Water is the source of all life (and energy)
Posted May 19, 2010 at 7:54 am 
Filed in: Energy and water are inextricably linked. This relationship is already under considerable strain and will be exacerbated by population and economic growth, and global climate change. More water-intensive energy development processes (oil sands and hydraulic fracturing for example) will exacerbate this strain even further. Downstream, electricity generation using nuclear power and concentrating solar power is also highly water-intensive (wind, natural gas etc. are much less so however). Biofuels potentially require more water than them all.
Erica Gies, writing in the New York Times, explained this week that solar developers in California have begun finding that water availability is a significant constraint. Ms. Gies notes that droughts have caused temporary nuclear power plant closures in Australia, France, Germany, Romania and Spain in the past decade. She also references the interesting technological changes in water use by thermoelectric power plants. First, came the ‘once-through’ system, which was cheap and efficient. Today, ‘wet cooling,’ which uses the cooling effect of evaporation, is also widely used. This process uses about 3 percent of the water that a ‘once-through’ system does, but loses 90 percent of it to vapor. It is however, more expensive. A newer, even more expensive and less efficient process, ‘dry cooling’ uses fans to push waste heat into the atmosphere instead of into water.
In the case of California, discouraging the use of freshwater for cooling affects the development of new power generation. Ms. Gies interviews Terry O’Brien, Deputy Director for Power Plant Licensing at the California Energy Commission. He notes that they have “three applications in-house for a solar-trough technology from Solar Millennium, and they made the decision to go to dry cooling before they filed.”
Going forward, and from a national perspective, this is a critical issue. How are we going to address it? We can start by investing in research, gathering better data, promoting less water-intensive electricity generating methods, and continuing the development of important processes like ‘dry cooling,’ explained above, that can be implemented sector wide (my list is definitely non-exhaustive). We also need to bring energy and water policymaking together. Some progress is being made in this area (e.g. H.R. 3598: Energy and Water Resources Integration Act, which passed the House in December 2009 and was referred to the Senate Committee on Energy and Natural Resources), but more is certainly needed.
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