possibility of interference induced to the audio cables, run all non speaker level audio cables as balanced lines (or certainly all of any length). You might have to buy balancing transformers if your kit isn't balanced already. Also keep them as far away physically from any lighting cable runs as you can. Make sure that your system does hot have any harmful ground loops. Make sure none of your audio kit is anywhere near the dimmer racks.

Buzzing problems with dimmers

Buzzing problems with dimmers
Each good dimmer has a filter choke inside. Those chokes help to filter out electrical noise that often causes hum to be picked up in sound system and musical instrument pick-ups. The slower the current rise is, the less noise is picked by sound system.
The chokes also help to eliminate 'lamp singing' that can cause audible noise to come from the lighting fixtures. Lamps with power rating of 300W or more tend to more or less acoustic noise when dimmed. If this acoustic noise is a problem can be removed by adding a series coil which limits the current rise time to around 1 millisecond.
In providing those filtering functions, the chokes themselves can generate a slight buzz. Fast current changes in the coil can make the coil wiring and core material easily vibrate which causes buzzing noise. A little bit of buzzing is normal with filtered dimmers. If the buzz from dimmer can be a problem it is recommended that the dimmer is placed in the area where this buzz will not be a problem.
As far as the 'bulb singing' concerned, a bulb consists of a series of supports and, essentially, fine coils of wire. When the amount of current flow abruptly changes the magnetism change can be much stronger than it is on a simple sine wave. Hence, the filaments of the bulb will tend to vibrate more with a dimmer chopping up the wave form, and when the filaments vibrate against their support posts, you will get a buzz. If you have buzzing, it's always worth trying to replace the bulb with a different brand. Some cheap bulb brands have inadequate filament support, and simply changing to a different brand may help.
Buzzing bulbs are usually a sign of a "cheap" dimmer. Dimmers are supposed to have filters in them. The filter's job is to "round off" the sharp corners in the chopped waveform, thereby reducing EMI, and the abrupt current jumps that can cause buzzing. In cheap dimmers, they've economized on the manufacturing costs by cost-reducing the filtering, making it less effective.
In very high power dimming systems the wiring going to lighting can also cause buzzing. The fast current makes the electrical wiring to vibrate a little bit and if the wire is installed so that the vibration can be transferred to some other material then the buzzing could be heard. The buzzing caused by the vibration of the wiring is only problem in very high power systems like theatrical lighting with few kW of lights connected to the same cable. Better filtered dimmers can reduce the problem because the filter makes the current changes slower so the wires make less noise.

Power harmonics caused by dimmers

Power harmonics caused by dimmers
All phase control dimmers are non-linear loads. A non-linear load is one where current is not in proportion to voltage. The non-linear load on dimming systems is caused by the fact that current is switched on for only part of the line cycle by a phase control dimming system. This non-linear load creates harmonic distortion on the service feeder.
Harmonics are currents that occur at multiples of the power line voltage frequency. In Europe where line frequency is 50 Hz the 2nd harmonic frequency is 100 Hz; the 3rd harmonic is 150 Hz, and so on. In North America where line frequency is 60 Hz the 2nd harmonic frequency is 120 Hz; the 3rd harmonic is 180 Hz, and so on.
Excess harmonic currents cause conductors and the steel cores of transformers and motors to heat. Odd-order harmonic currents (specifically the 3rd harmonic) add together in the neutral conductor of 3 phase power distribution systems. The 3rd order harmonic current present on the neutral is the arithmetic sum of the harmonic current present on the three phase conductors (this also applies to the 9th, the 15th and so on harmonics). Harmonics could theoretically elevate the neutral current to 3.0 times what is present on a phase conductor. With typical phase control dimming system connected to three pahse feed, the harmonics normally elevate neutral current to about 1.37 times phase current. If the wires are not properly rated for this, neutral conductor overheating or unexplained voltage drops can occur in large dimming systems.
Sometimes the heating of the distribution trasformer can be a problem, because transformers are rated for undistorted 50 Hz or 60 Hz load currents. When load currents are non-linear and have substantial harmonic content, they cause considerably more heating than the same undistorted current. In heavily dimmed system, you might not be able to ultilize more than around 70 % of the rated transformer power rating because of harmonic induced heating. Additionally, transformers used to feed dimming systems are subjected to stress because of cold lamp inrush currents (can be up to 25 times normal current). Inrush currents and harmonics can drastically reduce the service life of the service transformer.
Eliminating the effects of harmonic currents in large light dimmer systems normally requires oversizing neutral conductors and derating the service transformer.
In a normal low power light dimmer case you don't have to woryr much about the harmonics and transformer loads, because the light load of few hundred watts is clearly just a small fraction of the total transformer load.

Radio frequency interference details

Radio frequency interference details
The modern thyristor (Triac or SCR) dimmer has one fairly severe drawback in its performance in that it dims by switching on the current to the load part-way through each mains cycle. Cutting the leading smooth-part off a mains cycle produces a current with a very rapid turn-on time which generates both mains distortions and EMI. Chokes are included in dimmers to slow down the rapid switch-on (rise time) of the chopped current. The longer the rise time the less EMI and mains distortion produced.
Turn on of the triac in the middle of the phase causes fast voltage and current changes. A typical thyristor/triac starts to fully conduct at around 1 microsecond time after triggering, so the current change is very fast if it not limited in any way. Those fast voltage and current changes cause high frequency interference going to mains wiring unless there are suitable radio frequency interference (RFI) filter built into the circuit. The corners in the waveform effectively consist of 50/60Hz plus varying amounts of other frequencies that are multiples of 50/60Hz. In some cases the interference goes up to 1..10Mhz frequencies and even higher. The wiring in your house acts as an antenna and essentially broadcasts it into the air. Cheap bad quality light dimmers don't have adequate filtering and they cause easily lots of radio interference.
Dimmer circuits typically use coils that limit limit the rate of rise of current to that value which would result in acceptable EMI. Typical filtering in light dimmers causes the current rise time (current rises from 10% to 90%) to be in range of 30..50 microseconds. This gives acceptable results in typical dimmer applications in home (typically this limitation is made using 40..100 uH coil).
If the dimmers are used in places where dimmer is a serious problem for sensitive sound equipments (theatres, TV-studios, rock concerts etc.) a slower current rise time would be preferred. Typically the current rise time in light dimmer packs made for stage applications have a current rise speed of around 100..350 microseconds. If noise is a big problem (TV studios etc.), even slower current rise times are sometimes asked. Those current rise times up to 1 millisecond can be achieved with special dimmers or suitable extra coil fitted in series with the dimmer.
The coil itself does not typically solve the whole problem because of the self-capacitance of the inductor: they typically resonate below 200 kHz and look like capacitors to disturbances above the resonance frequency. That's why there must be also capacitors to suppress the interference at higher frequencies.
If your dimmer circuit cause interference, you can try to filter out the interference by adding a small capacitor (typically 22nF to 47 nF) in parallel with the dimmer circuit as near as possible to the electronics inside the circuit as possible. Keep in mind to use a capacitor which is rated for this kind of applications (use capacitors marked with X). Keep in mind that the filter capacitor and it's wiring make a resonance circuit with certain resonance frequency (typically around 3.6 MHz with 0.1 uF capacitor). The capacitor does not work well as filter with the frequencies higher than the resonance frequency of the circuit.

Incandescent lamp physics

Incandescent lamp physics
A typical incandescent lamp take power and uses it to heat up a filament until it will start to radiate light. In the process about 10% of the energy is converted to visible light. When the lamp is first turned on, the resistance of the cold filament can be 29 times lower than it's warm resistance. This characteristic is good in terms of quick warmup times, but it means that even 20 times the steady-state current will be drawn for the first few milliseconds of operation. Lamp manufacturers quote a typical figure for cold lamp resistance of 1/17 th of the operational resistance, although inrush currents are generally only ten times the operational current when such things as cable and supply impedance are taken into account. The semiconductors, wiring, and fusing of the dimmer must be designed with this inrush current in mind. The inrush current characteristic of incandescent (tungsten filament) lamps is somewhat similar to the surge characteristic of the typical thyristors made for power controlling, making them a quite good match. The typical ten times steady state ratings which apply to both from a cold start allow many triacs to switch lamps with current ratings close to their own steady state ratings.
Because lamp filament has a finite mass, it take some time (depending on lamp size) to reach the operating temperature and give full light output. This delay is perceived as a "lag", and limtis how quicly effect lighting can be dimmed up. In theatrical application those problems are reduced using preheat (small current flows through lamp to keep it warm when it is dimmed out).
The ideal lamp would produce 50% light output at 50% power input. Unfortunately, incandescents aren't even close that. Most require at least 15% power to come on at all, and afterwards increase in intensity at an exponential rate.
To make thing even more complicated, the human eye perceives light intensity as a sort of inverse-log curve. The relation of the the phase control value (triac turn on delay after zero cross) and the power applied to the light bulb is very non-linear. To get around those problems, most theatrical light dimmer manufacturers incorporate proprietary intensity curves in their control circuits to attempt to make selected intensity more closely approximate perceived intensity.

How modern light dimmers work

How modern light dimmers work ?
Solid-state light dimmers work by varying the "duty cycle" (on/off time) of the full AC voltage that is applied to the lights being controlled. For example, if the voltage is applied for only half of each AC cycle, the light bulb will appear to be much less bright than when it get the full AC voltage, because it get's less power to heat the filament. Solid-state dimmers use the brightness knob setting to determine at what point in each voltage cycle to switch the light on and off.
Typical light dimmers are built using thyristors and the exact time when the thyristor is triggered relative to the zero crossings of the AC power is used to determine the power level. When the the thyristor is triggered it keeps conducting until the current passing though it goes to zero (exactly at the next zero crossing if the load is purely resistive, like light bulb). By changing the phase at which you trigger the triac you change the duty cycle and therefore the brightness of the light.
The advantage of thyristors over simple variable resistors is that they (ideally) dissipate very little power as they are either fully on or fully off. Typically thyristor causes voltage drop of 1-1.5 V when it passes the load current.
What are thyristors and triacs
A Silicon Controlled Rectifier is one type of thyrister used where the power to be controlled is unidirectional. The Triac is a thyrister used where AC power is to be controlled.
Both types are normally off but may be triggered on by a low current pulse to an input called the gate. Once triggered on, they remain on until the current flowing through the main terminals of the device goes to zero.
Both SCRs and Triacs are 4 layer PNPN structures. The usual way an SCR is described is with an analogy to a pair of cross connected transistors - one is NPN and the other is PNP. +------+
If we connect the positive terminal of a supply to say, a light bulb, and then to the emitter of the PNP transistor and its return to the emitter of the NPN transistor, no current will flow as long as the breakdown voltage ratings of the transistor are not exceeded because there is no base current to either.
However, if we provide some current to the base of the NPN (IG(+)) transistor, it will turn on and provide current to the base of the PNP transistor which will turn on providing more current to the NPN transistor. The entire structure is now in the on state and will stay that way even when the input to the NPN's base is removed until the power supply goes to 0 and the load current goes to 0.
The same scenario is true if we reverse the power supply and use the IG(-) input for the trigger.
A Triac works basically in a similar manner but the polarity of the Gate can be either + or - during either half cycle of an AC source. Typically the trigger signals used for triggering triacs are short pulses.

ENERGY STAR

Make your next light an ENERGY STAR®. Light fixtures and torchieres that have earned the ENERGY STAR logo combine high performance, attractive design, and highest levels of energy efficiency.
Benefits
All ENERGY STAR qualified indoor fixtures come with pin-based CFLs which use 66 per cent less electricity than standard incandescent bulbs and last up to 10 times longer.
ENERGY STAR qualified torchiere lamps use bulbs that are cool to the touch. Typical halogen torchiere floor lamps can burn dangerously hot – up to 1,100ºF.
ENERGY STAR qualified light fixtures and CFLs carry a two year warranty - double the industry standard.
Where to install
ENERGY STAR qualified light fixtures and CFLs are ideal for places you need light for several hours at a time. Frequent switching on and off can shorten the CFL’s life.
ENERGY STAR qualified light fixtures and CFLs are perfect for hard to reach places because you don’t need to replace the bulbs as often.
ENERGY STAR qualified light fixtures and CFLs are great for front porches. Check the bulb’s packaging for the minimum starting temperature.
What is a torchiere?
A torchiere is a portable lamp designed to direct light upward for indirect illumination. Most of the light is thrown against the ceiling and reflected back.
A Compact Fluorescent torchiere uses a fluorescent lamp, typically a circular or D-shaped compact. Torchieres that use halogen lamps are more common in homes. Halogen torchieres typically use 300-watt bulbs which can become fire hazards due to the extremely high temperatures that they reach. Since halogen bulbs cannot be substituted with CFLs, entire halogen lamps will have to be replaced.
Compact fluorescent torchieres use approximately 70% less energy than halogen torchieres to produce the same amount of light.
Compact fluorescent bulbs last approximately five times longer than halogen bulbs.
Replacing a 200-watt halogen torchiere with a 55-watt compact fluorescent torchiere will save approximately $100 in electricity over the life of the compact fluorescent bulb.
Being more efficient, fluorescent lighting gives off much less heat than halogen lighting, making the compact fluorescent torchiere a safer light source.
Like halogen torchieres, compact fluorescent torchieres come in a variety of styles including dimmable or three-level lighting. Check the packaging to make sure you are buying the correct style for your needs.

Transient Voltages

Introduction
Protecting computer equipment can be confusing. There are many options in the marketplace,
not all of which will provide complete protection. This brochure is designed to help
define the best protection for your application. Transient Voltage Surge Suppression (or
TVSS) technologies protect microprocessor operations from damage due to switching surges
or surges associated with events like power outages.
Surge disturbances are very short-duration, high-magnitude voltage fluctuations. Because of
their short duration, they may not exhibit any immediately perceptible impact. They can be
caused by any switching operation on the electrical system (mechanical or electrical).
Surge damage can be: immediate, manifesting as failure, or cumulative, manifesting as
failure over time due to a weakened state. Surges can also cause data upset, occuring as
temporary malfunctions or system glitches that result in lost production, data or time.
TVSS devices are designed to keep harmful surge energy away from sensitive electronic
equipment. A TVSS device accomplishes this by diverting this energy to a path away from
critical equipment.
An investment in sensitive electronic equipment (stereos, televisions, appliances, computers
and control systems) can be significant. A properly specified TVSS device is cost-effective
insurance for this investment.
This brochure will walk you through the information you will need to know to select the
TVSS device for your application.

TVSS applications
TVSS devices can be installed individually for basic protection or they can be installed in a
network, designed to provide maximum benefit for a given electrical system. To determine
the best approach for your application, it is important to understand the different methods
of installation.
TVSS installation locations
When TVSS devices are installed at multiple locations, make sure that the clamping voltage and energy handling capability are correctly matched for the application. As shown in the diagram, the clamping level should be lower and the energy handling capability greater for the panelboard-mounted devicethan would be for an outletinstalled
device.

Hardwired TVSS devices are permanently installed by electricians at circuit breaker panels, transformers or main service switchgear. The intent of this application is to provide protection to several pieces of equipment. A TVSS installed at the service panel will provide protection for all “downstream” electrical components from all “upstream” surge disturbances.

Solar Photovoltaic

Solar photovoltaic (PV) technology is the direct conversion of sunlight into electricity by solid-state semi-conductor diodes called photovoltaic cells. Silicon is the most common semi-conducting material used to make photovoltaic cells.
A single photovoltaic cell produces only a few watts, so solar photovoltaic modules are comprised of several photovoltaic cells laminated into a single unit. The voltage of the photovoltaic module depends on the number of cells connected in series, and the current is proportional to the surface area of the photovoltaic cells.
The most common solar module technology uses 200 to 300 mm thick wafers of
crystalline silicon (c-Si) or multi-crystalline silicon (mc-Si), similar to the wafers used to manufacture integrated circuits. The manufacturing process for crystalline silicon solar modules consists of several steps including manufacture and testing of the cells, electrical interconnection of the cells and laminating them into a complete module.
Amorphous silicon (a-Si) is another photovoltaic technology that is gaining broad
acceptance. Amorphous silicon is less efficient than crystalline technologies, but it has the advantage of using much less silicon. Amorphous silicon cells are deposited on a substrate such as glass or steel and are only 2 or 3 mm thick. Thin film technologies such as amorphous silicon hold the potential for low cost mass-produced solar modules. Other thin film technologies have been commercialized for outdoor terrestrial applications in the past few years. These photovoltaic modules use semi-conductors such as Cadmium Telluride (CdTe), Cadmium Sulfide (CdS) and Copper Indium Diselenide(CIS). These technologies promise greater efficiencies than amorphous silicon but are still in the early stages of commercialization. [1]
Industry practice is to rate photovoltaic modules at Standard Test Conditions (STC). Thepower rating obtained at STC, is often referred to as the peak power of the module and is measured in peak watts (Wpeak). This rating is useful for comparing one module to another, but does not reflect the actual performance of a photovoltaic module in the field.