If there’s one message that the United Nations wants to drive home this World Water Day, it’s this: Water requires energy, and energy requires water.
It’s called the energy-water nexus, and it’s the focus of this year’s World Water Day, a United Nations-designated day focused on raising water awareness and promoting positive water policy. The energy-water nexus emphasizes the interdependence of water and energy.
On one hand, water is crucial to produce energy – it’s heated through solar arrays, employed to produce fuels such as coal and oil, and massive water resources are needed to cool nuclear power systems. Overall, about 90 percent of power generation is water-intensive.
On the other hand, a surprising amount of energy is consumed just to pump, treat and transport water – about 8 percent of global energy production, in fact. Energy is needed to irrigate fields, to truck clean water to places that need it, and it’s necessary to process wastewater before it is discharged back into the environment.
With already increasing pressure on limited water resources, a demand for nontraditional water-intensive energy sources could further threaten this fragile balance. For example, unconventional oil and gas production (such as tar sands and fracking) are more water-intensive than conventional means.
At the same time, the rate of groundwater abstraction – removing water from its source – is increasing 1 to 2 percent per year, and an estimated 20 percent of the world’s aquifers are already over-exploited. By 2035, the world’s energy consumption will increase by 35 percent. This will raise water consumption by 85 percent, says the International Energy Agency.
As the World Bank reported, water shortages in 2013 shut down thermal power plants in India, drove down energy production in United States power plants and threatened hydropower in Sri Lanka, China and Brazil.
“The world’s energy and water are inextricably linked,” said Rachel Kyte, World Bank Group Vice President and Special Envoy for Climate Change. “With demand rising for both resources and increasing challenges from climate change, water scarcity can threaten the long-term viability of energy projects and hinder development.”
Therefore, securing water and energy must be central in the development of Sustainable Development Goals (SDGs) – development objectives set to build upon the 2015-targeted Millennium Development Goals.
As the UN highlights, “the challenge for 21st century governance is to take account of the multiple aspects, roles and benefits of water, and to place water at the heart of decision-making for all water-dependent sectors, including energy.”
March 22 is World Water Day – remember this: Saving energy is saving water; saving water is saving energy.