Hide your light in a bushel
Now I know we’re are all scared of the dark these days, but the best way to cut the energy used in lighting is to have none of it — or very little. Motion sensors can be a good way to keep lights turned off when they’re not needed. Dimmers can give you just the right amount, and timers can turn lights on and off when needed.
For the light you do need, changing the bulbs and fixtures can go a long way to saving money and greening your home. In future – think CFL and LED – a conventional incandescent bulb turns only around five to ten percent of its consumed energy into light, the rest goes out as heat.
Compact florescent bulbs (CFLs) come in different shapes, sizes, and colors. They cost more than an incandescent, but use about a quarter as much energy and last many times longer (usually around 10,000 hours). A CFL pays for its higher price after about 500 hours of use. Also, because CFLs release less heat, not only are they safer, but your cooling load is less in the summer. CFLs aren’t hard to find anymore, and many cities give them away for free. Wal-Mart has plans to sell 100 million of them.
LEDs, or light emitting diodes, are extremely energy efficient and long-lasting. They still cost more than CFLs, but use even less energy and last even longer. An LED light bulb can reduce energy consumption by 80-90% and last around 100,000 hours. One of the best UK sources is at https://www.yourwelcome.co.uk.
Most LED lamps on the market have the bulbs built into them, so you buy the whole unit. For screw-in bulbs, check out Ledtronics, Mule, and Enlux. For desk lamps, try Sylvania and Koncept. For more designer models, look at LEDs from Herman Miller and Knoll or the general category of Vessel rechargeable accent lamps
By far, the best source of light we know is yes, the sun, which gives off free, full-spectrum light all day. Keep your blinds open, put in some skylights, or, of you are designing a home or doing a renovation, put as many windows on the south-facing side of the house as possible. To take it even further, sunlight can be piped inside via fiber optics and other light channeling technologies. Try the Sunpipe, the work of the Oak Ridge National Laboratory, developments coming out of Queensland University of Technology, FluoroSolar, and the Suntracker. The University of Nottingham has also integrated daylight into its new Creative Energy Homes.
A heliodon is a device that allows architects, builders, and engineers to simulate the effects of sunlight on the lighting needs of building designs.
According to a report published by the International Energy Agency (IEA), a global switch to efficient lighting systems would trim the world’s electricity bill by nearly one-tenth. The carbon dioxide emissions saved by such a switch would, it concludes, dwarf cuts so far achieved by adopting wind and solar power. According to Paul Waide, a senior policy analyst with the IEA and one of the report’s authors, “19% of global electricity generation is taken for lighting that’s more than is produced by hydro or nuclear stations, and about the same that’s produced from natural gas.”
According to the federal Energy Star program: If every American home replaced just one light bulb with an ENERGY STAR, we would save enough energy to light more than 2.5 million homes for a year and prevent greenhouse gases equivalent to the emissions of nearly 800,000 cars.