1 00:00:00,012 --> 00:00:08,427 Energy 101, we've been talking about the natural resources that we have to drive 2 00:00:08,427 --> 00:00:16,817 our energy system and we've been, been talking essentially about fossil fuels, 3 00:00:16,817 --> 00:00:23,790 coal, natural gas, oil and, so let's, let's look at some renewables like solar. 4 00:00:23,790 --> 00:00:27,761 Today we're going to want to look at solar energy resources. 5 00:00:27,761 --> 00:00:32,908 it's a new ball game when you start talking about solar and wind and, as 6 00:00:32,908 --> 00:00:39,792 renewable resources because with coal and oil and gas and that kind of fossil fuel 7 00:00:39,792 --> 00:00:46,747 is very convenient, you can just fire up your, your plant, whatever you're fueling 8 00:00:46,747 --> 00:00:48,252 with those. Fuels. 9 00:00:48,252 --> 00:00:52,507 And crank 'em up and run 'em wide open. You control the throttle, so to speak. 10 00:00:52,507 --> 00:00:55,112 You can run 'em wide open, you can let 'em idle. 11 00:00:55,112 --> 00:00:58,222 You can, just like your car. And you have total control. 12 00:00:58,222 --> 00:01:01,917 That's what we call dispatchable in the electric utility industry. 13 00:01:01,917 --> 00:01:06,572 But in, whether it's your, your home furnace, you can turn Turn it up and down 14 00:01:06,572 --> 00:01:11,278 and keep your home just the right temperature, but when you have solar and 15 00:01:11,278 --> 00:01:16,318 wind, the sun doesn't shine so brightly all the time, and the wind doesn't blow 16 00:01:16,318 --> 00:01:21,052 strongly all the time. So it's, we have to make sure that our, 17 00:01:21,052 --> 00:01:27,577 the way we use these renewable energy systems can accommodate that up and down 18 00:01:27,577 --> 00:01:30,747 resource. And that it comes and goes. 19 00:01:30,747 --> 00:01:36,427 In the case of solar, of course, it The sun only shines on the average of about 20 00:01:36,427 --> 00:01:39,607 12 dollars a day. And doesn't shine any at night. 21 00:01:39,607 --> 00:01:43,798 So that's the problem right there. and then you have clouds. 22 00:01:43,798 --> 00:01:48,615 But the, how much solar energy is there available? We're looking at it as a 23 00:01:48,615 --> 00:01:51,504 resource here. That the striking the Earth. 24 00:01:51,504 --> 00:01:55,504 That we can figure out, so we can figure out how much there is. 25 00:01:55,504 --> 00:02:00,167 And then we can determine. How to use that energy to strike in the 26 00:02:00,167 --> 00:02:03,267 earth. But, there's about 300, at noon on a 27 00:02:03,267 --> 00:02:08,092 clear day, so if you've got no clouds, it's a nice bright shiny day. 28 00:02:08,092 --> 00:02:13,250 And at noon, and the reason it has to be at noon is because that's When the 29 00:02:13,250 --> 00:02:18,089 distance that the sun has to travel through the earth's atmosphere is the 30 00:02:18,089 --> 00:02:23,201 shortest, you can imagine when it's over at an angle, in ea, early morning or 31 00:02:23,201 --> 00:02:27,893 late, it's shining at an angle ,uh, on you through a longer distance of 32 00:02:27,893 --> 00:02:31,868 atmosphere gases. And, that attenuates the sun somewhat so 33 00:02:31,868 --> 00:02:37,512 it's always brightest at noon, assuming there no clouds, because that's when the 34 00:02:37,512 --> 00:02:41,937 Path link through the, the, the atmosphere is the shortest. 35 00:02:41,937 --> 00:02:48,031 So, we, at noon and on a clear day with no clouds and low, low water moisture, if 36 00:02:48,031 --> 00:02:51,592 you look directly at the sun and point a surface. 37 00:02:51,592 --> 00:02:56,876 Direct one square foot pointed directly at the surface, so that it's 38 00:02:56,876 --> 00:03:00,519 perpendicular to the surface, to the sun rays. 39 00:03:00,519 --> 00:03:05,654 You'll get about 300 BTUs per hour falling on that one square foot. 40 00:03:05,654 --> 00:03:09,832 Or in metric units, is one kilowatt per square meter. 41 00:03:09,832 --> 00:03:14,055 And they're about 10 square feet in a square meter. 42 00:03:14,055 --> 00:03:19,249 So there's about a tenth of a kilowatt per square foot. 43 00:03:19,249 --> 00:03:23,497 If you want in kilowatt units or 300 BTU's per hour. 44 00:03:23,497 --> 00:03:28,998 Falling on 1 square foot. So that's, that's the best you can do at, 45 00:03:28,998 --> 00:03:33,680 at noon on a clear day. But now it's decreased by clouds and the 46 00:03:33,680 --> 00:03:36,692 angle from early morning to late afternoon. 47 00:03:36,692 --> 00:03:41,957 So life gets complicated whereas when we're trying to calculate even how much 48 00:03:41,957 --> 00:03:46,917 solar energy is available as a resource. But the good thing is it's free. 49 00:03:46,917 --> 00:03:52,292 We don't have to pay anybody for it. Like we do, fossil fuels in particular. 50 00:03:52,292 --> 00:03:58,149 Affordable tax is, really come on the forefront with, dropping costs in the 51 00:03:58,149 --> 00:04:02,427 last couple of years. And this is just showing 1 installation 52 00:04:02,427 --> 00:04:06,315 on a house roof fairly that's fairly typical on a house. 53 00:04:06,315 --> 00:04:09,398 When I say typical, it's a typical good one. 54 00:04:09,398 --> 00:04:13,382 The house is obviously, and, looks like design 4. 55 00:04:13,382 --> 00:04:19,368 the collectors, the house was oriented so it's facing south. 56 00:04:19,368 --> 00:04:25,796 And, and the angle of the roof was such that it collects the most energy 57 00:04:25,796 --> 00:04:32,122 sunlight, over a year. so, the, thee, this, the best angle. 58 00:04:32,122 --> 00:04:37,237 The tilt, because the sun, and, depending on the time of year, is either high in 59 00:04:37,237 --> 00:04:41,659 the sky, or low in the southerly direction, if you're in the Northern 60 00:04:41,659 --> 00:04:44,941 Hemisphere. But the, ee, for the best annual solar 61 00:04:44,941 --> 00:04:50,073 resource falling on your collectors, you want to face the collectors due south, 62 00:04:50,073 --> 00:04:55,215 and you want to tilt them up from the horizontal Of, a, the, the, number 63 00:04:55,215 --> 00:05:01,578 degrees equal to your latitude. In Atlanta, where I am, the, our latitude 64 00:05:01,578 --> 00:05:07,916 is 35 degrees, so to get the most solar energy falling on a flat fixed surface, 65 00:05:07,916 --> 00:05:12,702 we tilt the, the collectors in the southernly direction. 66 00:05:12,702 --> 00:05:18,108 35 degrees, of course on the equator a horizontal collector will collect the 67 00:05:18,108 --> 00:05:22,171 most sunlight over a year, and this is on an annual basis. 68 00:05:22,171 --> 00:05:27,182 If you're trying to optimize it for January and you don't care about the 69 00:05:27,182 --> 00:05:30,305 summertime, then the angles are different. 70 00:05:30,305 --> 00:05:34,118 If you wanted. Optimize in July, then the angles are 71 00:05:34,118 --> 00:05:37,788 different. But over the annual average, the latitude 72 00:05:37,788 --> 00:05:42,849 and the geometry that shows that, the geom, the best geometry is to have it 73 00:05:42,849 --> 00:05:46,732 tilted from the horizontal in the southerly direction. 74 00:05:46,732 --> 00:05:50,340 And, of course, the other limitation. You can't have any trees. 75 00:05:50,340 --> 00:05:54,852 Here in Atlanta, most of our residential areas were blessed with a lot of trees in 76 00:05:54,852 --> 00:05:57,312 one way. But then, you get a lot of shading. 77 00:05:57,312 --> 00:06:02,010 And, so, how, where you can use solar energy depends on the site, the location, 78 00:06:02,010 --> 00:06:04,762 and the orient, the orientation of the house. 79 00:06:04,762 --> 00:06:09,628 another way we utilize solar energy is what we call solar power tower. 80 00:06:09,628 --> 00:06:13,378 There's several ways. I'm just pointing out the two big ones 81 00:06:13,378 --> 00:06:17,818 that we'll talk about now that's expanding commercially and fairly 82 00:06:17,818 --> 00:06:20,822 rapidly. And in this case You've got thousands of 83 00:06:20,822 --> 00:06:24,942 mirrors that you see down there. This is made from an airplane looking 84 00:06:24,942 --> 00:06:29,047 down on this circle that's probably 1/4 to 1/2 a mile in diamater. 85 00:06:29,047 --> 00:06:33,752 So it's a large large installation and it produces electricity and of course the 86 00:06:33,752 --> 00:06:38,497 photovoltaic cell produces electricity. The sun shines directly on them and the 87 00:06:38,497 --> 00:06:43,883 solid state device has wires running to it, it produces electricity from that. 88 00:06:43,883 --> 00:06:47,637 in this case, the sun is reflected by these mirrors. 89 00:06:47,637 --> 00:06:52,576 That each 1 of these little dots are mirror's, on the surface of the earth. 90 00:06:52,576 --> 00:06:56,379 And they track, they have 2 access tracking we call them. 91 00:06:56,379 --> 00:06:59,614 You can orient them in any direction you want to. 92 00:06:59,614 --> 00:07:04,824 So a computer program makes those mir, mirrors track, so the sun light falling 93 00:07:04,824 --> 00:07:11,116 on their mirror, Is reflected off of that mirror on to the top of this tower. 94 00:07:11,116 --> 00:07:17,569 And on the top of this tower there's a boiler, a steam boiler, just like in a 95 00:07:17,569 --> 00:07:24,704 steam power plant fueled by coal there's, a boiler and a hot Fire oil sustained in 96 00:07:24,704 --> 00:07:29,690 this case all the sunlight that is reflected onto this boiler heats the 97 00:07:29,690 --> 00:07:33,678 boiler up to very high temperatures and boils the steam. 98 00:07:33,678 --> 00:07:39,317 So this is one that you've seen built and several of them being built right now as 99 00:07:39,317 --> 00:07:44,669 a matter of fact out in California in the Mojave desert and Arizona and those 100 00:07:44,669 --> 00:07:47,842 places. The first ones were built back in the 101 00:07:47,842 --> 00:07:51,171 80's. Technology has been around for a while. 102 00:07:51,171 --> 00:07:56,122 So for large scale solar, this is a pretty cost effective way to produce 103 00:07:56,122 --> 00:07:59,730 electric power. But again, it produces electric power 104 00:07:59,730 --> 00:08:02,704 from a conventional steam power plant cycle. 105 00:08:02,704 --> 00:08:07,978 But it's using The sun to heat up and boil the steam that's reflected from 106 00:08:07,978 --> 00:08:13,469 these thousands of mirrors rather than a fire that's burning fossil fuels. 107 00:08:13,469 --> 00:08:19,331 so, how much, how can we calculate how much energy strikes a solar collector 108 00:08:19,331 --> 00:08:25,054 surface? Well, as I mentioned, it varies, varies by day of the year because that's 109 00:08:25,054 --> 00:08:31,592 dependent on where the sun is in the sky. And but let's look at the annual average. 110 00:08:31,592 --> 00:08:35,755 Energy per day falling on a fixed collector tilted south. 111 00:08:35,755 --> 00:08:41,850 Now this includes weather situations cloudy days, rainy days, night of course. 112 00:08:41,850 --> 00:08:46,462 And so it's the average and it varies by geographical location. 113 00:08:46,462 --> 00:08:50,849 And it also varies by your solar collector orientation and your tracking 114 00:08:50,849 --> 00:08:54,440 mat, method. if you have Two Axis Tracking, where it's 115 00:08:54,440 --> 00:08:58,048 always looking directly at the sun, well, that's the best. 116 00:08:58,048 --> 00:09:02,920 if you have a Fixed Plate Tilted South At the Latitude, which we've just been 117 00:09:02,920 --> 00:09:08,152 discussing, that's another option, or you can, sometimes you may only have a Flat 118 00:09:08,152 --> 00:09:12,957 Horizontal surface or you want to put them on the side of a building, and it's 119 00:09:12,957 --> 00:09:18,277 only a vertical surface. [UNKNOWN] In our, energy building, the 120 00:09:18,277 --> 00:09:24,492 carbon neutral energy solutions building that we just built here at Georgia Tech, 121 00:09:24,492 --> 00:09:30,687 it has some constant, some photovoltaic collectors on the horizontal awning 122 00:09:30,687 --> 00:09:35,702 surface as well as on the vertical surface as well as on the roof tilted 123 00:09:35,702 --> 00:09:40,907 south so it's got collectors mounted on one new building with 3 different 124 00:09:40,907 --> 00:09:45,031 orientations. But, so, how much energy Solar energy 125 00:09:45,031 --> 00:09:52,362 falls on a square foot or a square meter on an average day throughout the year is, 126 00:09:52,362 --> 00:09:58,158 can be calculated, and it depends on where you are, in the U.S. 127 00:09:58,158 --> 00:10:05,366 You can see here, that, over here in Arizona and New Mexico, you get the, the 128 00:10:05,366 --> 00:10:08,912 maximum. Solar energy falling. 129 00:10:08,912 --> 00:10:18,152 And over in [INAUDIBLE] in Florida and in the northwest, you get less solar energy 130 00:10:18,152 --> 00:10:20,692 falling. And, 131 00:10:20,692 --> 00:10:23,932 So, that's a, Excuse me. 132 00:10:23,932 --> 00:10:25,742 yeah. And. 133 00:10:25,742 --> 00:10:32,677 There's a scale here, the maximum we get is about 7 kilowatt hours per day on 134 00:10:32,677 --> 00:10:39,427 average for the year, 7 kilowatt hours per year out here in, Arizona, 135 00:10:39,427 --> 00:10:45,682 California, New Mexico. and when you move to the lighter yellow 136 00:10:45,682 --> 00:10:49,075 areas Then it goes down to the minimum in the US. 137 00:10:49,075 --> 00:10:51,920 Like, up here in the north, you get about 4. 138 00:10:51,920 --> 00:10:56,615 So, there's almost a factor of 2 difference in the amount of solar energy 139 00:10:56,615 --> 00:11:01,191 falling on these collectors. depending on where you are in the US. 140 00:11:01,191 --> 00:11:06,180 And notice, it says at the top. This is, annual in the right, upper right 141 00:11:06,180 --> 00:11:08,997 hand corner. So that's the annual average. 142 00:11:08,997 --> 00:11:13,332 It's also the. Flat plate, tilted south at the latitude. 143 00:11:13,332 --> 00:11:19,364 So it's not tracking, it's fixed. But it's as majority of the collectors 144 00:11:19,364 --> 00:11:26,083 and the solar system installations are mounted in exactly this manner, tilted to 145 00:11:26,083 --> 00:11:33,538 the south at the latitude they're fixed. Well, how might we calculated. 146 00:11:33,538 --> 00:11:39,415 We can actually calculate this for your, your, or, your location. 147 00:11:39,415 --> 00:11:46,276 and by going to a US Department of Energy National Renewable Energy Laboratory 148 00:11:46,276 --> 00:11:50,286 called NREL. out in Golden, Colorado, and, it's a 149 00:11:50,286 --> 00:11:55,447 laboratory of the US Department of Energy, and they've got an interactive 150 00:11:55,447 --> 00:11:59,516 on-line map. So let's go to this, interactive on-line 151 00:11:59,516 --> 00:12:04,856 map The web address is as you see on the, on the, in the blue here. 152 00:12:04,856 --> 00:12:10,377 http it's a long, long one. Hopefully you can click on it and it will 153 00:12:10,377 --> 00:12:14,244 take you there. You can copy and paste it into your 154 00:12:14,244 --> 00:12:17,352 browser. So I have my browser up here. 155 00:12:17,352 --> 00:12:20,476 At that location, and this is the first page. 156 00:12:20,476 --> 00:12:23,038 U.S. Solar Radiation Resource Maps. 157 00:12:23,038 --> 00:12:28,416 So you probably want to stop your video and pull this page up at this point, and 158 00:12:28,416 --> 00:12:32,283 then come back. And we'll walk through how to use this to 159 00:12:32,283 --> 00:12:37,973 calculate, whatever situation and orientation and geographical location you 160 00:12:37,973 --> 00:12:40,322 might be. Be interested in. 161 00:12:40,322 --> 00:12:45,235 The first thing you can do is you can, select the data type. 162 00:12:45,235 --> 00:12:49,583 You can select average, which is noted there right now. 163 00:12:49,583 --> 00:12:55,740 You can, select the minimum or you can select the maximum, for the day. 164 00:12:55,740 --> 00:13:00,804 The maximum for the day or minimum for the day on, on the average. 165 00:13:00,804 --> 00:13:05,214 You can, you can look at the The, selected by the month. 166 00:13:05,214 --> 00:13:11,221 You can pick one month, January through December, or you can pick the annual 167 00:13:11,221 --> 00:13:14,967 average. You notice for this chart that I had up 168 00:13:14,967 --> 00:13:19,602 and the previous slide. I had selected, as I mentioned to you, 169 00:13:19,602 --> 00:13:25,062 the average, annual average, and I picked, and, and, and I wanted to see the 170 00:13:25,062 --> 00:13:29,332 annual and not the minimum or maximum for a particular day. 171 00:13:29,332 --> 00:13:35,290 and now you can select the orientations, they have a lot of orientations, more 172 00:13:35,290 --> 00:13:39,503 than I mentioned to you. you have single axis tracking 173 00:13:39,503 --> 00:13:43,292 concentrator. This is just tracking one axis rather 174 00:13:43,292 --> 00:13:48,322 than two axis, which of course is cheaper but is more, than two axis. 175 00:13:48,322 --> 00:13:53,983 More expensive than a fixed collector. And so, there, there's several Single 176 00:13:53,983 --> 00:14:00,385 Axis Tracking options here, and you got two Axis Tracking Flat Plate right here, 177 00:14:00,385 --> 00:14:05,917 that always will make the collector look at the sun, but of course, it's got to be 178 00:14:05,917 --> 00:14:10,860 mounted on a, on a tracking device. It's got electric motors that's 179 00:14:10,860 --> 00:14:16,138 controlled by computers, that always keeps it looking flat, straight at the 180 00:14:16,138 --> 00:14:20,123 sun. And, you can do the 1 that I, that most, 181 00:14:20,123 --> 00:14:25,763 most installations are using. A flat plate [INAUDIBLE] tilted south at 182 00:14:25,763 --> 00:14:29,890 the latitude. And that's the 1 that I had selected to 183 00:14:29,890 --> 00:14:33,611 generate the map that I just showed you before. 184 00:14:33,611 --> 00:14:37,962 you can pick the horizontal flat plate down here. 185 00:14:37,962 --> 00:14:42,868 Horizontal flat plate that if you've got a horizontal surface and that's all you 186 00:14:42,868 --> 00:14:47,577 got and it's the cheapest way to install them, then you could look and see the 187 00:14:47,577 --> 00:14:52,433 penalty for mounting them horizontally versus tilting them southern, south at 188 00:14:52,433 --> 00:14:56,548 the latitude angle. Of course, if the equator, the horizontal 189 00:14:56,548 --> 00:15:00,778 is also the optimum. you can look at the south facing vertical 190 00:15:00,778 --> 00:15:03,823 plate, flat plate, on the south facing wall. 191 00:15:03,823 --> 00:15:07,684 north south access tracking they got alot of options here. 192 00:15:07,684 --> 00:15:12,096 I won't bother to go through them. But if you look at the horizontal flat 193 00:15:12,096 --> 00:15:17,532 plate I'll pick something different. On this one, and the map that I showed 194 00:15:17,532 --> 00:15:24,107 you earlier, and you go down here then and you just make those three selections 195 00:15:24,107 --> 00:15:29,432 and click view map and now you, you get this map and you get a 196 00:15:29,432 --> 00:15:34,152 as you see there. And, you get the kill it down here, you 197 00:15:34,152 --> 00:15:40,049 get the kilowatt hours per day. It, it runs from 10 to 14 kWh/m^2/day. 198 00:15:40,049 --> 00:15:46,789 The color was none of this on there, all the way down to the darker blue, which is 199 00:15:46,789 --> 00:15:50,908 0 to 2. And of course, again, the Southwest, 200 00:15:50,908 --> 00:15:56,414 which is where you see a lot of installations is the best, and then as 201 00:15:56,414 --> 00:16:01,730 you move north in this situation, they, you're getting further away from the 202 00:16:01,730 --> 00:16:06,898 equator where the horizontal is optimum and you collect less and less energy or 203 00:16:06,898 --> 00:16:12,152 you, less of the, the solar energy strikes the surface So that's a, that's a 204 00:16:12,152 --> 00:16:17,933 nice interactive web site so you can look at your situation and look at any kind of 205 00:16:17,933 --> 00:16:22,337 tracking option or mounting option that you might be interested in. 206 00:16:22,337 --> 00:16:22,951 Thank you.