Cooling power plants with brackish groundwater is a topic that entails investigating alternative and sustainable cooling methods for power generation facilities. The cooling process is critical for power plant efficiency because it helps dissipate heat generated during electricity production. Traditional cooling methods frequently involve the use of freshwater; however, as water scarcity becomes a global concern, researchers are investigating the feasibility of using brackish groundwater as an alternative.
Nontraditional water sources can be used to help cope with climate-induced water risks and meet rising water demand for decarbonization of fossil-fuel-fired power plants, but this could raise electricity generation costs by 8% to 10%.
A new study led by a University of Wyoming researcher finds that brackish or salty groundwater has the potential to replace fresh water in cooling coal and natural gas-fired power plants and strengthen energy infrastructure resilience, though there is a cost to doing so.
Water competition between the electric power sector and other sectors is increasing as freshwater supplies are threatened by drought, climate change, and rapid socioeconomic growth. While transitioning to a low-carbon energy future, carbon capture and storage decarbonization of fossil fuel-fired power plants would significantly increase water consumption and exacerbate water competition. Water scarcity forces power plant operators to investigate alternative water sources.
Nontraditional water sources can be deployed to help cope with climate-induced water risks and tackle the increasing water demand for the decarbonization of fossil fuel-fired power plants. Treatment of brackish groundwater for thermoelectric generation cooling can help alleviate potential competition for freshwater resources among various sectors in water-stressed regions.
Haibo Zhai
“Nontraditional water sources can be deployed to help cope with climate-induced water risks and tackle the increasing water demand for decarbonization of fossil fuel-fired power plants,” wrote the research team, led by Haibo Zhai, UW’s Roy, and Caryl Cline Distinguished Chair in the College of Engineering and Physical Sciences. “Treatment of brackish groundwater for thermoelectric generation cooling can help alleviate potential competition for freshwater resources among various sectors in water-stressed regions.”
The study was published in the journal Nature Water, with Zhai’s UW Ph.D. student Zitao Wu as the lead author. The National Energy Technology Laboratory in Pittsburgh, Pa., also contributed. This journal publishes the most innovative research on the changing relationship between water and society. It’s the second paper in a multiyear project funded by the US Department of Energy; the first, published last year in the journal Applied Energy, looked at the possibility of switching from water cooling towers to dry cooling systems at fossil-fuel-fired power plants.
Removing excess dissolved salts and minerals from brackish water can be energy-intensive and result in concentrated brines that must be disposed of. A method known as zero liquid discharge reduces the environmental impact of desalination but is particularly expensive.
The scientists investigated the technical and economic feasibility of various desalination processes. They also calculated how much fresh water would be saved by treating brackish water for power plant cooling, and they assessed the cost-effectiveness of brackish water treatment retrofits – as well as the impact on power plants’ net generating capacity. They concluded that retrofitting power plants to treat brackish groundwater could nearly eliminate the use of fresh water while raising electricity generation costs by 8% to 10%.
“Our study reveals trade-offs in freshwater savings, cost and generating capacity shortfalls from desalination deployment,” according to Wu.
The researchers advocate for the further development of technologies to treat brackish water, as well as the investigation of other nontraditional water sources for power plant cooling. These include treated municipal wastewater, oil and gas extraction water, and carbon dioxide storage reservoirs.
According to the researchers, the trade-offs identified for various nontraditional water sources will fill knowledge gaps to better inform water-for-energy decisions and management.
