Water Shortages to Hit Green Energy, Shale

Intensive use overlooked?

Ken Silverstein | Aug 21, 2011

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Leaders are pondering the nation's energy fate without adequately considering the effect that such policies will have on limited water supplies. Energy production is water-intensive -- a fact that could likely impede green energy development as well as that of shale gas.

Those are the findings of the World Policy Institute that emphasizes to political leaders that they must consider the nexus between energy policy and water consumption. Indeed, the technologies to reduce carbon emissions are coming to the fore. But some of those ideas require high levels of water -- a scarce resource that is required by all energy forms.

In this country, droughts have decreased the pool of water now available to all concerns. Not only do utilities use it. So does big industry and small residential households. To compound the matter, the demand for electricity here is expected to rise by 1.5 percent a year over 20 years. Governments and businesses alike are now calling for concerted conservation efforts. Another approach being pushed is the development of new utility technologies that require less water.

In Texas, the combination of hot summers and water shortages are pitting farmers against shale-gas developers. Diana Glassman, who co-authored the report for the think tank, says 13 million gallons of water are required in the southern portion of the state. The idea that shale-gas will become the next gold rush is therefore jeopardized, particularly because its production requires seven times the amount of water as does the extraction of conventional natural gas.

"The competition between water and energy needs represents a critical business, security, and environmental issue, but it has not yet received the attention that it deserves," says Glassman. "Energy production consumes significant amounts of water, and vice versa. In a world where water scarcity is a major and growing challenge, water deserves a place on the energy agenda alongside cost, carbon and security considerations."

According to the World Policy Institute, coal-and-oil-fired power plants consume roughly twice the water than that of gas-fired facilities while nuclear generation needs three times that of natural gas. Cleaner coal technologies such as coal gasification will reduce that need by as much as half but, emerging concepts like carbon capture and burial could increase consumption between 30-100 percent.

Wind and rooftop solar panels, meantime, are the most efficient forms of generation when it comes to water. However, large and commercial solar plants use twice the water as coal and five times the amount as gas-fired plants. Further, corn-based bio-fuels used in transportation consume much greater amounts of water than does the drilling for traditional oil.

The National Energy Technology Laboratory adds that the average thermoelectric plant uses 25 gallons of water to produce one kilowatt-hour of power using current technologies. If a household uses 1,000 kilowatt-hours a month, then 25,000 gallons of water must be withdrawn to provide that power from a coal-fired power plant.

The number jumps to 31,000 gallons a month if nuclear power is used to generate that electricity. Natural gas plants, however, use much less water. By comparison, a typical household might consume 10,000 gallons of water a month.

Most power plants today use "once-through colling" in which nearly all the water is returned to the source. Less than 1 percent is lost through evaporation or leaks in the system, says the U.S. Department of Energy. Newer technologies use "closed loop" systems that rely on "cooling towers" and "re-circulate" the water.

Access to fresh water supplies is a universal issue extending well beyond the United States. But developing nations are having the toughest time. The problems are exacerbated because of the fears of climate change. The United Nations Foundation's Global Water Challenge says that about a third of all countries now have water scarcity issues and that this level could rise to two-thirds in 20 years because of global warming.

"Water is the new oil," says Jim Rogers, chief executive of Duke Energy, in a talk with this writer. When utilities formulate their energy portfolios, they must take water availability into consideration.

Any exacerbation of the current water shortages will weigh heavily on all concerns and particularly on utilities that require large quantities of water to produce electricity. Newer technologies will eventually alleviate some of the pressures. But the whole issue underscores why energy efficiency must become a focal point of American public policy.

The editorial staff at RenewablesBiz.com is passionate about exchanging ideas and dedicated to promoting ongoing conversation about renewables and sustainable energy issues. We invite you to join and contribute to our online community. If you have an idea for an article or editorial contribution, please contact me via email, bopalka@energycentral.com, or phone, 860.633.0090.

Comments

Critical Comments are Indicative

I don't know whether it's the pressure to write a daily article or the desire to promote green-centric philosophies in the face of troublesome data....or something else altogether....but many (if not most) of the articles posted here are laughably thin on meaningful detail. It is rather common in modern journalism to use broad generalities as a means do dumb-down complex issues. Unfortunately, one mans "broad generality" is another mans bald face lie...particularly when your readership largely consists of people with significant engineering experience.

Power Water Use

Ken,

I have to disagree with your basic premise since it is based on historical use that is changing today. Steam power plants do not need to use large quantities of water. The current generation of plants was designed when water was cheap and, therefore, used a lot of water to minimize cost and maximize efficiency. The technologies are available today to reduce water consumption to almost zero. However, application of these technologies increases capital cost and reduces efficiency.

I am familiar with several plants that utilize air cooling and need water for only cycle makeup, generally less than 50 GPM. Some of these plants use municipal wastewater for makeup and recycle their own wastewater, resulting in zero discharge of water. This technology is aplicable to any steam plant, regardless of fuel.

In many parts of the U.S. there have been water use isses for years and power plants are in operation that have successfully adressed these issues. The technologies are well developed and commercialy available. Thus, I believe that power plant water use is really a non-issue.

Dave

Water needs analysis

I concur that this article needs editing. The DOE Publication "Estimating Freshwater Needs to Meet Future Thermoelectric Generation Requirements" provides firm data for appraising the issue. It reveals, for instance, that only about half a gallon of water is actually consumed in generating a kilowatt-hour of electricity. The 25 gallons identified by Ken refers to temporary withdrawal, not final usage. The fact that the World Policy Institute is analyzing this problem could hypothetically reflect an ongoing neglect of considerations paid by local plant licensing authorities in assessing water needs. I would be wary of harboring such a suspicion, however. When a chief power company executive states that "Water is the new oil", he may simply be preparing his customers for a rate hike. Yet his next statement makes one wonder what his professional qualifications are to begin with: "When utilities formulate their energy portfolios, they must take water availability into consideration." That's first semester power engineering. It would be interesting to determine under such circumstances who has financed that WPI study.

Water & Energy

Ken, Water is a very tough issue and glad to see you tackle it. You article, however, seems to raise more questions than answers.

- I think your statement that "most plants use one-through cooling" is inaccurate, although most could be just 51%. What is the problem with once-through cooling if the only impact is to heat up the river/resevoir? 

- By your measurement, isn't it accurate that wind and PV solar use zero water?

- Is the fundamental question actually conservation of our freshwater supplies? If so, where are our freshwater suppliers "contaminated"(?) today? My understanding is that 48% goes to agriculture, 49% to energy, and about 3% to households?

Please do more work on the nexus of water and energy - agree that much more education is needed.

re: Water Shortages

While this is an issue, making quotes like "...13 million gallons of water are required in the southern portion of the state." This was for Texas which is enormous. Southern portion means what? 13M gals per day, per year or how often?

The article then goes on to correct the initial alarm sounding that various technologies use (too) much water per kWH with the once through and closed loop parts.

Even on Solar it sounds like PV is OK then immediately goes to "solar plants" presumably CSP ones but does not so state.

This article needs some serious editing.