Over the past 24 years, the National Renewable Energy Lab (NREL) has helped to bring a variety of green energy technologies to marketSOLAR

Photovoltaic modules have tumbled to $3 per watt of generating capacity from $20, while the modules have more than doubled in efficiencyWIND

Generation costs have fallen 90%, to 4 cents per kilowatt hour from 40 cents, in large part due to research at the largest turbine testing facility in the U.S.BUILDING EFFICIENCY

Advances in building design, heating and air-conditioning systems, lighting, and insulation can slash energy usage by 40% to 80%