1 00:00:00,012 --> 00:00:07,145 Hello, back to Energy 101. And today we are looking at electric power 2 00:00:07,145 --> 00:00:12,404 plant capacity factor. This is another major characteristic we 3 00:00:12,404 --> 00:00:18,155 need to study, and be aware of when we're dealing with utilization of electricity 4 00:00:18,155 --> 00:00:22,560 from the grid. And essentially, I don't know, 99% or 5 00:00:22,560 --> 00:00:26,020 more, of our electricity comes from the grid. 6 00:00:26,020 --> 00:00:32,336 That's the, basically a pool that has many power plants feeding into it. 7 00:00:32,336 --> 00:00:40,136 Renewable energy photovoltaics, renewable energy, wind generators hydroelectric 8 00:00:40,136 --> 00:00:46,497 dams, nuclear coal plants, gas plants, they all feed into the same grid. 9 00:00:46,498 --> 00:00:51,823 And then at the other end, we pull out some electricity and the, the power plants 10 00:00:51,823 --> 00:00:55,506 are turned on and off, and up and down, to meet our demand. 11 00:00:55,506 --> 00:01:02,596 So but the demand varies. And so, what does the demand that's placed 12 00:01:02,596 --> 00:01:09,551 on the grid, that the utility servicing the grid, and managing the grid, has to 13 00:01:09,551 --> 00:01:13,462 deal with. Well time of day is an obvious one. 14 00:01:13,463 --> 00:01:18,309 It, the peak demands, peak electricity usage is during the day. 15 00:01:18,310 --> 00:01:23,821 And the lowest is at night. Two, three o'clock in the morning, most 16 00:01:23,821 --> 00:01:29,113 factories are closed down, office buildings are closed down, homes are 17 00:01:29,113 --> 00:01:34,280 closed down, people are asleep, and so the electricity usage is low. 18 00:01:34,280 --> 00:01:38,496 Temperatures are low, by the way, and therefore even air conditioners are, lower 19 00:01:38,496 --> 00:01:41,544 than the daytime, in the South, for instance, summertime. 20 00:01:41,544 --> 00:01:47,264 So the air conditioners are unloaded even. But they all, it also changes by day of 21 00:01:47,264 --> 00:01:52,064 week, that you might not think of at first, because weekdays, Monday through 22 00:01:52,064 --> 00:01:57,164 Wednesday, have a higher demand, and have a different profile than weekends, 23 00:01:57,164 --> 00:02:02,117 Saturday and Sunday. So, the, utilities have to be prepared to 24 00:02:02,117 --> 00:02:08,441 operate differently on Saturdays and Sundays, and weekend days, than during the 25 00:02:08,441 --> 00:02:14,437 weekdays, Monday through Friday. But they also vary may, in another major 26 00:02:14,437 --> 00:02:18,170 way, and that is over a longer term, by seasons. 27 00:02:18,171 --> 00:02:23,539 The Winter and Summer, have a higher demand than the Fall and the Spring. 28 00:02:23,539 --> 00:02:28,910 And of course the reason for that is, the Fall and the Spring have a low heating 29 00:02:28,910 --> 00:02:34,404 need for the space heating, when the temperatures are, are 70 degrees, or the 30 00:02:34,404 --> 00:02:40,185 are fairly comfortable outside, that we have to provide less space heating for our 31 00:02:40,185 --> 00:02:44,109 buildings, and our homes, than we do in the Winter. 32 00:02:44,109 --> 00:02:49,806 And in the Summers, we have to provide air conditioning, in the Summers, for space 33 00:02:49,806 --> 00:02:53,140 conditioning. Fall and the Spring, we don't have to 34 00:02:53,140 --> 00:02:58,348 supply as much air conditioning. So, you have variations, short term 35 00:02:58,348 --> 00:03:05,386 variations, from hour to hour in the day, daily variations from day of week, and 36 00:03:05,386 --> 00:03:10,637 seasonal variations with Winter, Summer, Fall, Spring. 37 00:03:10,638 --> 00:03:16,986 So the su, utility managing the grid, has to deal with all of these ups and downs, 38 00:03:16,986 --> 00:03:22,506 and be able to meet the highest demand that people ask for, when they turn 39 00:03:22,506 --> 00:03:28,486 something on, and they also have to throttle things down, when the dam, demand 40 00:03:28,486 --> 00:03:32,930 is low, because there's no electrical storage system. 41 00:03:32,930 --> 00:03:37,748 Electrical storage is very expensive and it isn't commercially viable at this 42 00:03:37,748 --> 00:03:40,970 point. Hopefully it will be in the future, but 43 00:03:40,970 --> 00:03:44,905 electricity can, is, can only be generated if people use it. 44 00:03:44,906 --> 00:03:51,014 So everything's gotta match up. Let's, talk, look at this a little more 45 00:03:51,014 --> 00:03:56,096 closely, and before we do that, we need to look at some definitions. 46 00:03:56,096 --> 00:04:01,598 Power capacity of a power plant, or a fleet of power plants, either way, is the 47 00:04:01,598 --> 00:04:04,920 maximum steady power production capability. 48 00:04:04,920 --> 00:04:09,000 Maximum being the running wide open as they're designed to do. 49 00:04:09,000 --> 00:04:13,725 It's not like the car trying to run it wide open at a 120 miles per hour, and you 50 00:04:13,725 --> 00:04:18,760 probably can't do that very long before you damage something in a lot of cars. 51 00:04:18,760 --> 00:04:24,392 But these are, this is industrial equipment that is designed to operate with 52 00:04:24,392 --> 00:04:30,204 maxium power, rated power, in a, steady state, for days, or months on end. 53 00:04:30,205 --> 00:04:35,417 That's the maximum, capacity, or what we call the power capacity. 54 00:04:35,418 --> 00:04:42,741 Now that's like speed on your speedometer. In other words, it's measured in Mega 55 00:04:42,741 --> 00:04:51,211 Watts, which we denote by MW, and we or Kilo Watts, which is denoted by Kilo 56 00:04:51,211 --> 00:04:56,137 Watts. Of course, a Mega Watt is a million Watts, 57 00:04:56,137 --> 00:05:01,420 and Kilo Watt is a 1000 Watts. And that's the rate at which we're using 58 00:05:01,420 --> 00:05:06,223 the energy. Like miles per hour on your, in your car. 59 00:05:06,224 --> 00:05:11,777 And it's the, we denote the maximum capacity, that the power plant, or the 60 00:05:11,777 --> 00:05:17,783 fleet of power plants, if it's to look at all of them feeding into the grid, we 61 00:05:17,783 --> 00:05:24,244 denote that by MW, capacity, subcapacity, or Kilo Watts of capacity, just depending 62 00:05:24,244 --> 00:05:30,594 on whether you want which units you want. Ones just a thousand different than the 63 00:05:30,594 --> 00:05:34,314 other. So that's the power capacity that, and so 64 00:05:34,314 --> 00:05:40,455 and, that needs to be of course higher, a little bit higher, than the maximum demand 65 00:05:40,455 --> 00:05:46,063 that the system will ever see. Otherwise we have blackouts and brownouts, 66 00:05:46,063 --> 00:05:50,124 and equipment gets overloaded and the system falls apart. 67 00:05:50,125 --> 00:05:56,875 But, another definition, that we'd like to look at, is the electrical energy 68 00:05:56,875 --> 00:06:01,550 production. That's comparable, using the speed analogy 69 00:06:01,550 --> 00:06:07,259 on, in a car, to the miles analogy. If the power that we're using, times the 70 00:06:07,259 --> 00:06:13,155 time we use it, that gives us the energy used, that determines how much fuel we've 71 00:06:13,155 --> 00:06:19,051 got to put in and how long we have to run the plant, and how hard we have to run the 72 00:06:19,051 --> 00:06:21,808 plant. So in other words, it's the electrical 73 00:06:21,808 --> 00:06:24,897 energy used typically, we always say, over one hour. 74 00:06:24,898 --> 00:06:31,492 So it's measured in Mega Watt hours, MW hours, or Kilo Watt hours, KW hours. 75 00:06:31,493 --> 00:06:36,490 And that gives us the amount of energy that is used over some period of time. 76 00:06:36,490 --> 00:06:42,338 And for, pow, Capacity factor, we generally look at a whole year. 77 00:06:42,338 --> 00:06:47,780 And so the, the annual load factors determined by the looking at the annual 78 00:06:47,780 --> 00:06:53,220 electrical energy production over years, denoted by Mega Watt hours per year, or 79 00:06:53,220 --> 00:06:57,406 Kilo Watt hours per year. Typically Mega Watt hours per year, 80 00:06:57,406 --> 00:07:02,506 because there are a lot of Kilo Watt hours that are produced over a year, even by one 81 00:07:02,506 --> 00:07:06,058 power plant. So those are the basic definitions. 82 00:07:06,059 --> 00:07:11,700 Moving, further on definitions, what are the, the capacity factor, which is the 83 00:07:11,700 --> 00:07:16,580 whole point here, in discussing, is to find, as the Mega Watt hours that is 84 00:07:16,580 --> 00:07:22,020 produced in one year, and this is for one power plant, if you looked at the capacity 85 00:07:22,020 --> 00:07:27,140 factor of a power plant, or through a whole fleet of power plants feeding into 86 00:07:27,140 --> 00:07:31,267 the grid. You can do it nationally, you can do it 87 00:07:31,267 --> 00:07:38,222 for just a, a region or one utility that and, one part of the grid that has, is 88 00:07:38,222 --> 00:07:44,412 under control by one utility. Then that is divided by the Mega Watts 89 00:07:44,412 --> 00:07:50,901 capacity, that, that, that the power, power, plants are capable of, pro, 90 00:07:50,901 --> 00:07:55,453 producing, if they run wide open, times 8760 hours. 91 00:07:55,454 --> 00:08:03,074 Now whats the 8760 hours? Well, 807, 8760 hours, is the number of 92 00:08:03,074 --> 00:08:08,002 hours in a year. So, in other words, if the plant, the 93 00:08:08,002 --> 00:08:14,307 denominator, is the number of Mega Watt hours that the power plant, or fleet of 94 00:08:14,307 --> 00:08:20,903 power plants, could produce if they ran wide open, to, at rated maximum capacity, 95 00:08:20,903 --> 00:08:25,765 for every hour of the year. So that's what the denominator is. 96 00:08:25,766 --> 00:08:32,164 The numerator is, of course, the actual amount that is produced. 97 00:08:32,164 --> 00:08:38,374 So that, the number is always less than one, due to the fact that the capacity has 98 00:08:38,374 --> 00:08:44,594 got to be equal to the maximum demand put on the system, over the entire year. 99 00:08:44,595 --> 00:08:49,580 And that many period, most periods of the year, and hours of the year, the demand is 100 00:08:49,580 --> 00:08:54,009 going to be less than that. So, it's not producing, fully, every hour 101 00:08:54,009 --> 00:08:58,830 of the year, so the numerator was going to be less than the denominator. 102 00:08:58,830 --> 00:09:04,088 So, it measures electricity produced as a fraction of the electrical energy it could 103 00:09:04,088 --> 00:09:08,200 have produced by running maximum, output every hour of the year. 104 00:09:08,200 --> 00:09:11,070 So that's the definition of the capacity factor. 105 00:09:11,070 --> 00:09:16,631 By the way, let me note here, that there's also a term that you, some of you might be 106 00:09:16,631 --> 00:09:22,080 familiar with, called the load factor. And, in the load factor definition, the, 107 00:09:22,080 --> 00:09:25,190 there's a small difference, hopefully small. 108 00:09:25,190 --> 00:09:32,228 In most cases the meh, denominator is not Mega Watt capacity, but the peak load seen 109 00:09:32,228 --> 00:09:36,595 throughout the year. And the power plant capacity needs to be 110 00:09:36,595 --> 00:09:41,470 slightly greater than the maximum load at the system, or power plant ever sees 111 00:09:41,470 --> 00:09:44,516 during the year in order to stay 10% higher. 112 00:09:44,517 --> 00:09:50,974 In order to maintain control of the, and be able to keep from going unstable, for 113 00:09:50,974 --> 00:09:54,230 stability purposes. So some nuances there. 114 00:09:54,230 --> 00:10:00,040 But capacity factor, and load factor, are very similar, except the capacity factor 115 00:10:00,040 --> 00:10:05,601 will always be a little bit lower than the load factor, because the used Mega Watt 116 00:10:05,601 --> 00:10:11,070 peak demand during the year Rather than the Mega Watt capacity of the system. 117 00:10:11,070 --> 00:10:15,230 So, let's look at an example there. Well, let's take a nuclear power plant. 118 00:10:15,230 --> 00:10:21,215 Nuclear power plants, I picked that one because that one has the, largest, 119 00:10:21,215 --> 00:10:26,628 highest, capacity factor. And take a large, two unit, typically, 120 00:10:26,628 --> 00:10:33,303 they're built in thousand Mega Watt units, and if you take a two unit nuclear plant, 121 00:10:33,303 --> 00:10:39,533 that has the capability of producing 2,000 Mega Watts on a continuous basis, that's 122 00:10:39,533 --> 00:10:43,557 the capacity. And let's assume that they, you measure 123 00:10:43,557 --> 00:10:49,609 the actual output over, of that plant over the year, and it was 15 million Mega Watt 124 00:10:49,609 --> 00:10:53,222 hours. That's the actual energy is produced. 125 00:10:53,222 --> 00:11:00,902 But it could produce how much? It could produce 2,000 Mega Watts times, 126 00:11:02,050 --> 00:11:07,347 times 8,760 hours. That's the, what it could have done, but 127 00:11:07,347 --> 00:11:12,128 it actually did 15 million. Well if you run the numbers out I believe 128 00:11:12,128 --> 00:11:16,575 you get an 86% capacity factor. Well that's a high capacity factor, but in 129 00:11:16,575 --> 00:11:19,130 fact, nuclear plants typically run about 90%. 130 00:11:19,130 --> 00:11:23,154 And there's several reasons for that but that's, well number one it shows the 131 00:11:23,154 --> 00:11:28,244 reliability, the maintianance. They're down for maintenance, around 1% of 132 00:11:28,244 --> 00:11:31,840 the time. And that's scheduled maintenance. 133 00:11:31,840 --> 00:11:35,800 You hopefully don't have unscheduled maintenance, particularly in a nuclear 134 00:11:35,800 --> 00:11:39,624 plant, but you may have. As any plant may have some unscheduled 135 00:11:39,624 --> 00:11:44,730 maintenance where something goes wrong, and that you weren't prepared for and 136 00:11:44,730 --> 00:11:48,530 didn't expect. If you expected it, you replaced that 137 00:11:48,530 --> 00:11:53,970 part, or did the maintenance during the annual maintenance period, when you take 138 00:11:53,970 --> 00:11:58,671 the plant down for maintenance. So nuclear plants are pretty well 139 00:11:58,671 --> 00:12:02,180 base-loaded. The fuel cost is very low compared to 140 00:12:02,180 --> 00:12:06,826 fossil fuels. And therefore they can run them if you're, 141 00:12:06,826 --> 00:12:12,810 they already got them built and they want to run them rather than running a coal 142 00:12:12,810 --> 00:12:17,128 fired or gas plant, where they have to buy fuel for it. 143 00:12:17,128 --> 00:12:24,712 So, but if you look at the US fleet as a whole, if you take the entire capacity, of 144 00:12:24,712 --> 00:12:32,806 all power plants in the US, and add them together, and divide it and divide that 145 00:12:32,806 --> 00:12:40,558 into the annual Mega Watt hours that are produced and used in the country, then you 146 00:12:40,558 --> 00:12:47,555 come out with a 40 to 50% capacity factor. Now, what that means is, and this is my 147 00:12:47,555 --> 00:12:53,250 whole point here, is that only about less than half of the US power plant capacity 148 00:12:53,250 --> 00:12:57,402 is used at any one point in time. On, on the, on the average, excuse me, on 149 00:12:57,402 --> 00:13:00,075 the average. Over the average of a year, we're 150 00:13:00,075 --> 00:13:03,901 utilizing half of the, or less, of the power plant capacity. 151 00:13:03,901 --> 00:13:10,134 Sometimes, it's 20, 30 percent. Other times, or a few hours, normally, 152 00:13:10,134 --> 00:13:14,973 it's, like, 90%. But over average, so we had, it was only 153 00:13:14,973 --> 00:13:18,222 40 to 50. So we got a lot of excess capacity, except 154 00:13:18,222 --> 00:13:22,725 during the peak hours in the year. Which normally occurs during the hottest 155 00:13:22,725 --> 00:13:25,699 afternoons, late afternoons, in the summer. 156 00:13:25,700 --> 00:13:29,020 When there's a very large air conditioning demand. 157 00:13:29,020 --> 00:13:31,743 That's generally when your annual peak will occur. 158 00:13:31,744 --> 00:13:36,433 So, let's look at power plant dispatchings. 159 00:13:36,433 --> 00:13:41,782 So, how do you, how does the utility that has this fleet of powerplants that they 160 00:13:41,782 --> 00:13:47,776 can turn up and down, like throttle, like your accelerator on your car, which ones 161 00:13:47,776 --> 00:13:53,203 do they throttle back, and which ones do they turn on and turn off when they don't, 162 00:13:53,203 --> 00:13:56,127 don't need them? You got a big choice there. 163 00:13:56,128 --> 00:14:01,080 So which half do you use, and which half on average do you throttle down, or turn 164 00:14:01,080 --> 00:14:04,136 off. Well you turn on generating facilities 165 00:14:04,136 --> 00:14:09,419 that are the cheapest to operate, in terms of dollars per, per Mega Watt hour. 166 00:14:09,420 --> 00:14:14,458 In other words the, in, which, you already paid for the capital costs, and so you got 167 00:14:14,458 --> 00:14:19,037 to amortize the capital costs over the year, whether it's running or not. 168 00:14:19,038 --> 00:14:23,794 That's the fixed cost, it's fixed. The capital cost is fixed, so the, the 169 00:14:23,794 --> 00:14:29,758 incremental costs in dispatching, if, if it gets about what the plant costs to 170 00:14:29,758 --> 00:14:35,554 build, because you've already got money invested, and so you now deciding whether 171 00:14:35,554 --> 00:14:39,755 to run it, or run plant, power plant one, or power plant two. 172 00:14:39,755 --> 00:14:45,233 And, so in both cases you crank, you look at the dollars per Mega Watt hour to turn 173 00:14:45,233 --> 00:14:50,794 it on, versus let it sit there and do nothing and, and that's the, basically the 174 00:14:50,794 --> 00:14:55,204 fuel cost. So, typically the plants that are turned 175 00:14:55,204 --> 00:15:01,563 on first, and turned off last, will be the ones with the lowest fuel cost. 176 00:15:01,563 --> 00:15:05,712 Well, it's pretty obvious that the ones with the lowest fuel costs are the 177 00:15:05,712 --> 00:15:08,378 renewable energy, because that's energy's free. 178 00:15:08,378 --> 00:15:12,858 So, the wind, solar and hydro is used anytime it's available. 179 00:15:12,858 --> 00:15:17,967 And that's, I mean, all you gotta do is, is look at the reality, and that is 180 00:15:17,967 --> 00:15:21,790 typically what happens. There are a few isolated cases where 181 00:15:21,790 --> 00:15:26,206 there's some grid limitations, and some contracts, that happened out in the 182 00:15:26,206 --> 00:15:31,161 northwest a couple summers ago, I believe, where the grid became overloaded. 183 00:15:31,162 --> 00:15:37,098 And coming from a certain region, and due to contractual obligations, they actually 184 00:15:37,098 --> 00:15:41,416 turned off some wind farms, but that's a very unusual situation. 185 00:15:41,417 --> 00:15:46,990 Basically in that same category, though, is nuclear, because, not only is the fuel 186 00:15:46,990 --> 00:15:52,362 cost from nuclear very low, but also they're much more difficult to turn on and 187 00:15:52,362 --> 00:15:55,110 off. You have to turn, turn them up and down 188 00:15:55,110 --> 00:15:58,680 very slowly. It takes days to crank up a nuclear plant, 189 00:15:58,680 --> 00:16:01,458 and turn it, turn it down, and turn it off. 190 00:16:01,458 --> 00:16:04,938 So, you have to consider that. Another factor, by the way, and these are 191 00:16:04,938 --> 00:16:08,814 second and third order effects, but the other factors that come into play is water 192 00:16:08,814 --> 00:16:11,300 usage. In some cases, the minimum, they got 193 00:16:11,300 --> 00:16:15,870 minimum water flows that the plant uses, and maximum water flows and things. 194 00:16:15,870 --> 00:16:20,154 And depending on what's going on in the river, where they're dumping their, their 195 00:16:20,154 --> 00:16:23,060 heat, if they are, then that can come into play. 196 00:16:23,060 --> 00:16:27,060 But basically, the renewable energy in the nuclear run all the time. 197 00:16:27,060 --> 00:16:30,227 It's what we call base load. Next come coal. 198 00:16:30,228 --> 00:16:33,284 Because coal has normally been cheaper than gas. 199 00:16:33,285 --> 00:16:38,878 And next comes natural gas plants. Now that's recently, in this year, that 200 00:16:38,878 --> 00:16:43,072 has changed for the first time, in my 35, 40 year history. 201 00:16:43,073 --> 00:16:48,197 That natural gas plants have been cheaper, or as cheap to run as coal plants. 202 00:16:48,198 --> 00:16:52,882 And so they have actually shut down some coal plants before shutting down gas 203 00:16:52,882 --> 00:16:56,854 plants. But, they, that probably won't last too 204 00:16:56,854 --> 00:17:03,029 long, because gas prices are already headed back up, and coal is fairly stable 205 00:17:03,029 --> 00:17:07,180 at this point. So, we expect it, that the old rule that 206 00:17:07,180 --> 00:17:13,255 gas plants, or the natural gas plants are the first ones to turn off or turn down, 207 00:17:13,255 --> 00:17:19,600 will, will be the, is has been, generally in the past, except in some unique periods 208 00:17:19,600 --> 00:17:25,428 or in situations, and probably will continue over, over the, future. 209 00:17:25,428 --> 00:17:29,156 So that's how we dispatch, our, the plants. 210 00:17:29,157 --> 00:17:35,481 The coal an, the note, the coal and gas have switched depending on relative price, 211 00:17:35,481 --> 00:17:42,124 and need to note that, because, you can, you can find examples right now that, that 212 00:17:42,124 --> 00:17:46,716 is not the case. But in general, it's not, that, that is 213 00:17:46,716 --> 00:17:52,050 the sequence used. And that, that covers the dispatching. 214 00:17:52,050 --> 00:17:57,357 And the one reason that I wanted to do that is regarding, where do we get our 215 00:17:57,357 --> 00:18:01,692 incremental load from? And it's a major characteristic of 216 00:18:01,692 --> 00:18:07,775 electrical power that's fed into the grid, and we're going to discuss the, emissions 217 00:18:07,775 --> 00:18:12,989 from electric cars, and so you need, you need to know something about where that 218 00:18:12,989 --> 00:18:18,440 electricity will come from as you put in, put on one car additional electric car for 219 00:18:18,440 --> 00:18:23,812 recharging onto the grid, or put a million of them if you got a, trying to determine 220 00:18:23,812 --> 00:18:29,105 how much impact a tax credit will give for our subsidy to get a lot of, a million new 221 00:18:29,105 --> 00:18:32,711 electric cars out there on the system and whatever. 222 00:18:32,712 --> 00:18:40,139 So, that gives us the background, and one more important characteristic of the 223 00:18:40,139 --> 00:18:46,804 electrical power plants, that we operate, and utilize, and depend on every day. 224 00:18:46,804 --> 00:18:47,633 Thank you.