Water protection council comparison shows nuclear, conventional oil next in line
BY KAY CASHMAN FOR GREENING OF OIL
In a country craving domestic sources of clean energy one would think Americans would welcome abundant supplies of newly discovered natural gas from shale. For the most part they do.
But the process of extracting natural gas from shale has prompted concerns from the people living in areas where this unconventional gas production is planned, or already happening.
One of their concerns is the large amount of fresh water required by shale production; water that is largely lost from fresh water supplies.
Greening of Oil decided to follow this issue, primarily by keeping on top of what shale gas producers were doing to develop technology that would allow them to reuse water versus disposing of it deep beneath the water table. (See article posted in Tracking fossil fuels section on Jan. 9, titled “Pilot test aims to recycle water in shale production.”)
In the course of that investigation, we discovered that natural gas development from shale uses the least amount of water for the energy it produces, followed by nuclear and conventional oil. At the other end of the list, requiring thousands of gallons more water per unit of energy, is ethanol from corn and biodiesel from soy.
Laying out the facts
Going back to the beginning of our research into the subject of water use and shale production here is what we learned, in more or less chronological order.
Due to hydraulic fracturing , a technique that releases natural gas from shale rock deep in the ground, estimated gas reserves in the United States surged by 35 percent between 2006 and 2008, per a mid-2009 report issued by the Potential Gas Committee.
The increase to 1,836 trillion cubic feet was the largest in the 44-year history of the committee, which consists of academics and industry experts and is supported by the Colorado School of Mines.
Recent multibillion dollar deals by ExxonMobil and Total suggest industry mega-majors other than BP are betting that the boost in gas reserves will continue into the future.
The announcement of a 35 percent increase in natural gas reserves in a two-year period created speculation that natural gas could be a key power source in the transition to a more earth friendly energy future; something that came as no surprise to a few companies long invested in shale, such as Chesapeake Energy, Devon Energy, XTO Energy and Anadarko Petroleum, because natural gas is cleaner than coal, cheaper than oil and the United States has at least a 90-year supply.
And that does not count natural gas hydrates, which were not included in the committee’s estimate. North America potentially holds another 64,000 years of energy from natural gas hydrates—if, some say, industry and government make a serious commitment to developing the technology that will make hydrate production commercial. (See Petroleum News 2008 article link at the end of this article and watch for an upcoming article in Greening of Oil.)
Clean, low cost, abundant—and revolutionary?
Following the Potential Gas Committee’s reserve announcement Daniel Yergin, a Pulitzer Prize winning author and chairman of IHS CERA, an energy consultancy, asked if Americans would now look at natural gas as a much longer-term power source, and not simply a bridge to a future of alternative fuels.
“The question now is how does this change the energy discussion in the U.S. and by how much? This is domestic energy. ... It’s low carbon, it’s low cost and it’s abundant. When you add it up, it’s revolutionary,” said Yergin.
Moreover, Greening of Oil discovered the conventional natural gas industry had been reducing its methane emissions for several years.
According to the U.S. Environmental Protection Agency, methane emissions in the United States dropped by 5 percent from 1990 to 2007—during the same period methane emissions from natural gas declined 25 percent due to advances in technology and the industry’s investment in equipment upgrades. Most of these efforts were voluntary and not mandated by government regulation, but driven in part by expectations from the general public, by company commitment to environmental stewardship, and by the profit mandate inherent in all for-profit entities. (Making more money is often directly tied to reducing a company’s environmental footprint because it generally involves capturing more of a power resource while using less land, steel and other things needed to produce the resource.)
Need water for both drilling and fracturing
Producing natural gas from shale requires water to both drill the well and hydraulically fracture the rock, which is deep underground. The water used for drilling and fracturing has to be recovered from the well and disposed of before gas can flow.
Although water requirements for shale are generally in the 1-1.5 percent range compared to water use by agriculture, industrial users and communities, concerns about the impact of shale drilling on water supplies and quality begged other questions: How much water is being used for energy production? And how does water use for natural gas from deep shale compare with other energy sources?
Who uses water in the United States?
But first, we looked at who uses freshwater in the United States.
According to Howard Perlman of the Interior Department’s U.S. Geological Survey, USGS compiles national water use reports every 5 years, but it usually takes 3-4 years to finalize and publish them, so the most recent data, from 2005, was released in 2009.
Saline water was not included in the following USGS numbers that Greening of Oil chose to review because Perlman said almost all (just under 95 percent) of saline water use is for thermoelectric power, essentially to cool hot equipment.
Generally, he said, saline water was taken “from the oceans and … would not have been of use to people anyway.”
In 2005, USGS said, 349,000 million gallons of freshwater was used in the United States by the following consumers:
Thermoelectric power: 41 percent
Irrigation (agriculture): 37 percent
Public supply: 13 percent
Industrial: 5 percent
Aquaculture: 2.51 percent
Domestic (self-supplied): 1 percent
Livestock (agriculture): less than 1 percent
Mining: less than1 percent
Mineral, oil and gas extraction combined
According to the USGS report mining use included water for extracting solid minerals such as copper; liquids such as petroleum; and gases such as natural gas.
Perlman said in an e-mail to Greening of Oil that the generation of thermoelectric power “uses huge amounts of water, most is ‘once through’ to cool equipment. In other words, most is taken out of a river/water source, used for cooling, and then put back into the river downstream (maybe hotter). Not a lot is evaporated or used up. …Thus, even though huge amounts of water go to thermo uses, almost all is put back into the ‘system,’ where it is available for use again.”
When water was used for irrigation of, say corn and soy, much of the water “ends up evaporating, getting into the foods, or going back underground, so consumptive use is high” because the water was not immediately available again for use.
Water use comparisons between energy sources
Onto the next question: How does water use for natural gas from deep shale compare with other energy uses?
The Ground Water Protection Council and the U.S. Department of Energy put together water use comparisons between energy resources and, surprisingly, natural gas development from deep shale used the least amount of water for the energy it produced.
The energy source that required the most amount of water was, unsurprisingly, plant-based biodiesel from soy, requiring a smacking 14,000 to 75,000 gallons of water per MMBtu of energy produced as compared to deep shale natural gas, which needed only 0.60 to 5.80 gallons, 2 gallons of which were estimated for transport of the natural gas.
One MMBtu, or 1 million British thermal units, a standard measurement for the energy content of fuels, was produced from these energy sources using the following amounts of water:
Deep shale natural gas 0.60-5.80 gallons
Nuclear (uranium ready to use in a power plant) 8-14 gallons
Conventional oil 8-20 gallons
Synfuel-coal gasification 11-26 gallons
Coal (ready to use in a power plant) 13-32 gallons
Oil shale 22-56 gallons
Tar sands/oil sands 27-68 gallons
Fuel ethanol from corn 2,510-29,100 gallons
Biodiesel from soy 14,000-75,000 gallons
Water facts from the U.S. government
Although deep shale gas operations produce comparably clean energy and use less water than all the energy sources noted above, the media coverage from this and other water-related issues and shale gas have Americans taking a closer look at water use, supplies and quality.
And that might not be a bad thing, based on other information Greening of Oil picked up during its research.
Here are some interesting water facts from the U.S. government:
· More than 90 percent of the world’s supply of fresh water is located in Antarctica.
· If the entire world’s water were to fit into a gallon jug, the fresh water available for us to use would equal only about 1 tablespoon.
· The overall amount of water on our planet has remained the same for 2 billion years.
· The United States consumes water at twice the rate of other industrialized nations.
· 1.2 billion people worldwide do not have access to clean water.
· Americans flush 6.8 billion gallons of water down their toilets every day.
· Each day almost 10,000 children under the age of 5 in Third World countries die as a result of illnesses contracted by use of impure water.
· Most of the world’s people must walk at least 3 hours to fetch water.
· On a global average, most freshwater withdrawls—69 percent—are used for agriculture, while industry accounts for 23 percent and municipal use (drinking water, bathing and cleaning, and watering plants and grass) 8 percent.
· It takes about 6 gallons of water to grow a single serving of lettuce. More than 2,600 gallons is required to produce a single serving of steak.
· It takes almost 49 gallons of water to produce just one 8-ounce glass of milk. That includes water consumed by the cow and used to grow the food she eats, plus water used to process the milk.
· About 6,800 gallons of water are required to grow a day’s food for a family of four.
· One fifth of the world’s freshwater fish—2,000 of 10,000 species identified—are endangered, vulnerable, or extinct. In North America, the continent most studied, 67 percent of all mussels, 51 percent of crayfish, 40 percent of amphibians, 37 percent of fish and 75 percent of freshwater mollusks are rare, imperiled or already gone.
· At least 123 freshwater species became extinct during the 20th century. These include 79 invertebrates, 40 fishes and four amphibians. (There may well have been other species that were never identified.)
· Freshwater animals are disappearing five times faster than land animals.
Links of interest
The University of Illinois Extension Service, among other credible sources, contends there are “common misperceptions” about water use for ethanol production, and makes a case on its Web site for significantly less actual water going into the production of corn ethanol.
USGS: water use in the United States
USDA: Irrigation and water use
River and water trivia
Water use calculator
Petroleum News: Tapping whole new fuel source; Canadian Arctic research team achieves first sustained flow of gas from Mackenzie Delta hydrates
Editor’s note: The official definition of thermoelectric-power water use from the USGS National Circular for 2005 is: “Water used in the process of generating electricity with steam-driven turbine generators. Term used in previous water-use Circulars to describe the combined public-supply deliveries to thermoelectric-power plants and self-supplied thermoelectric-power withdrawals. For 2000 and 2005, thermoelectric-power water use refers only to self-supplied thermoelectric-power withdrawals.”
Contact Kay Cashman at firstname.lastname@example.org
The following are comments from our readers. They do not represent the view of Greening of Oil or its owner.