[SOUND] I'd like to make a little table of what comes in and out of the coal part of Abbott power plant. So they set up the power plant to be able to handle train cars full of coal. And indeed you could a whole train car or a couple of train cars and you'd be probably fairly set for a day. The thing is that trains these days aren't just one or two cars, right. They're really, really big. And while a huge, normal scale power plant, industrial scale, type that powers huge cities, there's 400 or so of them around the United States. These coal power plants take an entire train of coal every day. Not one train car, talking 100 train cars full of coal are burned every day. Abbott power plant doesn't use train cars, it uses trucks. And around 12 trucks per day, they come at night, semi-trailer trucks, 25 tons or something like that of coal in each one, come into the power plant every day. If we look at the statistics for one year it's about 90,000 tons of coal per year. What are the other inputs to the plant? Well because of the pollution control we need to bring in gravel, limestone. There's 7,000 tons per year of limestone, of gravel, brought into the power plant. And clearly you're going to need some water, not just to make the steam, but in the whole loop of the processes. And, while you normally don't think of it, it uses a lot of air, right, it takes the air, pumps it through. Turns the carbon into carbon dioxide, that's where the oxygen comes from. So those are inputs, what about on the output side? Part of the carbon does not burn and the moving grate type of coal burners, not the most-efficient. So some of the ash will still have some carbon with it. It turns out that there are 11,000 tons of ash removed each year. The sulfur ideally has been combined with the gravel and turns into gypsum. And it's nice to know there's more gypsum coming out than there is gravel coming in. It's good. That means the rest of it was probably the sulfur that we took out of the coal. There are also 11,000 tons of gypsum taken out of the plant every year. 12 trucks come in, 12 trucks go out, maybe three or four of those trucks are filled up with either ash or gypsum. What do they do with it? Conveniently those trucks came from the coal mine, they go back to the coal mine. After all, you took all this stuff out of the ground. So you put it back in the ground. Some place obviously, where they're not still pulling the coal out of. Different part of the mine where they've already taken the coal out. Can't argue too much about it since that's where the stuff came from in the first place. Other places, maybe you landfill it. Especially the gypsum is clean, it's not going to be a pollution hazard, it's very stable. And you can use that to mix with all your other things that you might want to bind up. So, we've got the solids. But there's still a mass balance is missing here. There's still the stuff that's in the smoke. Clearly there's an enormous amount of carbon dioxide. All the carbon ideally has turned into carbon dioxide. Even though we've done a good job scrubbing out the sulphur dioxide, some is still going to go out of the plant. And you notice in this process we didn't do anything about nitrous oxide. We haven't particularly run it at a very high temperature to make it like you would in a cyclone furnace, but we still get some nitrous oxides that come out as well. There's also quite a bit of water vapor. Most of the smoke you see coming out of the chimney, the white billowing stuff is steam. This whole process water is at many, many stages of it, particularly in the pollution control stage where you're bubbling it through water. Well, a lot of that water gets picked up and taken up the smokestack as well. Everything I've listed so far, the ash, the gypsum, the CO2, the SO2, the NOX, the water vapor, are not the reason you're doing this. The reason you're doing this is to make electricity and to make steam for distribution to keep your buildings warm. So let's also talk about that. In the Abbot Power Plant from the coal side of the operation there's about 200 megawatts of thermal energy. That turns into 20 megawatts of electricity, it's about one-third efficient. So maybe that was 60 megawatts of the thermal load. But we don't put a low pressure turbine afterwards to capture the rest of that steam. After all we want that steam for district heating. We want that steam to heat the rest of the buildings on campus. And therefore there's maybe 140 megawatts of steam that goes and transverses the campus warms the buildings and comes back as water which is then reused in the whole cycle. That's a very important output of the power plant, the reason that we have it in the first place. Let's talk about the steam just a little bit more. The power plant and the buildings across the university are not right next door. The university covers a very large area. After all there's 44,000 students here, and to get the hot steam and the water back to each of these buildings, clearly it has to go through pipes. And those pipes need to go underground. You could insulate them, but if you just ran a pipe underground, you'd be heating up a lot of ground. And if anything ever broke, or you wanted to add another pipe, well, you gotta dig up the street, or dig up the sidewalk, go down, and find where the pipe is, and find where the break is. So there's a much better way. That better way is to make tunnels. They're called the steam tunnels. They're actually corridors high enough up so you can walk through them. And through those corridors are pipes, there's the steam going out and the condensate return. And since we now have a system to connect all of the buildings together, sometimes you run other things through them that need to get from one building to another. Because they're in a tunnel, the cross section of the tunnel allows insulation. So imagine if I look at a cross section, here's the tunnel and maybe along one wall, you've got these pipes connected, all right. And this is tall enough so you know you can walk through here, not hit your head. And the pipes are bringing it. And there's lots of air insulation all around here so that these pipes do not lose their heat. If you contrasted that with just the pipe going through all of the dirt, you lose heat. And here you have insulation, here you have insulation. Here you lose heat. So tunnels become a very convenient way to connect the things in campus in an efficient manner. Since the system is very old, occasionally pipes start leaking or need replacement. You can walk through there and fix it all. You can inspect it on a almost daily basis to make sure there are no steam leaks or other problems going on. As the university grew, the electric use and needs for the university grew as well. You can buy electricity, of course, from the local utility. But since we're a large sole user there was a thought that how about if we just expand our power plant. Could we expand the power plant and in time, since we're generating our own electricity save money as compared to buying electricity that someone else paid for? And if you have the capital to make that investment, clearly the answer is usually yes. So, the university did indeed install a new power plant, a new part of the power plant that makes an additional 40 or more megawatts of electricity. This addition to the power plant uses natural gas. Just like the rest of the electric capacity growth in the US has been from natural gas, the capacity growth in the university has also been from natural gas. These are natural gas combine cycle turbines. The gas and air come in, they're burned, the hot exhaust gases spin a turbine, and you make electricity. Those gases don't get all the way cooled off in this process, so then those gases go through a heat exchange unit and make steam. That steam could, of course, be added to the steam system throughout campus. Or you can run it through a turbine, a combined cycle, another cycle and get more electricity out of it. In the end, the gases are simply carbon dioxide and water vapor and they go up the smokestack, short little smoke stacks. The ones that don't need pollution control, because you're not putting anything out of them other than carbon, vapor, and carbon dioxide. Burning natural gas becomes a much simpler and when you use a combined cycle, a more efficient way to make electricity. Unless the price of gas is too high. In 2007, when natural gas prices went through the roof, specially in the Midwest of the United States in the winter. They looked at the price tag coming in for the natural gas, then they looked the number of megawatts electricity they were making. It was amazing that there was a time period where gas was so expensive it was cheaper to buy the electricity from someone else. Talk about an expense. Forget about paying back your capital expense, forget about operational expense, forget about all this, you just can't afford to buy the fuel. Buying electricity from the utility was cheaper. Now, of course, gas prices came back down, and we're back to generating our own electricity. And these days, with the advent of hydraulic fracturing, there are large supplies of natural gas. The price has dropped even further, and it looks like a brilliant idea, having made the natural-gas fired plant at the university because we're generating electricity at a much cheaper rate than we could buy it today. That's what you need to know about Abbott coal power plant. [MUSIC]
