Hydropower's evolving role in climate mitigation and adaptation
Changing water flows
One of the clear impacts climate change is having on the hydropower sector is a significant increase in drought and floods. It is vital that the sector builds in resilience to these changes to ensure that dams can continue to operate safely.
The World Meteorological Organization reports that drought conditions caused a significant drop in hydropower production in 2022.
Droughts and heatwaves already affect around 25-35% of global GDP, as well as 1.5 billion people. By the end of the century, there will be an additional impact of US$20 trillion (in 2015 dollars) and 1.7 billion people. Of these people, 600 million will be affected by medium to severe droughts. Whilst the future impacts on hydropower production are uncertain, hydropower is among the best ways to mitigate droughts.
IHA estimates that through the water storage function of its reservoirs, the hydropower industry prevents US$131.3 billion in annual GDP losses from drought incidents. Increased water volatility worldwide will see the potential for hydropower to generate electricity grow in the next 30–70 years, with different regions affected in different ways.
In some regions, like South America, there will be a reduction in the potential due to lower water levels. However, in others, such as South and East Asia, there will be a surge in hydropower’s energy production due to higher volumes of water.
It is not just drought and flooding that are causing hydrological variability. There is growing water demand from the agriculture and industry sectors. This means that current gross water demand has increasingly seen a shortfall in supply from rivers, lakes and reservoirs and renewable groundwater. The world needs to manage its supplies of water carefully, which will require more and not less water infrastructure.
Flood damage prevention
This is where hydropower plays a crucial role in climate adaptation. Reservoirs provide a buffer against extreme weather events such as floods. By regulating river flow and thus reducing peak flows, reservoirs can reduce the risk of downstream flooding.
This protects lives, property and critical infrastructure. Given the need for more water management infrastructure, these developments should be powered where possible.
Hydropower does not preclude the water being used for other purposes such as irrigation, sanitation or drinking water supply. Water use should be considered at a system level.
A future power mix largely dependent on wind and solar, with hydropower providing complementary flexibility and stability, will use less water than the current mix. This is due to the avoidance of heavy water use by fossil-fuelled generators.
According to the International Energy Agency (IEA), delivering the net zero emissions by 2050 scenarios would mean a significant decline in water withdrawals by the energy sector, with a reduction of almost 20 billion m3 by 2030. This equates to the annual level of water consumption by fossil fuels in 2021.
Responding to climate risks
The hydropower industry has responded to the pressing need for climate resilience through improving the resilience of civil infrastructure and improving sediment management to protect power generation from further decline.
Central to this endeavour is the Hydropower Sector Climate Resilience Guide, a comprehensive resource designed to navigate the complexities of climate adaptation.
This guide serves as a strategic tool for hydropower projects. It offers insights into climate risk assessment, adaptation strategies and resilience-building measures.
Its applicability is wide-ranging. It caters to any type and scale of hydropower project, both existing and future. It is of use to single and cascade projects, irrespective of geography.
IHA is working to update and adapt the guide with the Hydropower Sustainability Alliance. A new version of the guide will be published in 2024.
