How to choose clean-energy sites

Deciding where to install wind turbines and solar panels seems straightforward: Pick gusty and sunny spots. But researchers say the problem is a bit more complicated. To get the most emissions reductions and health benefits, the United States may need to focus its clean energy efforts on some unlikely regions.

Switching to wind and solar energy can cut carbon dioxide emissions and levels of pollutants that weaken people’s health. “It is natural to think that the windiest or sunniest sites will yield the best performance,” the study authors write in Proceedings of the National Academy of Sciences. But if a region already uses energy sources with relatively low CO2 emissions, such as gas-fired plants, residents may not see a dramatic improvement.

The researchers predicted the effects of installing wind turbines at more than 33,000 sites in the United States. CO2 emissions fell the most in the Midwest, which currently relies heavily on coal-fired generators. In contrast, California saw a relatively small drop in emissions, partly because the state already uses gas-fired plants. Annual health and environment-related cost savings per kilowatt were much higher in Indiana and West Virginia than in California.

The team performed a similar analysis for solar panel installation at more than 900 U.S. sites. Solar panels in the Southwest will generate the most energy, the researchers predict, but Midwest and Eastern states will enjoy the steepest reductions in emissions of CO2 and other pollutants. “Remarkably, if the goal is to improve air quality and human health, Arizona and New Mexico are among the worst locations for solar,” the authors write. — Roberta Kwok | 24 June 2013

Source: Siler-Evans, K. et al. 2013. Regional variations in the health, environmental, and climate benefits of wind and solar generation. Proceedings of the National Academy of Sciences doi: 10.1073/pnas.1221978110.

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