A great irony of living on the ‘Blue Planet’ is that while over 70% of the Earth’s surface is covered in water, humans can only use less than one percent of it easily. As the world continues to develop economically, demand will increase for reliable access to energy and water. Countries increasingly recognise the need for energy security. However, the connection between energy and water is not as well understood or appreciated. The reality is that both energy and water are critical to human development and are strongly interrelated.Turning on the tap at home takes vastly more energy than a flick of the wrist. Water cannot be collected, purified, transported, heated, or treated without energy.In water-scarce California, where water is literally moved over mountains, producing usable water consumes a fifth of the state’s total electricity consumption.
In the United Arab Emirates, which obtains most of its usable water from purifying seawater, the costs of desalination are expected to increase by 300% between 2010 and 2016. Desalination also requires about ten times more energy than surface freshwater production and is rapidly increasing the demand for fossil fuels.Energy cannot be generated and distributed without water. 19% of global electricity is produced by hydroelectric facilities, whose generators are powered by water’s enormous kinetic energy.
In the US, the power sector is the largest user of water, withdrawing billions of gallons per day to cool nuclear, coal, natural gas, and biomass power plants. While most of this water is eventually returned to its source, power plant cooling still comprises 40% of all freshwater withdrawals, about the same as agricultural use. And though oil and water may not mix, the oil extraction and refining processes, on average, requires between three and six gallons of net water use for every one gallon of gasoline produced.
Global fresh water supplies are also impacted by rising income levels and population growth. Already about a billion people worldwide – one in six – lack reliable access to fresh water. Increasing affluence typically results in increased personal energy and water consumption. Water demand in the US has tripled over the last three decades and global water usage has been growing at more than twice the rate of population increase. Water consumption will only be compounded by continued population growth, especially in the developing world.
Extreme weather events will only exacerbate the challenge. More frequent and more severe droughts and floods can lead to shortages in water and energy in both developing and developed countries. Droughts lower dam levels and reduce output from hydro facilities. At the same time, floods can overwhelm water systems and prevent the treatment and distribution of clean water.