The best information sources are often your readers.
I received an e-mail last week from Jim McGilligan, who has a degree in engineering from the University of Delware, who just came across this article on water and energy titled: "What is your water footprint?" published in the (Lafourche Parish, La.) Daily Comet. Written by Tom Rooney, president and CEO of SPG Solar in Novato, Calif the article is "the best I've ever seen" on this topic, Jim tells me.
The article raises the key points that we should consider water consumption and concern ourselves with the amounts of energy required to heat and cool water when looking at shrinking our carbon footprints i.e. 'water footprints'.
For most types of commercial electric power the story says you need water: to turn into steam i.e. coal, gas, nuclear, oil or to push turbines i.e. hydro. In the former grouping this water which must be cooled and reused rather than dumped into lakes, ponds, and streams, harming aquatic life.
While the articles doesn't mention this in the latter example i.e. hydro, water must be dammed, interfering with fish runs and turning farms and forests into eerie liquid landscapes, whose remains can be seen during low levels. There has been and continues to be costly efforts to provide for or restore salmon on rivers blocked by hydro projects.
The story says that it takes at least a gallon of water to create one kilowatt hour of power: enough to run your air conditioner for one hour.
It cites estimates from Rachelle Hill and Dr. Tamim Younos of Virginia Tech University that "fossil fuel thermoelectric plants use between ... 8 to 16 gallons of water to burn one 60-watt light bulb for 12 hours per day. Over the duration of one year this one incandescent light bulb would consume about 3,000 to 6,300 gallons of water."
"So we use water to create energy, and we use energy to create water -- to create more energy to create more water," says Rooney. "And on and on and on it goes in a downward spiral that completely distorts the way we think and act about water and power."
Rooney, perhaps not surprisingly given his company recommends using photovoltaic cells. While these solutions will not replace water-based power sources (not in my part of the world i.e. the Pacific Northwest where in winter the sun is that weird object we know is out there) he does call attention to the need to cut down on water use and on the energy consumption in turning water into energy. Not when we have other uses for that water i.e. drinking, to sustain life forms that we eat.
With growing populations and global warming that has led to droughts--and the Moon a little far away for a pipeline--we can't afford to waste that ultimately life-given commodity.