Full-page ads running in major newspapers promise: “Clean, domestic and abundant energy. Ready right now.” This vast and ready new energy source turns out to be an old friend – natural gas. In fact, the news about natural gas is very positive. But the solution to all our energy problems? Not quite.
The good news is that the recoverable U.S. natural gas resource jumped by more than a third just in the last few years, thus extending the potential life of domestic gas supply by more than 25 years at the current consumption rate. Essentially all of this increase is due to something called shale gas. Geologists have known about shale gas for some time, but it has been trapped so tightly in its geologic formation that normal gas well drilling technology could bring very little of it to the surface. New drilling technology extracts much more, thus leading to the increase in the resource estimate.
So what should we make of this windfall?
First of all, having an abundant domestic gas supply is a very good thing. Natural gas supplied 43 percent of residential energy use in 2009, and more than 35 percent of the energy for commercial buildings. It also accounted for 23 percent of electricity generation and plays a major role in industrial processes, especially in the chemical industry. It’s reassuring that a larger homegrown supply of natural gas should be around to support these essential markets.
Moreover, natural gas is likely to have a critical role in moving the electric power industry away from coal. Natural gas power plants are excellent backups to variable energy sources like wind power, and so may be essential to the growth of renewable energy. Even more advantageous is that natural gas contains about half as much carbon as coal. For this reason, producing electricity from natural gas could be an important bridge to a time when carbon dioxide emissions from power plants are no longer tolerated.
But natural gas can’t do everything. For example, while it’s possible to burn natural gas in existing internal combustion engines, hauling it around in the family car requires a large compression tank that’s both clumsy and expensive. Long-haul trucks, on the other hand, could run on liquefied natural gas, and according to a recent study from Resources for the Future, that could cut domestic oil consumption by almost 10 percent per day by 2030. That’s significant, and potentially worth the expense of building trucks that could use natural gas. Nevertheless, even abundant domestic natural gas supplies can make only a modest contribution to solving our addiction to oil.
Another reason to temper enthusiasm is that sustaining significant production from shale gas is tough. One challenge is that the production from each shale gas well drops off quickly and sharply — in some fields, on the order of 70 percent in the first year. The reason is that gas doesn’t flow easily through the very tightly grained shale formation, so almost all the production comes from gas nearest the borehole. To maintain production therefore requires repeated new drilling, with the result that sustained production from shale gas requires a continuous industrial enterprise.
This more or less permanent drilling program creates a second challenge, which is managing the environmental risks inherent in accessing tight formations like shale. Producing shale gas requires drilling a well horizontally along the formation (rather than vertically through it), and then fracturing the surrounding rock with water under enormous pressure. The water also contains a cocktail of additives that help increase production, some of which may be toxic. All of this adds up to a big job of acquiring — and then safely disposing of — very large amounts of water more or less continuously over the life of the gas reserve without depleting or contaminating the local water supply. Not everyone is comfortable with these risks. New York, where part of the large Marcellus shale reserve lies, seems ready to suspend shale gas production until the environmental issues are more clearly understood.
On balance, though, natural gas has a bright future in the United States. It’s not the answer to all of our energy problems, but it’s certainly a valuable asset over at least the next couple of decades. It’s not quite as ready now as the ads would have us believe, but the technical, environmental and even cultural obstacles should yield to thoughtful and disciplined management. Better to concentrate on that than on full-page ads.
Robert Fri is a visiting scholar at Resources for the Future, a nonprofit organization that studies natural resource and environmental issues. He has served as director of the National Museum of Natural History, president of Resources for the Future, and deputy administrator of both the Environmental Protection Agency and the Energy Research and Development Administration. Read his full bio.