Exploring the interdependence of two critical resources

Two critical, interdependent resources

Energy supply depends on water. Water supply depends on energy. The interdependency of water and energy is set to intensify in the coming years, with significant implications for both energy and water security. Each resource faces rising demands and constraints in many regions because of economic and population growth and climate change.

Climate change will only increase the water crisis - clean energy can help

Nearly two-thirds of the world’s population experiences severe water scarcity for at least one month each year, and climate change will make water flows more erratic.

In the Net Zero Emissions by 2050 Scenario (NZE) water withdrawals by the energy sector decline by almost 20 bcm by 2030. The biggest reductions happen in the power sector, where withdrawals fall nearly 15% as coal-fired power generation is quickly replaced by solar PV and wind. Greater energy efficiency also plays an important role in reducing the volume of water needed to meet global energy demand.

Energy is thirsty

The world has a water problem – and the energy sector needs to contend with it. About a quarter of the global population does not have access to safe drinking water and almost half lack proper sanitation services. Nearly two-thirds of the world’s population experiences severe water scarcity for at least one month each year, and climate change will make water flows more erratic.

At the same time, the global energy system used around 370 billion cubic metres (bcm) of freshwater in 2021, or roughly 10% of total global freshwater withdrawals. Water is essential for almost every aspect of energy supply, from electricity generation to fossil fuel production to biofuels cultivation.

World Water Day is an annual event aimed at bringing attention to sustainable water management and this year’s theme is “accelerating change”. This commentary explores how an acceleration in clean energy development can help ease the world’s water crisis. The choices we make for future energy pathways will have a major impact on our ability to achieve Sustainable Development Goals, including access to clean water and sanitation for all.

Low-carbon doesn’t necessarily mean low water

Thermal power plants running on coal or gas are huge consumers of water, but even the fuels or technologies used to achieve the clean energy transition could, if not properly managed, increase water stress or be limited by it. Around the world, droughts have caused hydropower plants to curtail output. Some low-carbon technologies, such as wind and solar PV require very little water, others, such as biofuels, concentrating solar power (CSP), carbon capture, utilization and storage or nuclear power are relatively water-intensive. And nascent technologies such as using electrolysis to produce so-called "green" hydrogen are big water users.

An integrated approach focused on tackling climate change, delivering energy for all and reducing the impacts of air pollution (Sustainable Development Scenario) could result in lower water withdrawals in 2030 relative to today and other scenarios thanks to the increased deployment of solar PV and wind, a shift away from coal-fired power generation and energy efficiency.