This is a continuation of Energy 101 and today we're going to look at energy
sources, where we get the energy from that we so desperately want, that we've
talked about before. And today we're going to hone in on coal.
we see from our pie chart from previously that 20% of our energy that we use comes
from coal, 26% from natural gas, 36% from oil, nuclear 9%, and then we have some
renewables. biomass and hydro being the major ones.
Biomass is burning of lot of, waste coming out of the paper pulp and paper
plants for instance. and then you have wind and geothermal and
solar. you notice solar is about 6 times less
than wind. That's because of economics, generally.
So today we're going to talk about coal and where it comes from and how we get it
and what some of the characteristics are. what is coal? Well, coal is a solid
chunk, and coal by the way was the fuel that followed wood.
Wood was the first energy that caveman used to started cooking his food with
wood, and then coal came into play and we started getting more and more of our
energy from coal. coal is an organic sedimary, seditenmary
rock, it forms mainly from plant debris over thousands of years.
and it consists mainly of carbon. Coal doesn't have any hydrogen in it.
We still include it in hydrocarbons, which indicates it's got both carbon and
hydrogen. the other fossil fuels do have hydrogen
in them but coal only has carbon in it. So it, it's, some people like to think
that coal is being renewed and oil and gas is being renewed over time, which it
is, but at a very, very, very slow rate. It's just infinitesimal how fast it's
being formed to compared to how fast we're using it.
That's so it, it's definitely a finite resource from the time scale that, that
we are using it. so that's some of the basic
characteristics of coal. what do we do with it? As all the fossil
fuels that we use today, we react the carbon that's in the coal with oxygen
that's in the air. And that forms CO2 and the chemical
energy on the right hand side of the equation is less than the chemical energy
of the 2 independent molecules of the left hand side.
That means we're releasing the chemical energy content.
And it is being released as heat, or comes off as a flame.
And of course, the flame is hot, and we get heat from it.
We can heat our homes with it, we can make steam, we can cook with it, etc.
so how do we get this coal? Well, there are two basic means by which we get coal.
One is open mines in which we just go from the top of the Earth, and dig dig
down in an open pit, and mine it out of the open mine.
And then there are underground mines. We started primary with underground
mines. and coal miners worked underground for
long hours and in order to extract coal from underground mines.
This is just a shot of one of the shafts going down into a coal mine.
There are many coal miners, particularly, in the winter months, in the Northern
Hemisphere, never see the light of day. When they're, during the days they're
working they go down in the mines before sun comes up and, come, they come back
after the sun has set. So it's it's a difficult working
environment. it's, it's methane, will tend to be
released as you mine the coal and break open the, break the coal away from the
walls. And you have to be careful with that.
It can cause explosions. The dust from the coal can, can cause
explosions. Coal dust explosions, and you breath the
coal dust is not good for your lungs. So it's a difficult working environment.
They've gone recently a lot to open pit mining.
Here's an open pit that's shown from just dug down and you have roads that wind
down into the bottom of the mine, and they clear off the dirt from the top of
the coal and then go down and dig the coal out with big shovels such as, well,
such as this. And, load it onto mining trucks.
And haul it back up out of the mine to the surface, and then put it on
trains and carry it away. this is another shot of of a rena, a,
open pit coal mine on the left that has been closed and has been restored.
Of course, the dirt hasn't been put back on, it's been pushed off into the
valleys. But the grass, as you can see has been
planted there. And on the right hand side we have some
active open pit coal mines. And you get residue ponds first, and you
get water that comes out that's got arsenic's and mercury poisons in them.
So it's the coal is a difficult fuel from a, from an environmental impact on
getting it out of the ground no matter which way we go, whether it's underground
and through mines. Underground mines or an open pit mining.
it comes out of the mines or the, or the, open pits and it's put on trains.
train hauling, train, companies, railroad companies rely substantially on the base
business of just hauling coal. from the mines to the power plants.
Electric power plants is where most of the coal is being used we'll see in just
a minute and during a, for the summer months in particular when the coal power
plant is running wide open, which is not unusual since they're the last power
plant could generally be shut down when the demand decreases.
They they're using about 100 train load cars of coal a day.
So you have to bring in a hundred coal cars such as these everyday to keep the
power plant supplied with fuel. So it's a massive operation.
That's just for one coal power plant, electric power plant.
But it's a major, major industry both on the mining side, the transport side, and
of course the power plant side. We'll look at some of the missions
characteristics of the different fuels. We'll hold that to talk about the
environmental impacts in general seperately.
But coal is a actually one of the few and basically the only one of any, any
significant numbers that we export. We actually export about 8% of the coal
that we mine and all, so all of the coal that we consume is produced in the US.
Here domestically and we actually are, actually mine about 8% more that is
shipped out to other countries for their use.
So we're, we're totally independent of other nations regarding Coal unlike oil,
which we'll see later on. how do we use the coal? As I mentioned,
most of it's used for electric power plants.
about 93% is used for going to these power plants where they can use 100 train
loads of coal a day, industry for [UNKNOWN].
Reasons in general, use about 6.5% and commercial buildings actually are some of
them still heated by coal. Very very few percentage, it's such a
handling problem to get the coal into the basement of the building and put it into
a furnace and create the steam that goes around the building to heat it.
But that, those were the primary utilizations in use that we have.
Where the coal goes. One thing I wanted to mention, that I
didn't say earlier. And that is, is that, on the, there's a
different environmental impact other than the air emissions that come off of
burning the coal. once the coal is burned you have ash,
coal ash that's got arsenics and mercury in it, and poisons in their solid
particles from, that, that, that don't burn and they have to get rid of them
from the boiler. The, and the firebox and they put them in
ponds. And, these are ta, toxic hash bonds, coal
has bonds. And every once an a while, 1 will
rupture. And, the pond will break, the pond will
break that holds it in. And when, this happened about 5 years ago
with TVA. And this is a picture of, of, where a
house was almost covered up by these, by this ash pond spill.
it's a terrible toxic situation. It polluted the river that it obviously
ran into. it's just one more aspect to coal that we
have to worry about and deal with. Thank you.
We'll talk about the natural gas next time.