WASHINGTON, D.C.” A growing portion of U.S. states’ electricity is being provided by renewable energy, according to a new report written by a University of Michigan professor.

States are using increasingly aggressive and ambitious Renewable Portfolio Standards (RPS) to spur economic development and to create a reliable and diversified supply of electricity, as well as to reduce greenhouse gas emissions and conventional pollutants, according to report released today by the Pew Center on Global Climate Change.

Twenty-two states and the District of Columbia have implemented an RPS.

“More than half of the American public now lives in a state in which an RPS is in operation,” said Barry Rabe, the report’s author. He is a U-M professor in the Gerald R. Ford School of Public Policy and the School of Natural Resources and Environment.

In the report,” Race to the Top: The Expanding Role of U.S. State Renewable Portfolio Standards,” Rabe builds on earlier Pew Center analyses of the state role in climate policy development. The proliferation of RPS plans at the state level provides real-world models of whether a federal RPS may be a feasible option to increase the nation’s use of renewable energy sources as part of a larger energy and climate change policy.

“If we are to successfully address climate change, we must increase our use of renewable energy,” said Pew Center President Eileen Claussen.” Engagement between states and federal policymakers on this issue has been surprisingly limited, and is long overdue. We need to begin thinking both about how the federal government can be most effective in this arena, and also how to enhance interstate collaboration.”

In addition to examining challenges and opportunities inherent in policy design and implementation, the report includes case studies of five states” Texas, Pennsylvania, Colorado, Massachusetts, and Nevada. Rabe explores the political and economic advantages and pitfalls in each state, and finds an unusually high degree of bipartisan support and rapid expansion of RPS programs at the state level. Economic development and job creation also emerge as drivers in virtually every state.

Despite the many advantages of state-level RPS policies, the report also finds that states face challenges. States increasingly are grappling with electricity transmission capacity constraints, differential treatment of various renewable sources as well as facility siting concerns.

“The biggest challenge in the future will likely revolve around the need for interstate collaboration and dialogue as the questions of cooperation across state boundaries arise,” Rabe noted.” Ultimately, federal and state regulators will need to work together in the event of adoption of a federal RPS.”

States are already cooperating regionally and that pattern is likely to continue, but there is much the federal government could do to enable a significant expansion of renewable energy, the report notes.

The Pew Center’s recent Agenda for Climate Action recommends that renewables should be a key element of a climate-friendly energy path for the United States. It describes the areas in which federal efforts are needed, including R&D funding and technology development. Federal support could involve incentives for uniform grid interconnection standards at the state level, or the creation of a uniform system for tracking renewable energy credits across the country. In designing federal policies, Congress should recognize the regional differences in renewable resources and existing state-level policy actions, the report says.

Pew Center’s web siteBarry Rabe