the seventh. SustainLane credits that success to the state's ambitious renewable portfolio standards.

The UCS expects renewable energy initiatives to produce a significant environmental impact. The group projects that 21 states and the District of Columbia will collectively reduce their greenhouse gas emissions by 108 million metric tons of carbon dioxide by 2020, due to renewable energy requirements. That amount is equivalent to taking 17.7 million cars off the road, according to the UCS.

But while the leading states are making progress, the nation as a whole has plenty of work to do. Excluding hydroelectric power, just 2.5 percent of electric power generated in the United States currently comes from renewable sources, Deyette said. At the current growth rate, that number would reach 6.3 percent by 2020.

That portion could expand if efforts to establish a federal standard of 20 percent succeed.

"I don't think 20 percent is a stretch, but it's aggressive," Deyette said, "particularly for a state that's currently at 2 percent."

He said the U.S. Senate passed three 10 percent requirements that ultimately failed during the past several years, but thanks to the 2006 Democratic congressional takeover, several 20 percent requirement proposals now brew in Congress.

A New Energy Landscape
Rising electricity consumption and mounting pressure to develop renewable energy sources put public utilities in a bind because most new energy technologies remain immature and relatively expensive.

Wind, a seemingly ideal source of renewable energy, is among the fastest growing alternative power sources. But not all areas of the country have access to the reliable air currents needed for that type of power generation. Furthermore, wind farms aren't that easy to set up.

"It's not just a matter of siting a wind turbine or establishing a wind farm," Riedinger said. "Typically where there is wind -- and somewhat steady wind so you can get the most out of each turbine -- you're nowhere near the electric grid. You also have to establish the transmission lines to carry the electrons from the turbine to where they can be used.

"Siting those lines is often more difficult than siting a wind farm," he continued, "whether it's off the shore of Cape Cod or on mountain peaks in Vermont."

Local resistance often stalls a utility's ability to establish wind power transmission lines. "Siting one line can take more than a decade," he explained. "Everybody wants the electricity, but no one wants the lines running near their homes or where they can see them, which is understandable."

Utilities also actively pursue solar power. San Francisco voters passed a $100 million bond for solar research in 2001. The measure succeeded in response to government findings that Enron and other electricity traders suppressed power plant operations in California, causing rolling blackouts and price hikes.

But solar energy remains too expensive to commercially compete with other sources, and government efforts to promote solar technology may be having a mixed impact, according to Lori Bird, senior energy analyst at the National Renewable Energy Laboratory.

"Some state policies say a certain fraction of renewable energy has to come from solar," she said. Those policies spurred solar energy development, but they also increased competition for critical materials.

"There's been so much growth in the industry during the last couple of years that there's a shortage of silicon," Bird said. "The industry has been somewhat constrained by that. The global demand for solar is very strong, and the U.S. has to compete with Germany and Japan and so forth in trying to get solar panels."

Jerry Taylor, senior fellow at the Cato Institute, said high costs will prevent solar energy from playing a significant role in near-term renewable energy conversions.

"It's going to be nowhere on the radar screen unless the government just mandates that

Andy Opsahl  | 

Andy Opsahl is a former staff writer and features editor for Government Technology magazine.