Environmental Engineering Reference
In-Depth Information
is not often worth it. But in the future, it might be worth it—which means that claims that we'll “run out
of oil” are misguided, as coal and gas can effectively produce oil if needed.
For example, coal can be transformed into liquid fuel; the South African energy company SASOL says
it can be done for less than eighty dollars per barrel.
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Coal can also be transformed into methanol—methyl
alcohol, an alcohol that like ethanol can come from plants but can also come from coal and gas. Methanol,
like any fuel, has its own risks and by-products, and it has only half the energy per gallon as gasoline, but
it is still a potential substitute for oil fuel as markets evolve.
Coal use is growing quickly and could grow even more quickly. The United States could be a major
contributor; we have been called the Saudi Arabia of coal and have the potential to become a huge coal
exporter, feeding cheap energy to machines around the world.
The bottom line: If people are free to use it and the industry is free to produce it, coal energy will
provide billions with cheap, plentiful, reliable energy for decades to come.
NATURAL GAS
Natural gas is the world leader at an essential type of electricity—called
peak load
electricity.
Just as your energy use varies during the course of a day, so the electric grid as a whole uses different
amounts of electricity at various times during the day. There is a minimum amount of electricity use that
will almost always be needed, called base-load power. Above that, we need a technology that can quickly
adjust to changes in electricity needs—such as powering a lot of air conditioners on a hot summer day so
that we can be comfortable and avoid heatstroke. This is called peak load electricity, and it is natural gas's
specialty. (Coal, nuclear, and hydro specialize in base-load power.) Natural gas electricity, which uses the
same basic technology as a jet engine, is very good at scaling up and down.
Natural gas is also an extremely clean-burning fuel, composed almost exclusively of pure carbon and
hydrogen, which makes it ideal to burn for affordable home heating. In addition, it serves as an affordable,
abundant raw material for thousands of “petroleum products”—which we will discuss in the next section.
The disadvantage of natural gas is in its name—it's naturally a gas. Gases are harder to move long dis-
tances than liquids or solids due to their large volume. So while oil and coal can be moved relatively easily
around the world, gas has long been a local market. This causes supply security issues in which one coun-
try is dependent on an unreliable country for gas supplies—the case with many European countries that
depend on gas from Russia.
However, new technological developments are overcoming these obstacles.
One is shale energy technology, often referred to as fracking in the media and fracing in the industry.
Fracking is short for hydraulic fracturing, one of several technologies that can be used to get natural gas
out of shale. This technology has attracted attention based on claims that it contaminates groundwater. As
we'll discuss more in chapter 7, the controversy here, as with nuclear, is more ideological than technical.
The shale energy revolution has led to a rapid increase in natural gas and oil production in the last dec-
ade and has the potential to do much more.
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The combination of horizontal drilling and fracking has turned
previously known but economically unreachable reserves of natural gas into easily accessible and cheap
natural gas. In the United States, proven reserves of natural gas have increased 46 percent since 2005.
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