Lighting accounts for about 40 percent of electricity used in commercial buildings; another 10 percent of electricity in most buildings goes to cool the heat generated from lighting. That means Cool Lighting is typically the fastest way to save energy and reduce costs - sometimes by up to 90 percent, often with a 30 to 60 percent rate of return. When companies improve lighting, they often boost productivity. 

The problem is that most lighting systems were designed according to outdated building codes intended for people writing on horizontal surfaces or using typewriters, as opposed to today's vertical, back-lit computer screens. As a result, most buildings are overlit, mislit, or both. 

Lighting upgrades that improve quality while reducing demand by 50 to 70 percent are routine. In particular, daylight, which creates no pollution, is the most natural and the most associated with performance gains. 

• Boeing Aircraft Company cut lighting electricity use by as much as to 90 percent in several million square feet of its facilities. The investment yielded a 50 percent financial return. More importantly, the company realized major, measurable productivity gains from the improved lighting in their plants. The upgrades save 270 million kilowatt-hours of electricity annually, displacing 100,000 tons of carbon dioxide emissions, 8,000 tons of sulfur dioxide, and 4,000 tons of nitrogen oxides. Boeing estimates that if every company adopted the lighting they installed "it would reduce air pollution as much as if one-third of the cars on the road today never left the garage." 

• Ortho-McNeil Pharmaceuticals reduced lighting energy by 63 percent at their million-square foot-facility in Raritan, New Jersey using the “Green Lights” method developed by the Environmental Protection Agency. They saved almost four million kilowatt-hours worth $320,000 annually, with an investment that paid for itself in just two and a half years. 

• Elkhart General Hospital in Indiana reduced lighting electricity by more than 70 percent over 430,000 square feet of space, for a total annual savings of $102,000. The upgrade cost $85,000 and prevented emissions of 1,500 tons of carbon dioxide, 13 tons of sulfur dioxide, and 6 tons of nitrogen oxides. 

• The million-square-foot St. Francis Hotel in San Francisco reduced lighting electricity 82 percent. The investment of $76,000 produced annual savings of $85,000.