On Carbon Joe

(Posted by John)

Getting back to energy issues.

Our little parable was not just an exercise in bad writing. Rather, I hope to use it as a way of organizing my thoughts on energy and the problems we face in the 21st century.

The first coffee shop we looked at was Carbon Joe's, and with good reason. Fossil-fuel sources of energy (Coal, Oil, and Natural Gas) made up 2/3 of the world's energy consumption in 2002, according to the International Energy Agency. It isn't a stretch to say that, if you live in a western economy, you shop at Carbon Joe's. However, these resources are all used for very different purposes. Energy, as you'll remember from high school, is simply the ability to do work. The three forms of fossil fuel all do very different forms of work. While I've grouped them all in to one family, this is a writer's trick and not an accurate presentation. Coal, Oil, and Natural Gas - while all made up of long-dead plants and animals - are very different in their composition and uses.

Coal is one of our largest and oldest sources of fossil-fuel energy. It currently generates 39% of the Earth's electricity, makes up more than half of US generation, and 75% of China's. Moreover, unlike the situation with our other sources of fossil fuels, coal is relatively abundant - a century or more at current usages. However, the drawbacks of coal are well known. It's very dirty, as fuel sources go, it's very inefficient, and it makes more CO2 for every watt generated than any other source of energy. In the US, old coal generators aren't covered by the Clean Air Act, and are thus capable of being as polluting as they like.

There's been some talk lately of new "Clean Coal" technologies that would magically make the US energy independent without further hurting the environment. While many of these technologies are much, much better than old coal generators, there is literally no way to prevent coal combustion from producing CO2 in large quantities. The best that could theoretically happen is finding a way to bury ("sequester") the CO2 underground, but this is a) difficult and b) likely to be more expensive than utilities would want to pay for without government twisting their arms.

Natural gas is a much cleaner, and efficient form of energy than coal. It's also been cheaper to use for the last few decades, though this is changing. Because of it's virtues, natural gas now makes up more than double the total energy consumption of coal. This contrasts with the situation thirty years ago, when coal and natural gas were roughly equal. (Note that this is energy, not electricity. Natural gas provides just a bit more than one third of coal's electricity production.) Natural gas is familiar to about 1/3 of the homes in the US, where it provides heating and cooking fuel. It has also become a useful fuel for electricity generation in recent decades, both because of it's efficiency and the small sizes NG plants can be built. Their modest sizes and agility makes NG plants perfect for producing electricity during peak hours.

Of course, natural gas is still a fossil fuel, which means it releases CO2 in smaller amounts when it's burned. Furthermore, Methane is an extremely potent greenhouse gas in and of itself, so much so that if even 5% of consumed natural gas escapes without being burned, the effect is actual worse for the climate. Since the dawn of the industrial age, the concentration of methane in the atmosphere has about doubled. On the plus side, methane does seem to have a shorter lifespan in the atmosphere (it reacts with oxygen, unlike CO2) so if we stopped emitting methane it would return to pre-industrial levels in a few decades.

Finally, there's the big papa - oil. For total energy use, oil is the 800-lb gorilla. Oil alone makes up 43% of world total energy consumption. Overwhelmingly, oil is used for transportation fuel - 60% of oil's end use is simply moving stuff around. These are global numbers - in the US, that figure is 70%. In some countries (primarily oil exporters) oil is used to generate electricity, but this largely came to an end in the west with the oil shocks of the 1970s. In the US today, less than 1% of electricity is generated from oil. Oil combustion is a cleaner form of energy than coal, but dirtier than natural gas.

Oil's real virtue comes from it's ease of use. Within a few years of it's first discovery in the US, many of the early techniques for refining oil had already been developed. It's high energy content and ability to be stored easily as a liquid make oil a very appealing fuel. Interestingly, gasoline was largely ignored as a motor fuel early on in favour of diesel, steam, and electricity. However, the Model T changed all that. By the 1930s gasoline was the dominant motor fuel in America. Today, diesel cars make up a small fraction of the US light-duty fleet (cars, minivans and SUVs.) This number is higher elsewhere in the world, where fuel prices are higher. Diesel is dominant in US trucking and heavy vehicles.

There is literally no substitute on the market which combines the energy content of oil with the ease of use. Natural gas is comparable in energy, but is harder to store and move. Electricity is easier to move, but harder to store (and so far impossible to store in comparable energy.) Coal is both harder to move and store, is dirtier, and doesn't hold nearly as much energy.

It's important to have a grasp of these facts before we move on to questions of resource depletion. As we'll see, none of these resources is guaranteed to last as long as we might think. For reasons that I'll get in to in the next post in this series, we will need to replace the energy we get from these fuels, and sooner than we think.