“Water availability is a growing concern for energy, and assessing the energy sector’s use of water is important in an increasingly water-constrained world” —IEA Executive Director Maria van der Hoeven
Tomorrow is officially designated “World Water Day” and this week, the IEA has been trying to raise awareness about the amount of water used to produce energy – on Twitter. The chart below is from the IEA’s World Energy Outlook 2012 PDF “Water for Energy – Is Energy Becoming a Thirstier Resource?”
Please take note of the fact that the bottom half of the chart relates to water requirements for producing biofuels, and also note the differences between the various biofuels water requirements. Especially, note the minimum for each biofuel, which is defined as “non-irrigated crops whose only water requirements are for processing into fuels.” (This chart should also help drive home the fact that using irrigated corn to produce ethanol is highly irrational and wastes a precious resource, something that should be corrected by policy – now.)
To follow, are some of the IEA’s tweets (and facts from the PDF linked above), (rewritten for clarity), that contain some very interesting statistics about water use in energy production:
It can take nearly 60 gallons of water to power a 60-Watt incandescent light bulb for 12 hours.
154.3 trillion gallons of freshwater are used in energy production per year.
Water requires energy, and energy requires water: Each kilowatt hour of electricity requires the withdrawal of approximately 25 gallons of water.
Energy depends on water for power generation, extraction, transport and processing of fossil fuels, and irrigation of biofuels feedstock crops.
Energy accounts for 15% of global water usage, and will consume ever more through 2035.
Global water withdrawals for energy production in 2010 were estimated at 583 billion cubic metres (bcm), or some 15% of the world’s total water withdrawals. Of that, water consumption – the volume withdrawn but not returned to its source – was 66 bcm. In the New Policies Scenario, withdrawals increase by about 20% between 2010 and 2035, but consumption rises by a more dramatic 85%. These trends are driven by a shift towards higher efficiency power plants with more advanced cooling systems (that reduce withdrawals but increase consumption per unit of electricity produced) and by expanding biofuels production. (source: PDF)
So, as we can see, the IEA’s anticipated increase in biofuels production between 2010 and 2035 accounts for a large share of the anticipated increased demand for water used to produce energy.
In the energy-food-water nexus, water is the member of that threesome that is increasingly grabbing the headlines. And, in my opinion, a more accurate description of the problem we face would be the energy-food-water-biofuels nexus.