Solar energy systems are getting a boost from a long-used energy industry tool, called power purchase agreements, that help finance installation of the clean energy source by selling several years' worth of electricity under a single contract.

Companies such as Microsoft Corp, Macy's Inc , Target Corp and Whole Foods Market Inc have signed such agreements with solar developers to set 15- to 20-year fixed costs for their electricity, reducing their reliance on utility-supplied power and trimming their carbon output while getting predictable power bills -- often below the typical retail price level.

While those contracts have so far relied on subsidies or tax credits from states to make them attractive, other strategies, from waste reduction to design efficiencies, are becoming more commonplace.

Nike's newly released Air Jordan XX3 sneaker was designed to be assembled like a jigsaw puzzle, reducing the need for toxic adhesives, and uses recycled polyester from bottles and scrap material from the factory floor.

Consumer products maker Johnson & Johnson focused on implementing energy efficiencies in its facilities and created an "enhanced best practices" checklist that seeks innovations that provide a return on investment within five years.

The move has paid off, the company said in the report, by reducing its greenhouse gas emissions by 34,500 metric tons in 2006 -- and creating an annualised cost savings of $30 million.