Environment Counts | IEA is projecting the golden age of natural gas, but what are the environmental implications ?
Author: Geoff Zeiss – Published At: 2011-07-19 09:51 – (1074 Reads)
According to the International Energy Organization’s Golden Age of Gas Report natural gas will play a greater role in the global energy mix, because of its relative abundance in the form of shale gas and because natural gas produces 50% less emissions than coal for the same amount of energy. But environmental issues may dampen the expansion of natural gas exploitation
It is estimated that the total available supply of natural gas in the US is about 2,000 trillion cubic feet, equivalent to about 100 years of supply at current rates of consumption. The impact of shale gas on the US economy is hard to underestimate. Recently FERC Commissioner Philip Moeller said that the biggest recent trend in the energy industry is the huge impact that shale gas has had on the energy industry by pushing gas prices down and keeping them there. The drop in gas prices has affected wholesale power markets and resulted in lower energy prices for consumers. But the price drop may not help developers of new renewables, nuclear, clean coal, or new gas pipelines. The question now is whether the benign regulatory environment can continue given the environmental impact (GHG emissions and water quality) of the shale gas industry that is now just coming to light.
In the US in 2009 there were 493,000 active natural-gas wells, around 90 percent of which are shale gas wells which use a process called fracking to increase gas production. Fracking is a process in which a hydraulic fracture is formed by pumping a fracturing fluid into the well at a high enough rate that the pressure causes the shale to crack. To keep the fracture open, a solid material, typically sand, is added to the fracture fluid. The result is a permeable conduit that allows natural gas and other fluids to flow to the well. The injected fluid mixture is approximately 99% water and sand but with additives that can include any of up to 600 chemicals. A typical frac will utilize approximately 15,000 cubic meters (4 million US gallons) of water per well and it is typical for a well to be fracked up to 18 times.
In 2005 Congress passed the Energy Policy Act of 2005, which was an omnibus energy bill (that among many other things changed daylight savings time in the US). Among the provisions of the bill was the so-called “Halliburton loophole” that exempted hydraulic fracturing from protections under the Clean Air Act, Clean Water Act, Safe Drinking Water Act, and CERCLA, which means that fracking is not regulated at the federal level. It has been argued that state regulation is not effective for a variety of reasons.
The New York Times collected data from more than 200 natural gas wells in Pennsylvania and was able to map 149 of the wells. It was found that drilling wastewater from these wells frequently exceeded federal drinking water standards for contaminants,
- 42 wells exceeded the federal drinking water standard for radium
- 4 wells exceeded the federal drinking water standard for uranium
- 128 wells exceeded the federal drinking water standard for alpha radiation
- 41 wells exceeded the federal drinking water standard for benzene
In 2009 and 2010, public sewage treatment plants directly upstream from drinking-water intake facilities accepted wastewater with radioactivity levels much higher than the drinking-water standard, but most of these sewage plants are not required to monitor for radioactive elements in the water they discharge.
A review of federal, state and company records relating to more than 200 gas wells in Pennsylvania, 40 in West Virginia and 20 public and private wastewater treatment plants found that
- More than 1.3 billion gallons of wastewater was produced by Pennsylvania gas wells over the past three years. Most of this was sent to treatment plants not equipped to remove toxic materials in drilling waste.
- At least 12 sewage treatment plants accepted drilling wastewater and discharged partially treated waste into surface waters.
Data from more than 65 intake plants downstream from some of the major drilling regions in Pennsylvania were reviewed. Not one had tested for radioactivity since 2008, and most had not tested since at least 2005.
A series of ProPublica reports has identified instances where ground water has been contaminated in drilling areas across the country and Gasland has shown examples of burning tap water and other effects attributed to fracking. The serious concerns about hydraulic fracturingâ€™s potential impact on drinking water, human health and the environment is serious enough that Congress has appropriated funding for the EPA to undertake a major study of hydraulic fracturing and its impact on drinking water. In Canada the Quebec government has halted shale gas driling because of leaks that the Quebec Ministry of Natural Resources said it had found in 19 of 31 shale gas wells it inspected.
In June of last year the South African exploration regulator Petroleum Agency SA issued shale gas permits to several oil and gas companies in the central Karoo. Shell, one of the companies granted exploration permits, is considering using fracking to increase natural gas production. Fracking uses a lot of water, averaging four million gallons each time a well is fracked. The Karoo is semi-arid and an environmentally sensitive area and there is concern in South Africa about the impact of shale gas exploitation on both water and air quality, partially motivated by the EPA investigation into the environmental impact of shale gas and fracking in the US.
It has been asserted that natural gas power plants, which are responsible for 21% of power generation in the US, produce 50% less emissions than coal-fired plants. However, in the past the amount of methane gas that leaks from pipes and is vented from gas wells has not been included in the calculation. Now a new EPA analysis doubles its previous estimates for the amount of methane gas that leaks from pipes and is vented from gas wells, which significantly changes the emissions picture. Methane (CH4) levels from hydraulic fracturing of shale gas were found to be 9,000 times higher than previously reported. Based on the new numbers, the median gas-powered plant in the United States is estimated to be 40 % cleaner than coal-fired plants, according to calculations ProPublica has made. In addition about half of the 1,600 gas-fired power plants in the US operate relatively inefficiently. In the past these plants were estimated to be 32 % cleaner than coal, but now with the new EPA estimates, these ~800 inefficient plants are estimated to produce 25 percent less emissions than coal.
But there is another issue. Methane is one of the more potent greenhouse gases for global warming, but it is not clear just how much more potent methane is than CO2. The EPA has estimated a factor of 21 times compared to carbon dioxide. But Robert Howarth, an environmental biology professor at Cornell University, has suggested that it is actually 72 times as powerful as carbon dioxide in terms of its warming potential. This is critical, because if the climate effect of methane from natural gas is 72 rather than 21 times that of carbon dioxide from burning coal, natural gas may even turn out to be worse than coal in terms of global warming. Recently Howarth said that the type of shale gas drilling taking place in Texas, New York and Pennsylvania generates particularly high emissions of methane and could be as dirty as coal.
A new study by Robert W. Howarth, Renee Santoro, and Anthony Ingraffea has concluded that the emissions of methane from shale gas wells are between 30% and 100% more than methane emissions from conventional natural gas wells. The study estimates that between 3.6% to 7.9% of the methane from shale-gas production escapes to the atmosphere in venting and leaks over the lifetime of a well.
As a result the study found that the greenhouse gas (GHG) footprint for shale gas is greater than that for conventional gas or oil. When compared to coal, which is responsible for nearly 50% of electric power generation in the US, the GHG footprint of shale gas is estimated to be 20% to 100% greater than coal over a 20 year period. Over a 100 years, the study concludes that the GHG impact of shale gas is comparable to coal.
IEA Golden Age of Gas Report