Water cooling leading to increased water temperature and loss of water as fog
“There are cost effective things that the power sector can do that would conserve water that will also reduce the amount of greenhouse gas emissions,” said Paul Faeth, director of energy, water and climate at the CNA think tank’s Institute for Public Research.
CNA Corporation in its July 2014 report, “A Clash of Competing Necessities” documents the use of water for generating electric power as follows: an estimated 40% of all freshwater withdrawal in the US is used for thermal cooling. Coal with carbon capture and storage (CSS) came out top, using 4.3 cubic metres of water for every MWh.
Nuclear is a close second using 4.2, coal alone uses 2.3, natural gas 1, wind uses zero, and PV uses 0.1 cubic metres per MWh.
For ‘consumption’ of water, whereby water is completely removed from the local environment, CCS uses 3.2 cubic metres per MWh, nuclear 2.5, coal 1.9, natural gas 0.7 – and again wind uses zero and PV uses 0.1.
Water concerns “for policy makers and for many people are also a higher priority than climate change,” he said, adding that in drought it “doesn’t matter what the cause of drought is you still have to respond, and if you can respond in a way that is cost effective and mitigates emissions, such as using wind and PV, then that is a real plus.”