IRENA assesses Czech August energy sector battered by drought

This year’s August heatwave on the Danube showed what happens when an energy mix relies too heavily on a single source. According to a new analysis by the International Renewable Energy Agency (IRENA), output at Hungary’s Paks nuclear power plant fell to as little as nine percent of installed capacity due to a lack of cooling water, while Romania’s Cernavodă was completely shut down for one day. 

Most thermal power plants – nuclear, coal-fired and combined-cycle gas – operate on the principle of a steam cycle, which requires a cooling circuit. Once-through cooling draws large volumes of water from rivers, lakes or the sea. During droughts, water levels and flows decline, while the water also warms up, and legislation then limits how much heat a power plant may discharge back into the watercourse.

IRENA identified 207 inland thermal power plants in Europe with a combined capacity of 154 GW, located within ten kilometres of a major river. Nearly a third of these are nuclear facilities. Twenty-seven of them are located on the Danube.