EARTHLIGHT AT NIGHT – shows the whole planet at night and illustrates interesting urban and transportation patterns as illuminated by human-made lights: the scarcity of lights for North vs. South Korea, the ribbon of lights along the Nile, the township and range of the U.S. high plains grid, and the life line of lights along the Trans-Siberian Railroad in Russia. Poster version with activities from “Mission Geography” (http://missiongeography.org/) available.
2019-03-31. LightTrends is a light pollution web application (https://lighttrends.lightpollutionmap.info) that allows you to examine changes in nighttime light emissions (nearly) worldwide, from 1992 up until last month.
2017-01-10. The Lights Are On in Detroit. By Michael Kimmelmanjan, The New York Times. Excerpt: DETROIT — Just before the holidays, on a dark street a few blocks from downtown, a group of public officials crowded onto a makeshift stage before a shivering crowd, flipped a big switch — and the last of this city’s 65,000 new streetlights blazed on. …Investments by the Obama administration in energy-efficient lighting have reduced costs, making LEDs feasible for a city like Detroit. Three years ago, nearly half the 88,000 streetlights in the city were out of commission. The more potent LED lights allow the authority to replace those 88,000 old fixtures with 65,000 new ones, strong enough for you to read one of those glossy magazines after dark. The whole thing came in under budget and on time. …“An example of how good government should work,” as Lorna L. Thomas, chairwoman of the lighting authority, put it at the switch-flipping ceremony…. https://www.nytimes.com/2017/01/10/arts/the-lights-are-on-in-detroit.html
2014-10-07. Invention of Blue LEDs Wins Physics Nobel. By Jonathan Webb, BBC News. Excerpt: [T]he first blue LEDs in the early 1990s …enabled a new generation of bright, energy-efficient white lamps, as well as colour LED screens. …Nobel Prizes were established to recognise developments that delivered “the greatest benefit to mankind”. …Although red and green LEDs had been around for many years, blue LEDs were a long-standing challenge for scientists in both academia and industry. Without them, the three colours could not be mixed to produce the white light we now see in LED-based computer and TV screens. Furthermore, the high-energy blue light could be used to excite phosphorus and directly produce white light – the basis of the next generation of light bulb. …White LED lamps…use much less energy than both incandescent and fluorescent lamps. That improvement arises because LEDs convert electricity directly into photons of light, instead of the wasteful mixture of heat and light generated inside traditional, incandescent bulbs. …Commenting on the news, the president of the Institute of Physics, Dr Frances Saunders, emphasised that energy-efficient lamps form an important part of the effort to help slow carbon dioxide emissions worldwide. “With 20% of the world’s electricity used for lighting, it’s been calculated that optimal use of LED lighting could reduce this to 4%,” she said. …LED lamps have the potential to help more than 1.5 billion people around the world who do not have access to electricity grids – because they are efficient enough to run on cheap, local solar power. …”It pleases me greatly, because this is good science but it’s also useful science. It’s making a huge difference to energy savings.”… http://www.bbc.com/news/science-environment-29518521. By Jonathan Webb, BBC News. See also http://www.nytimes.com/2014/10/08/science/isamu-akasaki-hiroshi-amano-and-shuji-nakamura-awarded-the-nobel-prize-in-physics.html
2013-12-31. The End Of The Bulb As We Know It? Not Quite. Excerpt: January 1 is the end of the era of your standard, soft white Edison-designed incandescent bulb in the United States. Or at least, in theory. …loopholes in the law will make the incandescent still widely available — if you really want it. Bruce Cudmore, the purchasing manager at Carr Sales & Lighting Center in Spokane, is down to his last few 40-watt bulbs…. Cudmore still has 100-watt bulbs for sale and those were eliminated on Jan. 1, 2012. …the law exempts what are known as rough service or vibration resistant incandescents… designed for machinery, but many stores plan to start carrying them for customers who demand that incandescent glow. Still, Cudmore encourages people to make the switch to the much more efficient compact fluorescent, LED or halogen bulbs. …Cudmore says you can avoid that unflattering blue tinge the curly bulbs are notorious for: Look for labels that say 2700 Kelvin, “warm white,” or “soft white.” The Energy Independence and Security Act ends production and import of 40-watt and 60-watt incandescent bulbs on Jan. 1, as it did with 75-watt bulbs in 2013 and 100-watt bulbs in 2012. Some specialty and low-watt incandescents are exempt from the law, including certain bulbs for recess lighting and flame-shaped candelabra bulbs…. http://earthfix.opb.org/energy/article/the-end-of-the-bulb-as-we-know-it-not-quite/. Oregon Public Broadcasting.
2012 Jan 24. Building A Better Bulb: Lighting Revolution Advances. By Dave Levitan, Yale Environment 360. Excerpt: Despite an outcry from U.S. conservatives that new lighting efficiency standards infringe on personal freedom, legislation mandating greater efficiency became law on January 1. Those new standards, along with major progress in lighting research and development, are helping usher in a technological revolution: Lighting companies — both large and small, in the U.S. and abroad — are rapidly building a better light bulb….
…The U.S. changes are long overdue. Efficiency standards for other technologies, such as refrigerators and washing machines, have been around since the Reagan Administration. With lighting accounting for around 15 percent of residential electricity use (and 35 percent in commercial buildings), phasing out the inefficient old bulbs represents a huge economic and environmental opportunity….
2011 Dec 16. Despite Delay, the 100-Watt Bulb Is on Its Way Out. By Diane Cardwell, The NY Times. Excerpt: The law to phase out traditional incandescent light bulbs was promoted as a simple, almost painless, change when Congress first passed it….But the traditional light bulb — that lowly orb of glass, filament and threaded metal base — has become a powerful emotional symbol, conjuring both consumer anxiety over losing a familiar and flattering light source and political antipathy to government meddling….
…Yet in some ways, despite all the heated rhetoric and political brinksmanship, the delay hardly matters. The looming possibility of the new standards…has transformed the industry. A host of more efficient products already line store shelves and poke out of light sockets….
2011 September 18. How water bottles create cheap lighting in Philippines. Video report by Kate McGeown, BBC. Video description: “A simple initiative in the Philippines is bringing a bit of brightness into the lives of the country’s poorest people.
The project is called “Litre of Light,” and the technology involved is just a plastic bottle filled with water.
It’s an environmentally-friendly alternative to an electric light bulb, and it’s virtually free.”
2010 January. Let There Be LEDs. Green Tips — Union of Concerned Scientists. Excerpt: Compact fluorescent lightbulbs (CFLs) … consuming 50 to 80 percent less electricity than traditional incandescent bulbs. But an even more efficient option is light-emitting diode (LED) bulbs, which… use a fraction of the electricity required by other light sources: a six-watt LED generates more light than an 11-watt CFL or 40-watt incandescent while using 45 percent less electricity than the CFL and 85 percent less than the incandescent….
LEDs offer other advantages as well:
Longevity. CFLs last about 10 times longer than incandescents (6,000 to 15,000 hours versus 1,000 to 2,000), but LEDs take the life-span prize, lasting 50,000 hours-nearly 23 years if used six hours per day-or more.
Safety. LEDs generate about 97 percent less heat than incandescent bulbs, making them a safer option for enclosed fixtures and for use on or near plants and flammable materials. And unlike CFLs, LEDs do not contain mercury (though the small amounts in CFLs do not pose a safety risk unless they are broken).
…Despite the advantages, two important factors have thus far kept LEDs from entering the mainstream:
Price. LEDs currently have a significantly higher up-front cost than CFLs-$35 for a six-watt LED versus $4 or less for an equivalent 11-watt CFL. While the LED would cost only $30 to operate over its 25-year lifetime compared with $55 for the CFL (based on a national average electricity cost of 10 cents per kilowatt-hour), outfitting your entire house with LEDs could be prohibitively expensive until costs come down….
2009 Nov 29. LED Bulbs Save Substantial Energy, a Study Finds. By Eric A. Taub, NY Times. Excerpt: Does the latest generation of energy-saving light bulbs save energy? A comprehensive study conducted by Osram, the German lighting company, provides evidence that they do.
…While that may seem self-evident, until the release of the report on Monday the answer remained unclear. …The study results show that over the entire life of the bulb – from manufacturing to disposal – the energy used for incandescent bulbs is almost five times that used for compact fluorescents and LED lamps.
The energy used during the manufacturing phase of all lamps is insignificant – less than 2 percent of the total. Given that both compact fluorescents and LEDs use about 20 percent of the electricity needed to create the same amount of light as a standard incandescent, both lighting technologies put incandescents to shame.
…Compact fluorescents also contain harmful mercury, which can pollute the soil when discarded….
2009 August 4. LEDs Are As Energy Efficient as Compact Fluorescents. By Eric A. Taub, The NY Times. Excerpt: While there’s no question that LED lamps use a fraction of the energy to produce the same amount of light compared with a standard incandescent bulb, several Bits readers have pointed out that that’s only half the story.
If the energy used to create and dispose of the LED lamp is more than that for a comparable standard bulb, then all of the proclaimed energy savings to produce light are for naught.
Until recently, no one knew if that was the case. In March, a preliminary study reported by Carnegie Mellon indicated that LED lamps were more energy efficient throughout their life, but the researchers pointed out that not every aspect of the production process was taken into account.
A new study released on Tuesday by Osram, the German lighting giant, claims to have confirmed the efficiency findings.
…the report examines the energy needed to create and power an LED lamp. Even the energy needed to ship a lamp from the factory in China to an installation in Europe was taken into account.
…The findings, according to a summary of the study: today’s LED lamps are essentially as energy efficient as compact fluorescents, in the amount of energy needed to create, recycle and provide light. Osram said it expected those numbers to improve as LEDs become more energy efficient….
2009 May 11. Industry Looks to LED Bulbs for the Home. By Eric A. Taub, NY Times. Lightfair International, the lighting industry’s annual trade show, showed off an abundance of LED bulbs for homes and workplaces.
2009 Mar 28. Earth Hour 2009. Before after photos of Earth Hour efforts around the globe.
2009 March 25. Let there be light-emitting diodes. By Erin Allday, SF Chronicle. Excerpt: No doubt, street lights enhancements are not the most thrilling policies to come out of City Hall. But the LED lights being installed in the Tenderloin are actually pretty neat.
…The LEDs are more energy efficient than traditional bulbs, so there’s an environmental angle (of course). But what’s cool about the lights isn’t so much the LED technology, which we’ve all seen before (they’ve been installed in many traffic signals, for starters), but the “smart controller” that’s also involved.
Mayor Gavin Newsom showed it off at a press conference on Wednesday when he turned on the Taylor Street lights by hitting a button on his iPhone. With the right password, the lights can be turned on and off from just about anywhere.
The lights can also be dimmed … and turned into strobes, which would be used to point police and fire personnel to the location of an emergency.
The LED lights will replace most street lights in phases over the next several years. Each light costs about $700, compared to about $150 for old-fashioned bulbs, but city officials note that they last at least four times longer and are 50 percent more energy efficient….
2008 June 22. The New Trophy Home, Small and Ecological By FELICITY BARRINGER. NY Times. Excerpt: For the high-profile crowd that turned out to celebrate a new home in Venice, Calif., the attraction wasn’t just the company and the architectural detail. The house boasted the builders’ equivalent of a three-star Michelin rating: a LEED platinum certificate. The actors John Cusack and Pierce Brosnan, with his wife, Keely Shaye Smith, a journalist, came last fall to see a house that the builders promised would “emit no harmful gases into the atmosphere,” “produce its own energy” and incorporate recycled materials, from concrete to countertops.
Behind the scenes were Tom Schey, a homebuilder in Santa Monica, and his business partner, Kelly Meyer, an environmentalist whose husband, Ron, is the president of Universal Studios. Ms. Meyer said their goal was to show that something energy-conscious “doesn’t have to look as if you got it off the bottom shelf of a health-food store.”
“It doesn’t have to smell like hemp,” she said.
That was probably a good thing. The four-bedroom house was for sale, with a $2.8 million asking price.
Its rating was built into that price. LEED – an acronym for Leadership in Energy and Environmental Design, is the hot designer label, and platinum is the badge of honor – the top classification given by the U.S. Green Building Council. “There’s kind of a green pride, like driving a Prius,” said Brenden McEneaney, a green building adviser to the city of Santa Monica, adding, “It’s spreading all over the place.”
Devised eight years ago for the commercial arena, the ratings now cover many things, including schools and retail interiors. But homes are the new frontier.
While other ratings are widely recognized, like the federal Energy Star for appliances, the LEED brand stands apart because of its four-level rankings – certified, silver, gold and platinum – and third-party verification.
…More than 1,500 commercial buildings and 684 homes have been certified but just 48 homes have received the platinum ranking, among them a four-bedroom home in Freeport, Me., as well as homes in Minneapolis; Callaway, Fla.; Dexter, Mich.; and Paterson, N.J.
2008 February. Let There Be (Fluorescent) Light. Union of Concerned Scientists. A provision in the 2007 energy bill requires lightbulbs to be 30 percent more energy-efficient starting in 2012-a standard that will effectively phase out traditional incandescent bulbs. But why wait? Today’s compact fluorescent light bulbs (CFLs) already use 50 to 80 percent less energy than incandescent bulbs. If every U.S. household replaced just one incandescent bulb with a CFL, the Environmental Protection Agency estimates we would reduce global warming pollution by an amount equivalent to taking more than 800,000 cars off the road.
…CFLs do contain a small amount of mercury, so they cannot be thrown out in the trash (see the related links for disposal information). However, the mercury in CFLs represents a much less significant environmental hazard than incandescent bulbs because CFLs require much less electricity, and more than half of our nation’s electricity is generated by coal-fired power plants-the largest U.S. source of mercury emissions.
In other words, the average coal-fired power plant emits only 3.2 milligrams of mercury for each CFL running six hours per day for five years, but emits nearly 15 milligrams of mercury for an incandescent bulb running the same amount of time, according to UCS research. The difference far exceeds the approximately five milligrams present inside a CFL. Properly disposing of CFLs ensures the mercury in them remains contained.
25 February 2008 – March 8 GLOBE at Night
Make simple observation of Orion and use simple magnitude charts to gauge quality of sky. Report observation to the GLOBE project. During the 2007 event there were 8,491 observations reported from 60 GLOBE countries, almost doubling the observations from 2006
November 2007. LED Lights Make Your Holiday Greener, Union of Concerned Scientists. Read this issue of Greentips online Twinkling lights on trees and houses are an icon of the holiday season, but their energy consumption might put a damper on your celebratory mood: this year’s holiday lights could generate as much global warming pollution as about 250,000 cars, according to UCS research. Most of this electricity is needlessly wasted, because the mini and C-7 incandescent lights used by most homeowners are only about 10 percent efficient.
There are a variety of ways to decorate the home without using electricity, but families who enjoy the look or tradition of holiday lights can save money and help protect the environment by switching to LED (light-emitting diode) holiday lights. LEDs employ semiconductor technology to convert electricity into light directly, resulting in significant energy savings. An LED uses approximately 0.04 watt of electricity, compared with 0.45 watt for a mini incandescent light bulb and 7 watts for a C-7 incandescent bulb.
LEDs provide several other benefits as well:
* Safety-LEDs stay cool to the touch, posing less of a fire hazard compared with incandescent lights. In addition, their low energy consumption allows you to connect up to 25 strands of lights end to end without overloading a circuit. * Durability-The small size and solid construction of LED bulbs make them less likely to break.
* Long Life-LED bulbs can last up to 100,000 hours or more, which is equivalent to more than 10 years of continuous indoor use. If a single bulb in an LED strand does happen to fail, the remaining bulbs will continue to work.
While they have a higher purchase price (they cost about two to three times more than incandescent lights), LED holiday lights quickly pay for themselves through energy savings. Using the national average residential rate of 11.06 cents per kilowatt-hour, it costs only 32 cents to use 300 LED lights for five hours per day for 45 days. In comparison, using incandescent mini lights or C-7 lights for the same amount of time would cost $3.36 and $52.25, respectively. This does not include replacement costs for incandescent light strands, which do not last as long as LED strands….
1 October 2007. The Great World Wide Star Count. … Roberta Johnson. Windows to the Universe is running a citizen science campaign beginning October 1 — the Great World Wide Star Count. This international event encourages everyone to go outside, look skywards after dark, count the stars they see in certain constellations, and report what they see online. This campaign is designed to raise awareness about the night sky and encourage learning of astronomy. All the information needed to participate will be available on the Star Count Web site. The Star Count uses a simple data collection procedure and an easy data entry form. At the conclusion of the event, the submitted data will be analyzed and a map will be generated highlighting the results of this exciting citizen science campaign. Mark your calendars and plan on joining thousands of other students, families, and citizen scientists counting stars this fall. The Great World Wide Star Count will be held from October 1st through October 15, 2007. For more information visit http://www.windows.ucar.edu/citizen_science/starcount.html or email email@example.com.
9 May 2007. BAN THE BULB: Worldwide Shift from Incandescents to Compact Fluorescents Could Close 270 Coal-Fired Power Plants. Earth Policy Institute. Eco-Economy Update. Lester R. Brown. Excerpt: On February 20, 2007, Australia announced it would phase out the sale of inefficient incandescent light bulbs by 2010, replacing them with highly efficient compact fluorescent bulbs that use one fourth as much electricity. If the rest of the world joins Australia in this simple step to sharply cut carbon emissions, the worldwide drop in electricity use would permit the closing of more than 270 coal-fired (500 megawatt) power plants. For the United States, this bulb switch would facilitate shutting down 80 coal-fired plants. …At the commercial level, Wal-Mart, the world’s largest retailer, announced a marketing campaign in November 2006 to boost its sales of compact fluorescents to 100 million by the end of 2007, more than doubling its annual sales. In the U.K., Currys, Britain’s largest electrical retail chain, has announced that it will discontinue selling incandescent light bulbs. …One disadvantage of compact fluorescents is that each bulb contains a small amount of mercury, roughly one fifth the amount in a watch battery. This mercury is only a small fraction of that released into the atmosphere by the additional coal burned to power an incandescent. Mercury released by coal-fired power plants is the principal reason why 44 of the 50 states in the United States have issued mercury intake advisories limiting the consumption of fish from freshwater streams and lakes. Nonetheless, worn-out compact fluorescents, watch batteries, and other items that contain mercury still need to be recycled properly. Fortunately, this is possible, whereas the mercury spewing from coal smokestacks blankets the countryside, ending up in the water and food supply.
20 February 2007. Australia to Ban Old-Style Light Bulbs. By ROHAN SULLIVAN, Associated Press Writer (02-20)Excerpt: 12:15 PST SYDNEY, Australia (AP) –The Australian government on Tuesday announced plans to phase out incandescent light bulbs and replace them with more energy-efficient compact fluorescent bulbs across the country. Legislation to gradually restrict the sale of the old-style bulbs could reduce Australia’s greenhouse gas emissions by 4 million tons by 2012 and cut household power bills by up to 66 percent, said Environment Minister Malcolm Turnbull. …Last month, a California assemblyman announced he would propose a bill to ban the use of incandescent bulbs in his state. And a New Jersey lawmaker has called for the state to switch to fluorescent lighting in government buildings within three years. Cuba’s Fidel Castro launched a similar program two years ago, sending youth brigades into homes and switching out regular bulbs for energy-saving ones to help battle electrical blackouts around the island. The idea was later embraced by Castro’s friend and ally, Venezuelan President Hugo Chavez, who announced his own program to save energy and in recent months has given away millions of fluorescent bulbs in neighborhoods nationwide…. https://www.seattletimes.com/nation-world/australia-to-ban-old-style-light-bulbs-go-fluorescent/
2 January 2007. Wal-Mart Puts Some Muscle Behind Power-Sipping Bulbs. The New York Times. By MICHAEL BARBARO Excerpt: …it turns out that thelong-lasting, swirl-shaped light bulbs known as compact fluorescent lampsare to the nation’s energy problem what vegetables are to its obesity epidemic: a near perfect answer, if only Americans could be persuaded to swallow them. But now Wal-Mart Stores, the giant discount retailer, is determined to push them into at least 100 million homes. …For all its power in retailing, though, Wal-Mart is meeting plenty of resistance -from light-bulb makers, competitors and consumers. …A compact fluorescent has clear advantages over the widely used incandescent light – it uses 75 percent less electricity, lasts 10 times longer, produces 450 pounds fewer greenhouse gases from power plants and saves consumers $30 over the life of each bulb. But it is eight times as expensive as a traditional bulb, gives off a harsher light and has a peculiar appearance. As a result, the bulbs have languished on store shelves for a quarter century; only 6 percent of households use the bulbs today. …selling 100 million compact fluorescent bulbs a year by 2008, … saving Americans $3 billion in electricity costs and avoiding the need to build additional power plants for the equivalent of 450,000 new homes. …During an extraordinary meeting in Las Vegas in early October, …Selling 100 million bulbs “is not a slam dunk by any stretch of the imagination,” Stephen Goldmacher, an executive at Royal Philips, the Dutch company that is one of the world’s largest light-bulb makers, told the group. …The attendees did not need to look far for evidence. Wal-Mart had asked the owners of the Mirage Hotel and Casino, where the conference was held, to commit to using the energy saving bulbs in its guest rooms in time for the meeting. The hotel politely declined. …In the past, Wal-Mart had sold them on the bottom shelf of the lighting aisle, so that shoppers had to bend down. In tests that started in February, it gave the lights prime real estate at eye level. Sales soared. …Wal-Mart will have to persuade its traditional consumers that it is worth paying a bit more at the checkout counter to save a significant amount money down the line, a seemingly simple task that few companies ever accomplish. …”It has taken the American public forever to grasp this,” said Charlie Jerabek, the chief executive of Sylvania….
May 2006. Try A Solar Water Heater. Andrew Korfhage. Coop America. With a solar water heater, you’ll get the hot water your household needs while saving money and energy and reducing your dependence on coal-fired power. After a year with their solar hot water heater, homeowners Bob Allen and Lyle Rudensey say they’ll never go back to relying on a conventional water heater. Even in gloomy, rainy Seattle, they are saving money and energy by heating all of their water with the power of the sun. “With a lack of leadership at the federal level, I feel it’s very important that we all do what we can to reduce our dependence on fossil fuels and reduce greenhouse gases,” says Lyle. “Solar hot water systems are a great place to start. They’re not as expensive as solar photovoltaics, and they’ll save you substantial amounts of energy and money.” …With all their savings combined, Lyle points out that his and Bob’s electric bills have dropped to a low of $5. “Plus, the water heater increased the value of the house,” Bob adds. “And it’s a hedge against future energy cost increases.” …”Some people might think that solar water heaters aren’t worth installing in a climate like the Pacific Northwest, but that’s not true,” says Lyle. “Germany gets about 70 percent as much sunlight as Seattle does, and they are the biggest users of solar power in the world. This is something everyone can do that really makes a huge difference.”
2006 Spring. California Illuminates the World. By Craig Canine, OnEarth Magazine. Excerpt: …Leading-edge policies and technologies that encourage efficiency have long been a California export…. Energy policy makers in other states as well as in the federal government look to California’s energy-conservation measures the same way political analysts view the New Hampshire presidential primary — as a bellwether for the nation. California was, for example, the first state to adopt efficiency standards for appliances. These went into effect in 1977 and were upgraded throughout the 1980s. Florida, Massachusetts, Connecticut, New York, and other states followed California’s lead, sometimes copying the California code verbatim. This shift at the state level convinced appliance manufacturers to join with efficiency advocates in lobbying for a uniform national standard, which Ronald Reagan signed into law in 1987. Thus began a process that continues to repeat itself. Since 2004 several other states have adopted at least some of California’s latest standards, many of which also wound up in last year’s federal energy bill. “The general pattern,” says Devra Wang, a staff scientist at the Natural Resources Defense Council, “is that California adopts new standards, other states follow, and then they’re adopted at the federal level.”
California’s efficiency standards for new buildings, introduced in 1978 and known as Title 24, have been replicated all over the world. The code governing new construction in Russia, for example, is cutting energy use by more than 40 percent, thanks to California. A similar effort now under way in China could wind up as California’s most enduring global legacy…. If the planet is to tackle the twin challenges of finding adequate energy resources to drive hungry economies while averting the worst consequences of climate change from burning fossil fuels, the West Coast is the place to look for leadership….
15 February 2005. Turning On the Lights Where Electricity Is Rare By ANDREW C. REVKIN. NY Times. It will be years before many of the 1.6 billion people still cooking, studying and working by the flickering light of kerosene lamps get on the grid, so engineers are trying in the meantime to improve on an existing improvised transmission system for electricity in poor rural areas – battery brigades. In many parts of Africa, for example, the first source of electricity has been car batteries, which are lugged every few days to towns to be recharged from diesel generators in ways that often shorten battery life and at rates that are 20 to 30 times as high as those paid by Americans…. A team led by Dr. Vijay Modi, the chairman of Columbia’s mechanical engineering department, has built a lunchbox-size battery pack and plug-in fluorescent fixture that can supply four hours of light to a household each night while consuming just one kilowatt-hour per month. “In the U.S., an average home consumes this much electricity in a little less than one hour,” Dr. Modi said.
February 2005 Saving Energy in the Kitchen. Greentips – Union of Concerned Scientists
October 2004. A good lab activity on inverse square/light intensity called “Shedding Light on the Inverse Square Law”, pages 44-48, Science Teacher Magazine, NSTA, October 2004, Vol 71, #8 [suggested by Eloise Farmer]
January 8, 2004. Let There Be L.E.D.’s. By IAN AUSTEN. NY Times. IT started innocently enough. Marcel Jean Vos, an interior and commercial designer in London, bought some light-emitting diodes to create a small lighting system in the kitchen of his apartment. Now, four years later, Mr. Vos has transformed a neighboring one-bedroom apartment into a space lighted entirely with L.E.D.’s, the solid-state technology more commonly associated with the tiny lights on electronic gadgets.
1996. Hybrid Lighting: Illuminating Our Future. By Michael R. Cates. Oakridge National Lab Review, Vol 29 No 3. http://www.ornl.gov/info/ornlreview/rev29_3/text/hybrid.htm