You already know that solar power reduces your energy bill and our dependence on fossil fuels, but did you know that going solar also saves water?
Water is used throughout traditional energy production: to pump crude oil out of the ground, remove pollutants from power plant exhaust, generate steam that turns turbines, flush residue after fossil fuels are burned, and cool power plants. In fact, fossil-fuel-fired thermoelectric power plants consume over 500 billion liters, or more than 132 billion gallons, of fresh water per day in the United States alone.
“The most important use of water for electricity production is for cooling,” says Adam Schlosser, an author of the study and the assistant director for science research at MIT’s Joint Program on the Science and Policy of Global Change. “The benefit of renewables like wind or solar is that you don’t need to boil water for steam to spin the turbines, and then you don’t need water to cool the steam. That cooling process is removed, saving a lot of water.”
According to the EPA, each kilowatt-hour (kWh) of thermoelectric generation requires the withdrawal of about 25 gallons of water, however only an average of 2 gallons of water is actually lost to evaporation for each kWh consumed.
If the average residential meter in Hawaii uses 615 kWh per month, that’s 1,230 gallons of water used in addition to your normal water needs. That may not seem like a big deal since that water use doesn’t show up on your water bill, but water consumption is something we all need to be aware of now – before water scarcity becomes a problem here in Hawaii.
The Hawaii Water Conservation Plan written in February 2013 shows that “over 90 percent of the state’s drinking water comes from groundwater sources, while much of the water used for agricultural irrigation comes from surface water sources. It is estimated that public water systems supply approximately 205 million gallons per day (mgd) of potable water across the state. Water used for agricultural irrigation is estimated to be well over 350 million gallons per day. In some areas of the state, demand for water is approaching the sustainable limits of supply, and these demands are expected to increase in the future. In order to sustain and protect our water for future generations, we must strive to be as efficient as possible in all of our water uses.”
Normally, when folks think about going solar, they’re thinking about their wallets, not the environment. When they do think about saving the planet with their solar panels, they’re probably happy about the incredible amounts of carbon pollution they’ll be avoiding by switching to clean energy. But now, you can add conserving water as one more reason to go solar.