Wednesday, February 9, 2011

Natural Gas is Less Climate-Friendly Than We Thought. So What?

This isn't the newest news, but back in late January, investigative journalists at ProPublica revealed that natural gas may release more carbon then we thought into the atmosphere. The mechanics and measurement of carbon released by a given energy source are very much up for debate, and according to the latest method from the EPA, natural gas may be a lot dirtier than we think it is.

Here's a nice, big block quote from the meat of the article:
The EPA’s new analysis doubles its previous estimates for the amount of methane gas that leaks from loose pipe fittings and is vented from gas wells, drastically changing the picture of the nation’s emissions that the agency painted as recently as April. Calculations for some gas-field emissions jumped by several hundred percent. Methane levels from the hydraulic fracturing of shale gas were 9,000 times higher than previously reported.
When all these emissions are counted, gas may be as little as 25 percent cleaner than coal, or perhaps even less.
Even accounting for the new analysis, natural gas—which also emits less toxic and particulate pollution—offers a significant environmental advantage. But the narrower the margins get, the weaker the political arguments become and the more power utilities flinch at investing billions to switch to a fuel that may someday lose the government’s long-term support.
 The thing here is that it's not just the burning of the a given fuel that causes carbon emissions. A lot of analyses of the nuclear industry in particular look at the total life cycle of the fuel--carbon and other greenhouse gases that are expended in the processes of mining it, transporting it to refinement plants, refining it, trucking it to power plants--which the EPA also takes into account. The news here is that some of those ancillary emissions are higher then we thought, and that can damage gas's reputation as the clean fossil fuel.

Natural gas rig
Part of story for ProPublica is that the new measurements could hinder the way politicians view the gas, and we can extrapolate that to the role gas will have in President Obama's new energy policy. However, from my point of view, this isn't as big of a deal as it sounds like.

The thing about this story is the larger background: the fact that U.S. electricity usage is projected to increase around 30% in the next twenty years (as I found in the background knowledge for my nuclear research project). That's a huge gap, and something has to fill it. We have proposals that could squeeze more electricity out of the system we've got now; the idea for a smart grid, which is gaining traction, would make our power grid more efficient and make it easier for individual houses to generate electricity themselves, for themselves. And improving our power lines so that we lose less electricity in transit could cover more of that demand, but it won't cover all of it.

We'll need more large power plants to generate electricity at a centralized location and transmit it to different communities, without any doubt. And the thing about power generation on a large scale is that there's no perfect source. Every method has its drawbacks. Gas has the aforementioned emissions concerns, as well as the potential dangers of "fracking", or hydraulic fracturing of shale rock to draw out gas. Coal is just dirty,  'clean coal' remains uncertain and old oil-fired power plants are even worse. Nuclear plants generate waste and are expensive to build (more so than these other). Solar and wind are both unreliable by definition, and each have their own carbon concerns. Geothermal power is difficult to get to, and hydropower is only usable in very specific places (mostly the Pacific Northwest in this country).

The point is, there's no free lunch in power generation. Every source of electric power has its own drawbacks. Short of cold fusion, we are not going to find a power source that is able to meet the U.S.'s, or the world's, energy needs without these drawbacks. So even though natural gas produces more emissions then previously thought (and a lot of the waste and emissions described in ProPublica come from our infrastructure, not a property of the gas itself), that's not a reason to automatically discount it. It's still cleaner then coal, there are still massive reserves of it in this country, and it's still a major part of the U.S.'s energy future. Keep that in mind when reading articles like ProPublica's. (At the same time, don't discount information like this, which we will have to account for when the government hands out subsidies for new plants.

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