In many ways, the definition of green power - like art - remains in the eye of the beholder. Most experts agree that power from wind, solar, geothermal, and biomass sources qualify. A new technology, fuel cells, will likely earn the "green power" moniker, too, if researchers can make them a feasible energy alternative.
But after that, things get dicey.
For example, biomass (the burning of waste from sawmills and farms to create electricity) causes more pollution than hydroelectricity. But many environmentalists don't like hydro-power dams because they block fish runs and change river flows. Some advocates draw a distinction between big or "high-impact" dams and "low-impact" hydro facilities. The latter qualify as green power, they say.
What about natural gas? A new generation of combined-cycle combustion turbines produce energy far more efficiently and cleanly than other fossil-fuel energy plants. But many green-power advocates reject the technology because it's not renewable, and gas-drilling can damage the environment.
So how's a consumer to tell "green" from "near-green"? If you're located in a state that has deregulated its energy and are considering participating in a utility's green-power program, find out what fuel sources the utility calls green. For more information on green power, contact the Renewable Energy Policy Project (www.repp.org) or the Green-e Renewable Electricity Certification Program (www.green-e.org). The Green-e program actually certifies utilities' programs that meet its standards.
(c) Copyright 2001. The Christian Science Publishing Society