Lots of sun, no water

Nevada has been called the Saudi Arabia of solar energy, but unfortunately most solar thermal generating schemes require water (more advanced systems use metals like sodium, and photovoltaic panels don't require water but are far less efficient).

Similarly, geothermal and biofuel plants need a lot of water as well.

From the New York Times:

Here is an inconvenient truth about renewable energy: It can sometimes demand a huge amount of water. Many of the proposed solutions to the nation’s energy problems, from certain types of solar farms to biofuel refineries to cleaner coal plants, could consume billions of gallons of water every year.

“When push comes to shove, water could become the real throttle on renewable energy,” said Michael E. Webber, an assistant professor at the University of Texas in Austin who studies the relationship between energy and water.

Conflicts over water could shape the future of many energy technologies. The most water-efficient renewable technologies are not necessarily the most economical, but water shortages could give them a competitive edge.