Most of the electricity generated around the world is produced using water intensive processes. Thermoelectric power plants use fossil and nuclear fuels to heat water in large boilers where steam is created to drive large turbine generators. Water is circulated throughout the power plants in huge quantities to cool the turbines, clean scrubbers and boilers, and perform a number of other tasks. Chemicals are often added to the water to extend the life of the machinery and prevent biological growth in the cooling towers. And many power plants return no water to the source - it is all lost to evaporation. Other power plants return water to the source at greatly elevated temperatures, destroying or radically altering the local ecosystems.

These thermoelectric power plants are responsible for creating enormous levels of stress on local, regional and national water supplies in the U.S. and around the world. Besides some water used in module or turbine manufacturing processes and a negligible amount needed to occasionally clean them, solar and wind energy systems require no water to keep them operating. Furthermore, the substitution of on-site solar thermal hot water systems in place of electric water heaters also saves considerable quantities of water.

Billions of gallons of water can be saved every day through the use of solar, wind and other renewable energy systems. According to a United States Geological Survey report published in 2000, 195 billion gallons of water are withdrawn every day from our aquifers, lakes, rivers, and oceans to cool thermoelectric power plants in the US. This water withdrawal represents 48 percent of total water withdrawals in the United States.

Clean water is one of our most precious resources and it is at risk. Government agencies from around the world are reporting that we are on the verge of a worldwide water crisis. Global climate change, pollution, inefficient irrigation methods, and population growth are the most common contributing factors we hear about when this crisis is discussed. But the generation of electricity using a thermoelectric power plant is also a significant factor contributing to this crisis and a negative externality that should not be dismissed.

Water demand is expected to continue to increase at twice the rate of population growth. A big part of this increase is being created by the demand for water to cool more power plants. In the next seven years India, China and the U.S. plan to build 750 new coal-fired power plants. Another 340 coal plants are also planned throughout the world in the same timeframe. And with the Federal Energy Bill now passed, new power plants, including the possibility of a new generation of nuclear plants, are expected to be built.

The generation of electricity using nuclear energy consumes the most water - 0.62 gallons per kWh. Coal power plants use 0.49 gallons per kWh and a combined cycle natural gas power plant uses 0.25 gallons per kWh. Thermoelectric power plants withdraw 39 billion gallons of clean drinking water from our aquifers every day (20% of total water withdrawals). This is the equivalent to the daily drinking water requirements of 62 billion people, about 10 times the Earth's population.

As the demand for water increases, competition for water resource will continue to escalate and it will most likely result in local and regional conflicts. Communities downstream from many of these power plants will have less water available for their crops and for drinking. More conflicts will arise within communities to determine water use priorities.

Today, water rights are significant issues in the US, Israel, China, Africa and many other countries. Ismail Serageidin, a Vice President at the World Bank, said, "If the wars of the 20th century were fought over oil, the wars of the next century will be fought over water". And that doesn't mean armed conflicts over oil, coal, natural gas and access to nuclear materials will diminish either.

Renewable energy offers a multi-pronged solution. Using renewable energy and embarking on intensive conservation programs can significantly reduce the demand for water. Depending on location, a 100-watt solar panel will save 2,000-3,000 gallons of water over the 25-year warrantee life of the panel. All that water can stay in the aquifer until the next generation needs it.

Aquifers are being drained at a record pace, putting the supply of abundant and clean drinking water at great risk. Today, over one billion people around the world do not have access to clean and safe drinking water, and the number of people facing this crisis is increasing. First-world nations like the U.S. will not always be insulated from this dilemma.

All too often, the water-saving angle is a forgotten benefit of renewable energy. We know solar, wind energy, and other renewable energy technologies provide sustainable, clean sources of power. And it's now becoming abundantly clear to even the most skeptical that renewable energy technologies can be real engines of economic change, and provide some level of geopolitical security through increased energy independence. It's time to make sure that water conservation joins the growing list of reasons to mobilize a real and widespread shift to renewable energy.