Water shortages threaten future global power supply
More than 60% of the world's power stations could have their output affected by climate change-related water shortages, according to a new study published in the Nature Climate Change journal.
Researchers from the International Institute for Applied Systems Analysis (IIASA) in Austria analysed data from 4,500 hydropower and 1,500 thermoelectric power plants – including nuclear, and traditional fossil-fuel powered plants.
When factoring in projected temperature rises and associated water shortages, the researchers predicted that more than 60% of the plants would be forced to reduce capacity between 2040 and 2069.
Freshwater is used largely in power stations for its cooling capacity, as well as being converted into steam to generate electricity.
Coal and nuclear generation are particularly water-intensive, with 168 cubic meters of water withdrawn per MWh for nuclear power and 86 cubic meters per MWh for coal power plants.
Hydropower and thermoelectric power stations account for 98% of global electricity production.
“This is the first study of its kind to examine the linkages between climate change, water resources, and electricity production on a global scale,” explained study co-author Keywan Riahi.
“We clearly show that power plants are not only causing climate change, but they might also be affected in major ways by climate.”
Riahi said the most vulnerable regions were the US, southern South America, southern Africa, central and southern Europe, Southeast Asia and southern Australia.
In the US for example, 41% of all freshwater withdrawals are for thermoelectric cooling, more than in any other sector including agriculture.
Previous studies have predicted that a 50% rise in water demand by 2030, driven by electricity generation, could create a 40% gap between supply and demand in some parts of the world.
The IIASA study also explored the potential impact of adaptation measures, finding that efficiency upgrades and new cooling systems using seawater or air could help mitigate the problem.
The International Renewable Energy Agency (IRENA) has previously suggested that the best solution to the problem would be to increase renewables capacity.
The agency found that the UK is projected to withdraw 20bn cubic metres of water for power generation in 2030, but this could be cut to 9.7bn if the UK generates 60% of its electricity from renewables, with scaled-up solar PV and wind at the forefront.