A path for reducing CO2 pollution from coal is production of natural gas from hydraulic fracturing by drilling deep and then sideways and using steam and chemicals to cause fractures in shale deposits, which eventually release trapped natural gas. Since natural gas releases only about one half of the CO2 as coal does for the same power, switching from coal to natural gas could lessen our CO2 pollution by half of the 2,000 million metric tons (mmt) from coal or by 1,000 million metric tons out of 6,000 mmt total. This was strongly embraced by environmentalists about two years ago.
Then it was pointed out that someone’s tap water could be lit with a match, and the tide turned fast. It was never proved that it was from fracking. It is true that the fracking companies were not taking responsibility for purifying or disposing of the water and chemicals that they used, or revealing what chemicals that they used. This has to be covered by regulations, and they have to pay for disposing of the water and making sure that ground water is not contaminated, although they are fracking far below it. Since the public may be exposed to such chemicals, it is within the rights of the public to find out what the mixtures are and to regulate their disposal. It also can significantly lower the exposure risk if in comparing formulas we find those that are just as effective but use less amounts of or fewer dangerous chemicals. It is to the advantage of the fracking companies themselves to perhaps learn of better formulas. Win, win, win, win.
From a greenhouse gas viewpoint, natural gas or methane CH4 is 23 times as potent a greenhouse gas as CO2 is. So if only 4% of the methane escapes without being flared off or burned to CO2, when it replaces coal, it still has the same CO2 plus CH4 greenhouse effect as the CO2 from coal itself did. A recent measurement in Colorado inferred that the escape rate there without new regulations was 9%, meaning a 50% increase in warming over coal. With proper laws, regulations, and inspections we should be able to achieve zero emission natural gas production and use. It is way to early to give up on this hope. All of the processing of waste-water, limiting of sites, and zero emission safeguards, will of course raise the price closer to that of coal, which already is fairly well regulated. The oil and natural gas companies are vastly profitable and have vast resources to carry out secure natural gas production.
The US Environmental Protection Agency has just ruled that drilling companies have to flare off all emissions. Starting in 2015, they instead have to capture all methane emissions and volatile organic compounds for resale. They are also launching a study of such emissions. An MIT study says that methane from fracking is only 3.6% of methane from all natural gas production.
Another advantage of natural gas is that it can be placed near cities and embedded with industrial or residential campuses where it can also be used for hot water heating and air heating and conditioning, thus achieving very high efficiencies, far above the 33% efficiency of a stand alone fossil fuel plant. Con Edison in New York City claims an 85% efficiency.
The other side of the shale gas and tight oil optimism was just presented by J. David Hughes in Nature, Vol. 494, 307-8 (2013), in A reality check on the shale revolution. First, he points out that 40% of current natural gas production is from shale, and 61% of US wells are horizontal. Sensibly, the wells producing now are in the sweet spots, and future wells will be less productive. Also, the wells only produce plentifully for two to three years, which is the case with ordinary gas wells also. He also estimates that gas is priced low now due to overproduction and actually losing money. The estimate by the Energy Information Agency of shale gas lasting to 2040 is claimed to be far overestimated. Gas should not be exported under these circumstances.
This is one of those situations where if the federal government does not set standards, the gas producing companies will have to negotiate around 50 different state standards. Those states that are controlled by fossil fuel producers, would of course set lax standards, and green states might over-regulate more than needed, or put a ban on fracking. It is good that the EPA has set a standard on capturing gas.
While we wish that other countries would follow our lead, the likelihood of such safeguards being put into effect or rigorously enforced in failed states or those dominated by fossil fuel producers seems pretty slim.
