It’s an easily forgotten necessity of energy production: the billions of cubic meters (BCM) of freshwater that is necessary for cooling, irrigating, fracking, and other uses. This is water that is not returned to the water basin for future use — it’s temporarily lost to evaporation, consumption, or pollution.
The International Energy Agency expects energy industry water consumption to double from the 66 BCM used today to about 135 BCM by 2035.
The IEA predicts that more than half of that 135 BCM consumption will be due to coal-fired power plants, along with 30% used in biofuel production.
To imagine what 135 BCM looks like, the IEA equates it to 90 days’ discharge of the Mississippi River or four times the volume of Lake Mead. No drop in the bucket, friends.
Water pulled in all directions
As water is needed for increasing energy needs, water is also needed for an increasing population. To make matters worse, there’s concern over how robust the water supply will be in the coming decades as rainfall is less reliable and predictable thanks to climate change. Dwindling water supplies will affect agriculture, population distribution, and political stability.
How to sidestep excessive water usage
Increased reliance on wind and solar photovoltaic — which are decidedly less water hungry than coal and biofuels — will drastically reduce water usage. According to Think Progress, the IEA calculates that “wind and solar photovoltaic power have such minimal water needs they account for less than one percent of water consumption for energy now and in the future, by IEA’s calculations.”
Check out these tables of water use efficiency for conventional power plants versus wind and solar technology derived from 2010 data.
However, the big loser of renewable energy water consumption is concentrating solar thermal power. The misfortune is that wet-cooled concentrating solar power plants use a lot of water to make power. Like coal-fired power plants, to reduce water consumption at concentrating solar thermal power plants, dry-cooling technology should be implemented, but this can be quite costly.
Source: Think Progress