Power plants struggle in the heat, Ukraine has a solution

This summer's heatwaves have put our energy infrastructure to the test. From overheating nuclear reactors to wind turbines standing still in wind droughts, extreme heat is an energy challenge we can't afford to take lightly. Low water levels in rivers are the main problem, since they affect most power plants. Whether gas-powered, coal-fired, or nuclear; all rely on rivers' levels being high enough to feed their cooling systems. There are also limits for how much hot water used for cooling can be sent back into the rivers without killing fish and causing harm to the local environment. During extreme heat, power plants often have to reduce their energy output to comply with these regulations. That's a problem, particularly with big nuclear power plants that play a central role in the energy systems of several European countries. In Hungary, the Paks nuclear power station, which normally covers about 40% of the country's electricity needs, was on the brink of a complete shutdown in August because of the Danube running dry. Earlier this month, Budapest already introduced electricity-saving measures following the drought. Romania has been facing similar issues. France, a country that runs mostly on nuclear power, had to shut down three out of its 57 nuclear reactors and reduce the output of another seven in July, leading to an overall 9% dip in electricity generation. All of this comes at a time when demand for electricity is surging, with people turning up their air conditioners and fans to cope with the heat. During June's heatwave alone, power consumption in France jumped by 20%. When France stops exporting its otherwise relatively cheap nuclear power to ensure supply to its local market, it pushes prices up across Europe, particularly in countries like the UK, Germany, or Italy, that are among France's main energy customers. The most recent heat wave caused a 20% spike in power prices. As the climate crisis escalates, heat waves like the ones we've felt this summer are likely to become an ever-more frequent phenomenon. Our energy infrastructure needs to adapt, or it can easily get paralysed. Solar power stands out as a key power source performing reliably in extreme heat, helping to fill in the gap. Still, the adaptation of nuclear facilities will be crucial for many European countries. Ukraine is already leading the way: despite Russia’s attacks on its energy infrastructure, Ukraine’s nuclear plants have proved remarkably resilient to extreme heat. Unlike French, Hungarian, and Romanian nuclear plants, Ukraine’s plants have kept running without heat-related reductions, according to state operator Energoatom and the Ukrainian Nuclear Society. Much of the difference comes down to how they guarantee water supply for cooling. While many European nuclear plants draw it directly from rivers, Ukraine has implemented a variety of cooling systems that make its plants less vulnerable to water scarcity. Khmelnytskyi and South Ukraine nuclear plants, for instance, use dedicated cooling reservoirs that rely on closed-loop water cooling systems. Rivne relies heavily on cooling towers that remove heat through evaporative cooling. Zaporizhzhia, currently under Russian occupation, was also designed around a large artificial cooling pond. Ukraine certainly did not build its nuclear fleet with today’s climate crisis in mind. Yet some of those old design choices are showing the rest of Europe how to increase their plants' resilience.