|But most people have no idea where their electricity comes from or how it is made. We used to joke about people who thought that milk came from bottles, not cows. Well, electricity is like that today. Here is a story that makes the point:|
|How important is coal in generating electricity?
Very important. More than half of the electricity in the country is generated using coal. (See the Power Generation Chart below.)
|Meet your old friend coal.
Ask somebody "How much coal do you burn?" You're likely to get an answer like this. "A silly question" they will say. "We don't burn coal in our house! People used to burn coal, but they don't anymore."Then you say "Well yes, that's true, but only because somebody burns it for you -- the electric company. Got lights? A fridge? Hot water, a washer, air conditioning? Telephone, TV, VCR, maybe even a computer?" Most likely they'll say "Of course, almost everybody has that stuff."
Now you have them. Just tell them:
|Here's why. Almost all electricity is made by spinning a magnet,
called a generator. Most generators are powered by high pressure
steam blowing through a sort of fan, called a turbine. Coal has
always been our primary source of the steam used to make electricity,
for several reasons. First and foremost, coal is abundant. It
is found all over the country and it is easy to get to. In many
places it can be mined right from the surface. In other places
the miners go underground to get it. Because coal is abundant
and easy to get to, it is very cheap. It is also easy to transport
and store, compared to other fuels.
If you look at the Power Generation Chart you can see how we have made our electricity over the last 25 years. Oil and gas also have been burned to make steam, especially gas. They compete with coal primarily in places where coal is not found locally where they become competitive. But in most places oil and gas are more expensive than coal, especially oil. New gas-burning steam power plants are being built today. In addition oil and gas are burned in internal combustion engines to drive electric generators.
Since the 1970s, nuclear energy has become an important source of steam to make electricity, and it is now our second largest source of power. However, nuclear power has become very expensive because of concerns over its safety, so no new plants are being built. Water power can also turn a turbine, without steam, and hydroelectric power plants have always been important. However, they can only be built in special places, and some people object to the dams they require, so no new hydro plants are being built.
We also use a tiny bit of solar power, wind power, geothermal power, and some other stuff. But not enough so far to even show up on the chart.
So it is mostly coal and gas that we depend on for new generating capacity.
|"Well it all runs on coal, or mostly coal. Same for the stores,
the malls, office buildings and factories -- they all run on electricity,
which means they run on coal. True, we also use nuclear power,
some gas and oil, even some good old-fashioned water power to
make electricity, depending on the electric company. But mostly
it's coal, coal and more coal -- one billion tons a year or more.
Almost four tons a year for every one of us. Four tons! Even today."
But coal is at a crossroads. We depend on it today, and we desperately need to build more generating capacity. Should we burn more coal or do something else?
Some people say it is too dirty to burn any more and we should stop using it. Some say we can burn it cleaner and should do that. Some say we burn it clean enough now, a whole lot cleaner than we used too, clean enough. Then there is the issue of whether burning so much coal is affecting the earth's climate? And if so, how? There's lots of disagreement about that. (See Coal and Climate Change)
Some want more nuclear power plants instead, but others don't want any. Many people want to burn natural gas instead of coal, but the only extra gas is in places like Texas and Canada, a long way away and very expensive. Some say we should just use less electricity, but that is hard because it is so useful. What to do about coal is a very big question. One we all need to think about. (See Why Not Stop Burning Coal?)
For more detail:
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