The energy-water nexus
This chapter focuses on the energy-water nexus, with a particular emphasis on the electricity supply industry. That industry mostly uses what are called “thermoelectric” power plants to transform combustible fuels into usable forms of energy. These plants withdraw about 24.5 gallons of water per every kilowatt-hour (kWh) of electricity produced by diverting water from the water’s source; they consume another 0.5 gallons per kWh through evaporative loss. When taken collectively, they withdraw trillions of gallons of water from rivers and streams, and they consume billions of gallons of water from local aquifers and lakes. Other related energy systems, such as coal mining, oil and gas production, and uranium mining, also require millions of gallons of water to mine, collect, process, enrich, and clean fuel. And at each step, energy systems degrade water quality by altering its temperature, contaminating it with mercury and particulate matter, and shifting where it falls and flows through direct usage and indirectly induced climate change.