Hydroelectricity is a low-carbon and renewable energy source. Increasing the proportion of UK electricity generated from low-carbon energy sources can reduce the proportion that must be generated by higher-carbon sources.
The working life of a large-scale hydroelectric power station can exceed 100 years – so when we calculate the average lifetime emissions of a hydroelectric power station, initial CO2 emissions will be offset by subsequent decades of zero-carbon electricity generation.
In 2014, the UK generated around 1.9% of its energy from hydroelectric power stations, according to EDF Energy analysis based on Elexon data.
Smaller-scale run-of-river schemes that use the natural flow of rivers or streams to drive a turbine have a much smaller carbon footprint than large-scale schemes. Typically, they produce less than 5 grams of CO2 for each kilowatt-hour (kWh) of electricity they generate, because construction of a run-of-river project releases less CO2 than that of a hydroelectric power station.