US Renewable Energy Drive Will Aid Drought-Stricken South

Posted on 05. Jun, 2009 by Ross in Energy News, North America

Continual droughts across the southern states of the US will be lessened by the same projects which will secure America’s low-carbon future - wind and solar power stations.

Water supplies across much of the American south have been pushed to breaking point from a combination of inefficient usage, increased agricultural and industrial demand, and poor rainfall levels - this latter factor is only likely to become worse as climate change begins to affect global weather systems.

65% of fresh water withdrawn in the southeast US is by power stations, in contrast to just 13% by households 13% by irrigation and just 8% by industry. This places a massive burden on the water resources of drought-stricken states, as well as intrinsically binding the security of energy supplies and energy prices to the availability of water.

Conventional (thermoelectric) power stations all rely on vast quantities of water in order to produce electricity. Whether the power comes from coal, gas, oil or nuclear sources, the resultant heat generation by combustion or fission is used to heat water into steam. The steam then drives turbines which convert the kinetic energy into electrical energy. A lack of locally-available water can force power plants to close, as French power company EDF found in 2003 to the cost of €300 million: it needed to import vast quantities of energy after a quarter of its nuclear plants were forced to close due to drought.

Some renewable technologies are also susceptible to droughts though. Geothermal and solar-thermal power stations also generate energy by heating water, whilst hydroelectric installations have more obvious direct links. In the case of solar-thermal power stations, the irony of course is that they are most effective in geographical locations with low water reserves due to the intensity of solar energy which exists there, e.g. deserts.

Wind power and solar photovoltaics hold the promise to break the intrinsic inter-dependence of water and power generation. Both technologies convert environmental energy directly into electricity without the need for continuous supplies of water. Therefore as well as cutting carbon emissions, these technologies will also free up over-exploited water resources for other uses and decouple energy prices and shortages from drought.

Image by Jeremy Moran @ Flickr