It seems that the United States might have a whole lot more natural gas than previously thought.
Normally, I’m not too excited about fossil fuels, as they seem to be a Big Part of the Problem.
But natural gas burns a lot cleaner than coal. These new deposits could help us to reduce our CO2 output right away.
But by how much?
Technology Review has a nice article in its December 2009 issue entitled: Natural Gas Changes the Energy Map (the link is for subscribers only, but try here for a “peek inside”)
The article states that new discoveries combined with advanced extraction techniques have resulted in estimates of natural gas capacity that are way higher than even just a few years ago. Some experts now believe the US may have enough gas resources to last up to 90 years at current consumption rates. Or, if gas were to totally replace coal in generating electricity, we might still be able to go for another 50 years.
I wanted to get a feel for just how much CO2 reduction could be realized by a complete replacement of coal by natural gas, regardless of all the issues and logistics surrounding this new opportunity.
TR has some nice pie charts that illustrate where our electricity comes from, and the relative amounts of CO2 that each source produces:
These clearly show that coal burns much dirtier than natural gas. But they only deal with the electricity generating sector. I was intrigued by the idea of quickly cleaning up electricity generation by switching to gas. But I wanted to know how cleaning up this one sector would affect the entire country’s greenhouse gas debt.
So I created a series of stack-graphs that I hope will offer another interesting perspective. As in the first pie chart above, let’s look at how much electricity the US generates, by source. It is easy to see that coal is responsible for about half of the US’ electricity, and natural gas about a fifth:
coal is generates about half of electricity generation in the United States
When you look at the greenhouse gases produced by these electricity-generating technologies, you see that coal is responsible for a monster share:
but is responsible for more than its share of greenhouse gases
What’s interesting about natural gas is that it produces about half the amount of CO2 as coal for the same unit of electricity production. So if we were to completely replace coal with natural gas, electricity generation would get a lot cleaner. Below, COAL gets split into half “NATURAL GAS” and half “LESS CO2″ (otherwise known as “CLEAN AIR”):
click to view larger image
Great! Electricity generation could get 40% cleaner by switching to natural gas. But that is just electricity generation. The US also has a lot of cars and cows, so how does this relate to the total output of the country?
Luckily, the Department of Energy contains an agency called the U.S. Energy Information Administration. The EIA is the statistical and analytical agency within the DOE. They have a nice web site full of statistical information, and I was able to find data for the year 2007 in this report: Emissions of Greenhouse Gases in the United States 2007. Since the TR article was using 2007 data, I figured I’d follow suit.
There I was able to find that the electricity sector produced 2,433 million metric tons carbon dioxide equivalent in 2007. Meanwhile, the total estimated greenhouse gas omissions for the USA in 2007 was 7,282 million metric tons.
Knowing these amounts, it is easy to compare that nice green bar of clean air we saw earlier with the total, to get an idea of the impact that natural gas could have:
click to view larger image
We can see that electricity generation produces around 1/3 of the USA’s greenhouse gases, and replacing coal with natural gas could reduce that total by around 13%.
Knowing this ballpark figure gives a good basis for better understanding the debate. The Technology Review article goes into the pros and cons of switching to gas.
Proponents believe that clean-burning natural gas would offer us a bridge to the future. We could get cleaner quickly and buy more time to invent new energy capturing technologies and develop renewable resources. Plus, we get cleaner without depending on foreign fuel sources.
Opponents warn that this could be a trap that sucks us into being addicted to yet another non-renewable fossil fuel. If the reserves turn out to have less than anticipated, then mass conversion of coal-fired plants to natural gas plants could leave us stuck having to import (and pay for!) natural gas from other countries.
It’s an interesting article, with interesting issues. If you decide to check it out, I hope my visualizations will add to your understanding of the debate.