If the energy sector is to tackle climate change, it must also think about water

The energy sector is a key contributor to climate change, accounting for more than two-thirds of global greenhouse gas emissions. It is also directly impacted by climate change, with many of the impacts manifesting themselves through water—a fact highlighted by this year’s World Water Day

In the run-up to a crucial COP-26, the IEA is highlighting ways to reduce the energy sector’s contributions to greenhouse gas emissions while also shoring up its resilience to the impacts of climate change. Both of these goals will require an understanding of the water-energy nexus in order to avoid unintended consequences, anticipate stress points and implement the policies, technologies and practices that lead us on a path to a more secure and sustainable energy future.

To ensure this year represents a lasting peak in emissions, industry and governments need to accelerate efforts to deploy the technologies and solutions that bring near-term emission reductions at scale. However, the fuels or technologies used to achieve this transition could if not properly managed, exacerbate or be limited by water stress depending on the location, availability of water and competing users. Technologies such as wind and solar PV require very little water, but others like biofuels, concentrating solar power (CSP), carbon capture, utilization and storage or nuclear power can have more significant water demands. This underscores the importance of factoring water use into energy policy decisions.

Given this, the IEA assessed the future water needs of rapid energy transitions as envisaged by its Sustainable Development Scenario — an integrated approach focused on tackling climate change, delivering energy for all and reducing the impacts of air pollution. In such a scenario water withdrawals — defined as the volume of water removed from a source — are 20% lower than today. The increased deployment of solar PV and wind, a shift away from coal-fired power generation and a greater focus on energy efficiency all contribute to this decline. However, the energy sector’s water consumption moves in the opposite direction in this scenario — increasing by 50%. Though water withdrawals are the first limit for energy production when water availability is constrained, water consumption — the volume that is withdrawn but not returned to the source — reduces the overall amount of water available to satisfy all users. While this will not be an issue in all areas, taking steps to improve power plant efficiency, deploying advanced cooling systems, and making better use of non-freshwater and water recycling can all help ensure that decarbonisation plans are water smart.

Global water use in the energy sector by fuel and power generation type in the Sustainable Development Scenario

Global water consumption in the energy sector by fuel type in the Sustainable Development Scenario, 2016-2030


Global water withdrawal in the energy sector by fuel type in the Sustainable Development Scenario, 2016-2030


Beyond just understanding how our energy choices impact water resources, we need to better understand and plan for how water-related climate impacts will affect the energy sector. Water scarcity is already having an impact on energy production and reliability; further constraints may call into question the physical, economic and environmental viability of future projects- something the IEA will assess in a major forthcoming report on electricity security. On the other side, diminished freshwater resources can lead to a greater reliance on energy-intensive sources of water supply such as desalination. Each of these have potential implications for energy security.

Many countries already face some degree of water stress; and there is increased uncertainty about future water availability and the impact that climate change will have on water resources. Climate change is expected to alter the frequency, intensity, seasonality and amount of rainfall as well as the temperature of the resource- impacting both energy and water infrastructure.

Several countries may find that their plans to increase power generation in at least some parts of the country will be dependent on water availability. Droughts and water shortages have already affected India’s thermal power plants: India lost 14 terawatt-hours (TWh) of thermal power generation in 2016 due to water shortages. Rising temperatures may also mean some power plants are no longer able to comply with the temperature regulations for water discharge. As such, plans for power generation that rely on more water-intensive technologies will need to take into account current and future water availability in the choice of sites and cooling technologies, and, where possible, use alternative water sources.

Hydropower, which plays an important role in many countries’ decarbonisation plans, is especially vulnerable to climate impacts. In Africa, where hydropower accounts for 22% of electricity generation (compared to 16% globally), climate change has already affected the capacity of Zambia’s largest hydropower plant, leading to blackouts. In addition to being a key pillar of clean energy transitions, hydropower is also an important source of system flexibility that can enable higher shares of more variable renewables, something this year’s Renewables 2020 report will highlight. As such, understanding the climate risks and putting in place the technical and policy measures necessary to enhance the resilience of hydropower will be essential, something a forthcoming IEA report will assess in the context of Africa.

Rising water demand coupled with increasing uncertainty over water supply and diminishing water quality will increase the energy needed to move, pump and treat water. For example, more countries could turn to desalination to help narrow the gap between freshwater withdrawals and sustainable supply. In the Middle East desalination accounts for just 3% of the Middle East’s water supply today but 5% of its total energy consumption. By 2040 in our Stated Policies Scenario, desalination accounts for roughly a quarter of the region’s water supply and almost 15% of total final energy consumption. Using water more efficiently and tackling water losses from pipe leaks, bursts and theft can help mitigate the increase in energy demand and increase water availability.

Water does not have to be a limiting factor for the energy sector and a rise in water demand does not have to lead to a similar rise in energy demand. But unless energy and water are considered in tandem, we are unlikely to meet our energy transition and energy security goals.

For more on the IEA’s work on the water-energy nexus, visit the water and energy topic page.