Light SwitchBy using the best technologies, 70-90 percent of the energy used for lighting can be saved without any loss of function. Improving lighting design can also lower maintenance costs and increase worker productivity. In fact, quality lighting has been shown to increase sales, improve student grades, and raise worker productivity.

Lighting directly consumes 20 percent of electricity in the United States. According to the Rocky Mountain Institute, if advanced lighting technologies were fully applied in the United States, the resulting electricity savings would eliminate the need for 120 1,000-megawatt power plants. Taking this action would save ratepayers $30 billion a year just on the cost of operating those plants.


Technology iconWhen comparing energy-saving lighting with standard lighting, it is important to consider the light output, or lumens. With ENERGY STAR qualified light bulbs or fixtures, you get the same amount of light for less electricity. For example, a 20-Watt energy-saving bulb will provide the same amount of light/lumens (or more) as a 60W incandescent one. A common misconception is that a bulb's wattage describes the amount of light it gives off - this is not fully accurate.

  • Watts: are the measurement of the electrical power. In lighting, watts measure the amount of power needed to make a bulb operate.
  • Lumens: are the standard measurement of light output.

The ratio of light output to power input is known as efficacy and is measured in lumens per watt. Efficacy can be thought of in similar terms to the "miles per gallon" rating we use to determine gas mileage in vehicles. The more lumens per watt, the better value for your energy dollar.

  • Miles = Lumens. What we want to get
  • Gallons = Watts. What we have to put in

Quick Web Links
Energy Star's Product Provider Directory

Economic Savings

Economic Savings iconThe prices of energy-saving compact fluorescent lamps (CFLs) range from $4 to $15 depending on the type of bulb. However, rebate programs are becoming more and more common. Check with your local utility company to see if there are any available rebate programs in your area. While CFLs are more expensive to purchase than conventional incandescent bulbs you save on average $25-30 per bulb in energy costs over their lifetime. CFLs last much longer (typically 10 times longer) than incandescent bulbs as well. Additionally, most CFL manufacturers offer a warranty that covers the lifetime of the product. Despite the higher initial investment, energy-efficient lighting offers a significant return on investment. Consider the following cost-effectiveness example:

Cost-Effectiveness Example
Performance Standard Life CFL
(moderate use)
Extended Life CFL
(high use)
Incandescent Bulb Replaced Recommended CFL (6,000 hour life) Incandescent Bulb Replaced Recommended CFL (10,000 hour life)
Input watts
(lumens per watt)
60W (15 lpw) 17W (60 lpw) 60W (15 lpw) 17W (60 lpw)
Annual Energy Use 72 kWh 20 kWh 120 kWh 34 kWh
Annual Energy Cost $4.30 $1.20 $7.20 $2.04
Lifetime Energy Cost $18 $5 $30 $9
Lifetime Energy Cost Savings $13 $22

Quick Web Links
Energy Star Lighting Calculator
Federal Energy Management Program Calculator

Environmental Benefits

Environmental Benefits iconAccording to the EPA, replacing one incandescent bulb with an ENERGY STAR qualified CFL will prevent more than 1,300 pounds of carbon dioxide and 20 pounds of sulfur dioxide from being released into the air. If every US household made just one such switch, annual pollution savings would be equivalent to removing more than 800,000 cars from the road.

While CFL bulbs present many environmental benefits that contain a trace amount of mercury and should be disposed of properly.


Links iconThe Department of the Interiors Energy Efficiency and Renewable Energy Page provides a wide range of resources to help green facilities

ENERGY STAR is a government-industry partnership program helping businesses and individuals protect the environment through superior energy efficiency. The ENERGY STAR Lighting site provides good information on energy efficient lighting products and national rebate programs.

The Illuminating Engineering Society of North America (IESNA) is the recognized technical authority on illumination. The IESNA site provides information on all aspects of good lighting practice, programs, publications, and services.

The Lighting Research Center is part of the School of Architecture at Rensselaer Polytechnic Institute. The leading university-based lighting research center, the LRC has an international reputation as an objective source. At this site, you'll find information about lighting technologies, applications, and products.

The Efficient Lighting Initiative is an international program for certifying the quality and efficiency of lighting products. It is operated by a non-profit organization, the ELI Quality Certification Institute, for the benefit of end users, policymakers, and lighting suppliers worldwide.