What it means. A major roadblock to wider residential use of renewable and alternative energy—whether wind, solar, biomass, or geothermal—is often the sky-high cost to buy and install the systems. In our October 2009 story on solar water heaters and pellet stoves, for instance, we report that it could take 20 years to recoup the initial $4,000 to $8,000 investment of either system. Never mind the payback period on a whole-house solar or wind system, which can top $50,000.

With energy leasing, also called renewable-energy or green-energy leasing, rather than purchase a system, you lease it from a provider, just as you would a car, paying a fixed monthly fee that's less than what their electric bill would otherwise cost. A power-purchase agreement (PPA) is like leasing, except that you pay for the energy you use, not a flat fee. The leasing companies profit from the lease agreement and also reap any available tax credits and rebates, which you forfeit your claim to.

Why the buzz? Energy leasing and PPAs exist in some states, including California, Connecticut, and Massachusetts. Two bills before Congress (S. 1379 and H.R. 2336) hope to create a nationwide market by luring increased private capital. "I've introduced the [bill] to help save consumers money on their energy bills and jump-start the market for renewable energy in Rhode Island and throughout the country," said Sheldon Whitehouse, the Rhode Island Democrat whose Senate version of the bill is known as the Energy Efficiency in Housing Act of 2009.

Representative Ed Perlmutter sponsored the House counterpart, known as the Green Act of 2009. In an e-mail, the Colorado Democrat explained that "right now there is a patchwork of renewable energy and energy-efficiency regulations and incentives in the country" and that establishing federal standards will "end this confusing landscape while allowing states to continue to develop programs customized to their needs."

Both bills are currently in committee.—Daniel DiClerico | e-mail | Twitter | Forums | Facebook

Essential information: Find out how to slash your annual energy bill by up to $1,500 and visit our Energy Saving & Green Living guide for more information on boosting the efficiency of your home and saving money on heating and cooling your home.