Green Tags

On a grassy sandhill in eastern Colorado, Wray School District Superintendent Ron Howard parks his truck and points to the spot where his district’s new wind turbine will stand.“Right there, top of the hill,” he says.“The wind comes from the north, funnels through the canyon, then shoots up over this rise.”We get out and take the air.“Feel it?” he says. A persistent breeze combs over the hill, strong enough to make a street sign tremble.

Howard rattles off the specs. “It’ll be 335 feet high to the top of the propeller. Put out 900 kilowatts, enough to power the school district and most of the town, too,” he says, pointing behind him to the farm town of Wray, population 2,100, about 16 kilometers from the Colorado-Nebraska border. “You come back this time next year, it’ll be here turning.”

The Wray turbine will be turning thanks in part to renewable energy certificates—also known as RECs or green tags— which helped finance the project. When a renewable power source like a wind turbine generates a megawatthour (MWh) of electricity, it also produces a 1-MWh REC,which is an electronic financial instrument representing the green attributes of renewable energy (mainly, the fact that little or no carbon dioxide or other pollutants were released during its generation). Customers buy the electricity, of course, because it’s the most flexible and useful form of energy ever harnessed and can do myriad jobs that once required muscle power. But the RECs are worth something too—anywhere from US$1.50 to $20 per MWh on the retail market. Sold separately, they offer a way for individuals or companies to support renewable energy even if they cannot buy it directly from their local electric utility—plus they create a separate income stream for the power generators producing the renewable energy...