Without energy and electricity production in society, day to day living would be difficult.
What some people don’t know is that energy/electricity production & water are linked very closely – you need water to produce energy, and energy is used to deliver us fresh water.
In this guide, we look at how much water the various energy/electricity production sources need i.e. what their water footprint is.
How Electricity Generation Uses Water
- In most power plants, water cools the steam that spins the electricity-generating turbines.
- Almost all major sources of electricity rely to some degree on water. Most power plants generate heat from their fuel (by burning coal or natural gas, for example, or by maintaining a fission reaction), and use that heat to boil water, produce steam, and turn turbines.
- Water is also used during various stages of energy-related resource extraction, processing, and waste disposal.
– ucsusa.org (read more about how the different electricity generation methods require and use water at https://www.ucsusa.org/clean-energy/energy-water-use#.XF6IaeIzbR1)
You can also further read how power plants use water at https://www.watercalculator.org/water-use/the-water-footprint-of-energy/
- Water usage is one of the most obvious environmental impacts of electricity generation.
- All thermal cycles (coal, natural gas, nuclear, geothermal, and biomass) use water as a cooling fluid to drive the thermodynamic cycles that allow electricity to be extracted from heat energy.
- Other energy sources such as wind and solar use water for cleaning equipment, while hydroelectricity has water usage from evaporation from the reservoirs.
How Much Water Electricity Uses In The United States Every Year
Read more at https://www.watercalculator.org/water-use/the-water-footprint-of-energy/. They also discuss other environmental impacts, such as the impact on wildlife.
Important notes are:
- Because of the large amount of water required by thermoelectric plants, total US withdrawals for thermoelectric power accounted for 41 percent of total water withdrawals in 2015 (the most recent year data is available).
- That added up to 133 billion gallons per day, most of which were from surface water sources and 72 percent of which were from freshwater sources like lakes and rivers.
- Power plants that used once-through cooling systems accounted for 96 percent of all withdrawals for thermoelectric power.
Water Footprint Of Different Energy/Electricity Production Sources
The water use by power plants, in terms of water consumed to produce one megawatt hour of electricity (which is enough to power 1000 homes) is:
- Solar thermal with wet cooling – 786 gallons
- Coal – 687 gallons
- Nuclear – 672 gallons
- Natural gas – 198 gallons
- Solar photovoltaic – 26 gallons
- Solar thermal with dry cooling – 26 gallons
- Wind – 0 gallons
As a side note – Roughly 90 percent of the energy [the US used in 2013 came from] nuclear or fossil fuel power plants.
- Coal, nuclear and natural gas plants use enormous amounts of steam to create electricity. Producing all of that steam requires 190,000 million gallons of water per day, or 39% of all freshwater withdrawals in the nation [as of 2013]
- Using renewable energy technologies such as wind and photovoltaics means doing away entirely with water use for electricity production
- [one piece of research studied the] water-efficiency of some of the most common energy sources and power generating methods
- … 11 types of energy sources, including coal, fuel ethanol, natural gas, and oil; and five power generating methods, including hydroelectric, fossil fuel thermoelectric, and nuclear methods
- … [the most water efficient energy sources in gallons of water per British Thermal Unit (BTU) are] natural gas and synthetic fuels produced by coal gasification … [and] The least water-efficient energy sources are fuel ethanol and biodiesel
- … in terms of power generation … geothermal and hydroelectric energy types use the least amount of water, while nuclear plants use the most.
- [what is interesting is] burning a compact fluorescent bulb for the same amount of time [as an incandescent one] would save about 2,000 to 4,000 gallons of water per year
- [results should be taken lightly because] several variables such as geography and climate, technology type and efficiency, and accuracy of measurements that come into play. However, by standardizing the measurement unit, we have been able to obtain a unique snapshot of the water used to produce different kinds of energy
- More water usage stats broken down by energy source can be found at https://en.wikipedia.org/wiki/Environmental_impact_of_electricity_generation
How To Reduce Water Footprint In Energy/Electricity Production
- Retrofit existing coal power plants with new water efficient systems and technology could double water efficiency
- Use more water efficient energy sources like solar and wind in the future for our energy