ENERGY EFFICIENCY Improved technologies can reduce our use of energy and other resources by wasting less. For example, we generally use light bulbs because we want light. But about 95% of the electricity that powers an incandescent bulb produces heat – only 5% goes to light. CFL and LED lights produce much more light than heat and thus need less electricity to produce the same amount of light. Products that bear the Energy Star^® label are independently certified to meet or exceed high energy efficiency standards.