Water Consumption of Solar Thermal Power Plants

Nuclear industry advocates active in a South Australian community forum claim that the water use of Solar Thermal Power Plants is extremely high, in fact too high to be viable either now or into the future.

We have seen that ” In 2008, nuclear power plants withdrew 8 times as much freshwater as natural gas plants per unit of energy produced, and up to 11
percent more than the average coal plant.” (Source: ii Averyt, et al. Freshwater use by U.S. Power Plants: Electricity’s Thirst for a Precious Resource. Union of Concerned Scientists, EW3, 2011.) and:

Regarding nuclear power plants: “once-through cooling systems withdraw 25,000 to 60,000 gallons of water for each megawatt-hour of electricity produced, recirculating cooling systems, also known as closed-cycle cooling systems, withdraw only 800 to 2,600 gallons per megawatt-hour and are used when nearby water sources lack sufficient volume to allow once-through cooling. After water is withdrawn from a source to cool steam, it is then cooled and pumped back into the condenser for reuse. Though plants with closed cycle cooling systems withdraw far less water than once-through cooling systems, they consume (through evaporation) about 600-800 gallons per megawatt-hour, roughly half the amount they withdraw.” (Source: Union of Concerned Scientists) further:

“Other water uses for nuclear power
While cooling systems account for the vast amount of water
withdrawn by nuclear power plants, fuel extraction and refining have
also impacted water sources. Uranium fuel extraction, for example,
requires 45-150 gallons of water per megawatt-hour of electricity
produced and uranium mining has contaminated surface or ground
water sources in at least 14 states.” (Source: UCS. EW3. 2011) Additionally:

“Additionally, nuclear power plants
intake water to cool service equipment, such as chillers for air
conditioning units or lubricating oil coolers for the main turbine.
Service water system flow rates can range from 13,500 to 52,000
gallons per minute depending on the season and the power plant” (source: UCS. 2007)

More information regarding NPP water consumption at : https://nuclearexhaust.wordpress.com/2018/03/25/water-consumption-of-nuclear-reactors/ , the primary source document for which is: Union of Concerned Scientists at https://www.ucsusa.org/sites/default/files/legacy/assets/documents/nuclear_power/fact-sheet-water-use.pdf

So, is the nuclear industry correct in its assertion that solar thermal electricity production is not feasible as it will forces regions into prolonged water shortage and worse?

Source Link:

Journal of Contemporary Water Research & Education
© Universities Council on Water Resources

Water Requirements for Large‐Scale Solar Energy Projects in the West
George B. Frisvold Tatiana Marquez
First published: 3 February 2014 https://doi.org/10.1111/j.1936-704X.2013.03156.x


“This study estimates how much water would be required to meet Renewable Portfolio Standards for electricity generation in five western states if 100 percent of this demand were supplied by solar power. Future renewable electricity demand (net of current supplies) is estimated for 2025 and 2035. One scenario assumes the most water‐intensive solar thermal technology supplies all this future demand. Although not a feasible scenario, the assumed water intensity (1057 gallons/MWh) provides an upper‐bound estimate of solar power water consumption that may be compared with regional water balances. A second scenario assumes the water intensity of future projects is comparable to the average of solar projects actually being deployed. Water intensity for these 34 projects with 8.7 GW of capacity averages 228 gallons/MWh – a lower rate than many conventional electricity facilities (i.e., coal, natural gas, nuclear). Water requirements by 2035 would be 0.8 percent of regional consumptive use of water under the upper bound scenario and 0.2 percent of consumptive use based on current, average water intensities.” end quote.

So according to the sources above, nuclear once through cooling uses up to 60,000 gallons per MW generated. Nuclear closed cycle nuclear cooling system uses up to 2,600 gallons per MW generated. Additional water use at the plants and in mining and preparing the nuclear fuel consumes up to an additional 52,000 gallons of water per minute.
Nuclear best case: up to 52,000 gallons per MW
Worst case: 60,000 gallons per MW
Additional consumption adds substantially to the total water consumption of nuclear industry.

By contrast the worst case for a solar thermal power plant based energy supply is 1057 gallons/MWh. The realistic prediction of a solar powered grid is for water consumption to average 228 gallons per MWh generated.

This results in NPPs with single pass cooling systems using about about 56 times the water consumption of a Solar Thermal power plant.

Solar Thermal uses about 2.5 times less water per MW than an NPP with a closed cycle cooling system.