A new study from EBG Capital and the World Policy Institute may have the energy industry, policymakers and environmentalists going back to the drawing board. For years now, the debate about energy and the environment has been about carbon emissions, how green various forms of energy are. This study asks how much water is utilized to produce that energy, how blue is it?
The authors note that “Energy production consumes significant amounts of water; providing water, in turn, consumes energy.” Until now, few have asked how much water is used and whether current energy production uses water wisely and effectively.
A pair of tables from the study suggest that the blue dimension will have us changing our view of various forms of energy. The first shows how much water is needed to run an 18,000 BTU air conditioner for 12 hours a day for one week:
Hydroelectric Minimal to 2,000 gallons
Geothermal 700 gallons
Solar Thermal 400 gallons
Nuclear 300 gallons
Thermoelectric, coal 200 gallons
Thermoelectric, oil 200 gallons
Thermoelectric, natural gas 100 gallons
Coal IGCC 100 gallons
(integrated gasification combined cycle)
Wind Minimal
Solar PV Minimal
The second table shows how much water is needed to drive from New York to Washington, DC (about 200 miles consuming 2 million BTUs:
Natural gas (as on land) 5 gallons
Unconventional natural gas (shale) 30 gallons
Oil (traditional) 28 gallons
Oil sands (mining) 550 gallons
Biofuels (irrigated corn) 32,000 gallons
Biofuels (irrigated soy) 89,000 gallons
Suddenly, green sources like nuclear and biofuels look far less attractive because they aren’t very blue. Solar-thermal looks far less attractive than photo-voltaic solar, and natural gas may emerge as the best compromise.