This report examines the potential impact of low carbon electricity generation technologies on water resources and how these water considerations might shape renewable generation choices. The report argues that water requirements for power generation depend on generation technology, type of cooling technology used in thermoelectric power generation and electricity demand itself. It highlights that climate-related water constraints are already affecting electricity generation in many places. Acute water-energy conflicts are arising during droughts and summers, when energy demand is high and water availability is low. Climate change may further exacerbate this problem and bring scarcity and drought risks to new areas, where stream flow regimes currently support hydropower and cooling water withdrawals.The paper uses California, United States, as a case study to evaluate the state's renewable energy development. The findings show that in 2009, approximately 20 per cent of all electricity generated within California came from renewable resources such as wind, solar, geothermal, biomass and hydroelectric facilities and this is expected to rise to 33 per cent by 2020 under the state’s Renewables Portfolio Standard (RPS), which was adopted in 2002 and enhanced in 2011. The paper notes that greenhouse gas emissions, water withdrawals and water consumption all increase as overall electricity demand increases. Under the RPS, emissions and water withdrawals drop, but water consumption increases. To conserve water, the report gives the following recommendations.

Reduce the overall demand for electricity, through efficiency improvements in electrical devices, electricity transmission and distribution systems and power plant operations.
Decrease the need for water withdrawals through water recycling and reuse.
Use energy storage technologies to help reduce stress on water resources.