Energy and water have always been closely intertwined; water is needed for all phases of energy production and energy is critical to water supply, wastewater treatment and desalination. How this nexus is managed is critical for the energy community as it has implications for the transition to a low carbon pathway, energy security and the attainment of the Sustainable Development Goals (SDGs).
Analysis by the International Energy Agency (IEA) found that the energy sector withdraws around 340 billion cubic meters (bcm) of water—defined as the volume of water removed from a source—and consumes roughly 50 bcm—the volume that is withdrawn but not returned to the source. This amounts to 10 percent of total global water withdrawals and 3 percent of consumption. While the energy sector’s share is relatively low, global water demand could increase by 30 percent by 2050 (UN Water, 2019).
On the other side of the energy-water equation, the IEA found that the water sector uses almost as much energy as Australia. Most of this is in the form of electricity—850 terawatt-hours (TWh) primarily for water supply and wastewater treatment—and represents around 4 percent of global electricity consumption. In addition, some 50 million tons of oil equivalent of thermal energy is used for desalination and diesel pumps for irrigation.
With both energy and water demand on the rise, it is increasingly important to understand the water-energy nexus in order to avoid unintended consequences, anticipate stress points and implement policies, technologies and practices that soundly address associated risks and maximize synergies.