I didn’t raise any questions during Michael Webber’s talk on Wednesday, but I did consider raising the issue of water, or specifically the relationship between fresh water production and energy production. Whatever Texas’s advantages in energy production, they are somewhat mitigated by our disadvantages in water supply. If one agrees that water production and energy production are related issues, this obviously becomes relevant.
This raises a question which I did not put to Richard nor to Michael Webber but which has been puzzling me. Webber’s article makes it explicit:
We cannot build more power plants without realizing that they impinge on our freshwater supplies. And we cannot build more water delivery and cleaning facilities without driving up energy demand. Solving the dilemma requires new national policies that integrate energy and water solutions and innovative technologies that help to boost one resource without draining the other.
So here’s my question: why do power plants require fresh water? Is the dominant purpose of water not cooling? If not, why is water such a big issue? On the other hand, if cooling and quenching and thermal conduction is the issue, why use precious freshwater instead of sea water?
Note, the following appears in an information-poor infographic (that doesn’t make it into the scanned text) in Webber’s article:
Water Required to Generate One MW-hr
- Gas/Steam: 7,400-20,000 gallons
- Coal or Oil: 21,000-50,000 gallons
- Nuclear: 25,000-60,000 gallons