UN-Water Facts about Energy and Water

Energy and water are inextricably linked – we need “water for energy” for cooling, storage, biofuels, hydropower, fracking etc. We need “energy for water” to pump, treat and desalinate. Without energy and water we cannot satisfy basic human needs, produce food for a rapidly growing population and achieve economic growth.

And yet, today, 1.3 billion people lack access to electricity and some 800 million people get their water from unimproved sources. Many more consume water that is unsafe to drink. These are mostly the same billion poor, hungry and underprivileged human beings. Over the coming 30 years food and energy demands are expected to increase dramatically, yet we will depend on the same finite and vulnerable water resource as today for sustaining life, economic growth and our environment.

  • Hydroelectricity is the largest renewable source for power generation and its share in total electricity generation is expected to remain around 16% through 2035.
  • Most of the water used for hydropower generation is returned to the river though some evaporates and there are important impacts on timing and quality of streamflows.
  • Roughly 75% of all industrial water withdrawals are used for energy production.
  • For developing countries alone $103 billion per year are required to finance water, sanitation and wastewater treatment through 2015.
  • Energy is required for two components of water provision: pumping and treatment (before and after use).
  • Waterborne transit is one of the most energy efficient. Inland towing barges are more than 3 times more energy efficient than road trucks and 40% more efficient than rail.
  • In Stockholm, public buses, waste collection trucks and taxis run on biogas produced from sewage treatment plants.
  • In 2011, 768 million people did not use an improved source of drinking-water and 2.5 billion people did not use improved sanitation.
  • More than 1.3 billion people still lack access to electricity, and roughly 2.6 billion use solid fuels (mainly biomass) for cooking.
  • Wind power is the most sustainable source of renewable energy, mainly because of its low greenhouse gas emissions and water consumption.
  • 90% of power generation is water-intensive.
  • There is an increasing risk of conflict between power generation, other water users and environmental considerations.
  • Energy production accounts for roughly 15% of all water withdrawals, or roughly 75% of all industrial water withdrawals.
  • Thermal power generation accounts for roughly 80% of global electricity production and is responsible for roughly one half of all water withdrawals in The United States and in several European countries.
  • Several factors determine how much cooling water is needed by thermal power plants, including the fuel type, cooling system design and prevailing meteorological conditions. However, efficiency is often the main factor that drives water requirements: the more efficient the power plant, the less heat has to be dissipated, thus less cooling is required.
  • Hydroelectricity, which can also require abundant water supplies, accounts for about 15% of global electricity production.

By 2035, global water withdrawals for energy are expected to increase by 20%, whereas water consumption for energy is expected to increase by 85%.