Writing in the New Scientist, Carey W. King and Michael E. Webber of The University of Texas at Austin compare the amount of water used for petroleum refining vs. electricity generation. King and Webber found that electricity generation "consumed" or evaporated three times more water than gas production. During electricity generation. seventeen times more water is "withdrawn", used as coolant and returned to its source. "I wouldn't sound the alarm that this is going to ruin the day," says King, "But looking into the future, this is something we should take into account." King advises powerplants to switch to more expensive dry (forced air) cooling. Alternatively, "If we use only wind or solar energy, water use would be essentially zero." Where will we get the energy to build all those turbines and panels? Fossil fuels, of course.
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I guess they missed the point that water doesn’t ever really go away on the planet unless its shipped off the planet.
We learned that back in elementary school…you have to love the water cycle.
Dams, diversions and groundwater mining are not exactly nice though are they?
If the water is returned to the source without being polluted. And the source is large enough the heat added is not significant I don’t see the big deal. Also I suspect the forced air coolers are much less efficient thereby consuming more power. And on and on it goes. Plus what do Texans know about water??
As far as wind and solar I suggest they stop talking (fat chance) and start building. Texas should be covered with turbines and panels. Then we will really see how effective they are on a large scale.
Juniper:
Texas should be covered with turbines and panels. Then we will really see how effective they are on a large scale.
Actually, Texas now leads the nation in wind power facilities. They often give good service, but the intermittent nature of wind power poses challenges.
Regarding the main post:
Where will we get the energy to build all those turbines and panels? Fossil fuels, of course.
While we can indeed assume that the energy needed to product the materials that go into a renewables plant comes largely for fossil sources, we are left with the following question: So what?
The amount of power it takes to manufacture a turbine or solar array is a very small fraction of the amount it will eventually generate and feed back into the grid. You are spending a little fossil fuel now in order to avoid burning a whole lot more later. And you don’t need more cooling water later.
Over the long term, cooling water has not been a major issue for most power operators. The recent southern drought has been the exception to this, and raises legitimate questions about the planning that has gone into existing plants.
If the recent drought is in any way tied to global warming, and if that is tied to fossil fuel usage, then the irony becomes acute: We are encountering difficulties generating the electricity we need to get away from gasoline, because of all the gasoline we’ve previously burned (and now will be forced to continue to burn).
True, most electric power that we’d feed into electric vehicles comes from fossil fuel sources. But nuclear plants (no CO2) were also affected by the drought. In any event, most electrical generation and electric drive systems are more efficient than gasoline motors, so even if the electricity is eventually traced back to a powerplant smokestack, the CO2 per mile driven rate of emissions is generally lower.
I agree with Orian, pretty sure water is a renewable resource, what with all that evaporation and precipitation and whatnot.
But in any case I already subscribe to 100% Wind Power here in TEXAS — and not because I’m some pot-smoking hippie burnout but because it’s 25% cheaper than what I was previously being charged for fossil electricity from the former monopoly fatcat. That’s competition for you.
No offense to pot-smoking hippie burnouts.
@Juniper,
“Plus what do Texans know about water??”
More than you, hero. The center of Texas covers a HUGE aquifer that has more than likely fed the fields that have grown some of the food you have been eating all your life. Our agriculture folks, many educated at Texas A&M (a top school in Ag in spite of all the jokes we tell about them) have been managing and protecting it for a long time. This study was published from UT which like many other top universities (top 10 I believe) in the country is full of liberal bias, and experts on everything.
So we have a whole lot of people here who know a whole lot about water. If you thought all we know about here is oil and gas, you should get out more.
What we do lag in expertise here is how to get the government to pay for all our failures. Maybe we should hire some more lobbyists and consultants for that.
Where will we get the energy to build all those turbines and panels? Fossil fuels, of course.
Funny, but untrue.
Much of the silicon used in the production of solar cells comes from hydropower.
Also, the energy balance of solar and wind is strongly positive, i.e. they produce a lot more energy over their lifetime than is used for their production.