Q: My power company, Georgia Power, offers an option to purchase solar renewable energy certificates (SRECs). Where does my money actually go?

—Brian in Atlanta, Georgia 

A: The Solar Energy Industries Association, which represents 1,000 solar businesses, says SRECs are “an attractive option, especially when determining how much incentive is necessary to get the market going.” Still, your skepticism is warranted. 

When you buy SRECs, organizations like Green-e certify that a company acquires a given amount of “renewable” electricity. Those pristine electrons don't zip straight to your TV; they go to the power grid as a whole. 

Fine. But definitions of “clean power” vary among states where SRECs are offered. Some include natural gas or nuclear! Your SRECs look legit, though some of Georgia Power's virtuous electricity is derived from biomass, which could mean wood from Georgia forests. SREC power is available for a penny more per kilowatt-hour than dirty power—which would hike bills only $12 a month for the average Georgia household. To see if SREC power is truly clean in your area, inquire with your utility or the state utilities commission.