Congress should consider setting a price on pollution to encourage use and development of clean energy sources, recommends a National Academies report. Governments should also better support clean energy technologies, the report says. These recommendations are the top two among several steps identified by the report’s panel to improve the performance and cost-competitiveness of clean electricity generation and grid technologies. Carbon-dioxide-free, nonpolluting electricity generation is among the U.S.’s “greatest challenges” and “greatest opportunities,” notes Charles O. Holliday Jr., chairman of the report’s panel and of Royal Dutch Shell. The report acknowledges recent market expansion and price declines for some clean electricity technologies but warns that much greater market penetration of these technologies is needed to address the impacts of climate change and harms to human health caused by pollution. The report provides an overview of clean energy development needs, but many of its recommendations have been voiced in earlier reports and have proven politically difficult to implement.