An LED bulb already far outlasts a standard bulb -- LEDs run for approximately 100,000 hours -- but cost around $60 dollars a bulb. Steven DenBaars, a UC professor of material science, points out that the prices have been declining by about 50 percent a year, and should drop to about $20 a bulb in two years. The bulbs would then pay for themselves in terms of energy savings in about a year, especially in large stores and warehouses where lights are on almost all day, he said.
Another disadvantage of traditional bulbs is they only convert about 5 percent of the energy they use into light, and the rest is dissipated as heat. Since U.S. Department of Energy figures reveal that about 22 percent of electricity used in the United States goes toward lighting, converting to LED bulbs would have a profound economic and environmental impact.
DenBaars said that if 25 percent of U.S. light bulbs were converted to 150-lumens-per-watt LEDs, the nation would eliminate the need to build 133 coal-burning power stations and reduce carbon emissions in the atmosphere by 284 million tons.
However, the LEDs that are currently available fall way short of 150-lumens per watt. Such technology may be on the horizon as a couple of companies have developed experimental LEDs that can put out around 130 lumens per watt.
In DenBaars' 150-lumens-per-watt example, the United States would save about $115 billion by 2025 in utility costs.
"Multiply that by three and you get the worldwide savings," he said.