Warming climate likely to have ‘minor’ impact on power plant output

From Duke University:

DURHAM, N.C. — Future climate warming will likely cause only minor cuts in energy output at most U.S. coal- or gas-fired power plants, a new Duke University study finds.

The study — the first of its kind based on real-world data — rebuts recent modeling-based studies that warn rising temperatures will significantly lower the efficiency of power plants’ cooling systems, thereby reducing plants’ energy output. Those studies estimated that plant efficiencies could drop by as much as 1.3 percent for each 1 degree Celsius of climate warming.

“Our data suggest that drops in efficiency at plants with open-loop, or once-through, cooling systems will be a full order of magnitude smaller than this,” said Candise L. Henry, a doctoral student at Duke’s Nicholas School of the Environment. “Reductions at plants with wet-circulation, or closed-loop, systems — which can be identified by their cooling towers — may be even smaller.”

“In large part, this is because plant operators are already constantly adjusting operations to optimize plant performance under changing environmental conditions,” she said. “That’s a key consideration the past studies overlooked.”

The new findings do not, however, signal an all’s clear for the power industry, the Duke researchers cautioned.

“The impact of future droughts associated with global warming could still significantly affect plant operations and output by reducing the availability of water for cooling,” said Lincoln F. Pratson, Semans-Brown Professor of Earth and Ocean Sciences at Duke.

Henry and Pratson published their findings this month in the peer-reviewed journal Environmental Science & Technology.

To conduct their study, they analyzed hourly temperature and humidity data recorded at National Climatic Data Center (NCDC) stations and U.S. Geological Survey river gauges near 39 U.S. coal- or natural-gas-fired power plants over a seven- to 14-year period. By correlating this data with the plants’ hourly heat input and energy output records, obtained through …

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