Renewable energy and water

The connections between climate, energy and water have become so profound, important and expensive that we cannot avoid recognizing their impacts all around us. There are many links between energy and water, but one of the most important - albeit ‘hidden’ - is the thirst thermoelectric power plants have for water. Currently, this need accounts for about 15 per cent of global water withdrawals (IEA 2012), and half of domestic water withdrawals in the United States. Most of these power plants rely on fossil fuels and contribute heavily to climate change. In turn, the spread of hydrologic variability has already become so wide that hydrologists have declared that “Stationarity is dead” in the water management sector (Milly 2008). This means we can no longer rely on the data of the past to predict the abundance or scarcity of water in the future. This has important implications for thermal power plants, as public and private attention is directed towards the greater development of low-water-use and low-carbon alternatives. Both low-water-use and low-carbon sources of energy are bountiful in the United States. As a bonus, they also emit no noxious gases nor produce a waste stream in any measure comparable to fossil fuels and nuclear power. All this, then, begs the question: How can renewable energy improve the reliability of our electricity system while not burdening our water resources? One example of the value of renewable technologies during times of drought can be found in the state of Texas, which experienced a major drought in 2011 that heavily strained the region's energy and water resources (Hoerling et al. 2012). The impacts of the drought on conventional electricity generation have been discussed previously in this volume (see Carter, Chapter 4), but we would like to note the robustness of renewable energy generation under condition of heavy drought.