Generating electricity using wind, solar and geothermal technologies produces none of the greenhouse gases fossil fuel-based plants create and could help reduce our dependence on foreign oil and gas. But even clean electricity requires transmission lines, and the remote locations of many renewable resources is forcing some tough conversations regarding potential tradeoffs involved in bringing renewable energy to the market.

Wind energy is proving to be one of the winners in the push toward cleaner electricity production. Wind technology is second only to hydropower as a renewable electricity producer, and its generation capacity is expected to grow by 3,000 megawatts (MW) in 2007, topping last year’s record of more than 2,400 MW. In the short term, the industry is even becoming a victim of its own success, as the demand for new towers and turbines is outpacing manufacturers’ production capabilities.

Parts shortages are expected to be temporary, as new turbine-, tower- and blade-manufacturing plants are under construction. However, wind and other renewable efforts face a longer term hurdle: the need for new transmission lines to connect these remotely located resources to the larger electrical grid. Strained transmission capacity already is recognized as a hazard in many densely populated regions, but many areas with the highest capacity for potential renewable development lack any capacity at all.

“The infrastructure need is very high,” said Dave Dworzak, director of reliability for Washington, D.C.-based Edison Electric Institute, the association for investor-owned electric utilities.

This infrastructure need is underscored by a battle now underway in Southern California. San Diego Gas & Electric (SDGE) has proposed a 150-mile line called the Sunrise Powerlink to connect San Diego to geothermal and proposed solar-collector plants in the state’s Imperial Valley. The line would cross through the Anza Borrego Desert State Park, along with other undeveloped, rural areas. Many environmentalists oppose it.

SDGE says the line is critical to the utility’s efforts to comply with California’s mandate that at least 20 percent of electricity utilities sell in the state come from renewable sources by 2010. Such targets, called renewable portfolio standards (RPSs), now exist in 22 states, but California’s is considered the strictest because of its near-term deadline.

The Sunrise Powerlink is the most prominent current battle in the effort to add renewable-energy-related transmission capacity, but the political issues surrounding new transmission-line construction could stop many projects before they even get to the public hearing stage. The financial structure supporting renewable-energy development and its related transmission capacity poses additional challenges for developers of these projects.

Wind farms and other renewable facilities are built and owned by independent power producers (IPPs). To receive financing for these facilities, IPPs must show potential lenders long-term contracts signed by power purchasers to prove financial viability. However, many utilities won’t sign unless the IPP agrees to underwrite transmission construction costs, and it is impossible for the IPP to do without the financing in place.

“It’s a very circular process,” said Shalini Vajhalla, a fellow at Washington, D.C.-based Resources for the Future (RFF), an independent institute dedicated exclusively to analyzing environmental, energy and natural resource topics.

Vajhalla is one of a team of researchers gathering information necessary for developing more coordinated regional approaches to transmission shortfalls. RFF’s effort involves mapping proposed and potential renewable projects and evaluating transmission access to those resources. RFF is developing metrics for comparing the difficulty of siting transmission lines across state regulatory jurisdictions, which is important in states where RPS regulations are in effect.

“All of these efforts consider renewables,” Vajhalla said of state-level legislation geared to greenhouse-gas reductions, and Vajhalla noted the futility of such moves if transmission difficulties aren’t also addressed.

Sen. Jeff Bingaman, D-N.M., introduced a national bill on RPS targets this spring. Although national standards could be unwieldy, some see regionally coordinated transmission plans as key to developing solutions that enable resource access without damaging the environment.

“If you just plan one line at a time, you might have problems finding alternatives,” said Sheryl Carter, director of western energy programs for the Natural Resources Defense Council, noting that a bigger picture approach provides greater opportunity for meeting environmental and electricity-demand goals. She added that addressing transmission needs is crucial to the success of any renewable-development effort.

“Renewables, in particular, tend to be much farther away from the load,” Carter said. “If we’re going to really aggressively develop renewables, we’re going to have to be able to access them.” EC

ROSS is a freelance writer located in Brewster, Mass. He can be reached at chuck@chuck-ross.com.