1 00:00:07,080 --> 00:00:07,860 Hi everyone. 2 00:00:08,130 --> 00:00:12,250 Welcome back to BP Solar energy course. 3 00:00:12,260 --> 00:00:14,050 Today is his thrall. 4 00:00:14,370 --> 00:00:25,130 I would like to discuss with you say effect of a parameter of great importance which is the team preacher. 5 00:00:25,320 --> 00:00:34,840 First I would like to answer the standard question which is a greater team preacher better for the B 6 00:00:34,850 --> 00:00:44,290 the output or is the V output independent of temperature changes in this graph. 7 00:00:44,390 --> 00:00:55,310 You see Z Ivy curve of the V module at a given her audience as a temperature as shown intellect curve 8 00:00:56,200 --> 00:01:01,740 is in miniature increase away the radius is constant. 9 00:01:02,550 --> 00:01:15,810 We see only curve Z and not like the right to so we see is that why is a cut up has very increased. 10 00:01:16,190 --> 00:01:27,170 There is a significant drop in voltage this mean that it over all power has been decreased. 11 00:01:27,170 --> 00:01:33,030 On the other hand is that in preacher with two degrees. 12 00:01:33,170 --> 00:01:45,260 With respect to original condition a Y and Z radius were a cornerstone ZBB output would show an increase 13 00:01:46,220 --> 00:01:49,910 the minute increase in current wisdom. 14 00:01:49,950 --> 00:02:00,530 Richer can be explained with the fact that current concentration and mobility increase is the semiconductor 15 00:02:00,530 --> 00:02:01,510 wisdom bridge. 16 00:02:01,970 --> 00:02:14,090 This is consistent with our basic understanding that semiconductor unlike regular conductor except better 17 00:02:14,090 --> 00:02:23,390 conductivity with increasing compression and is a perfect isolated and absolute temperature of zero 18 00:02:23,390 --> 00:02:33,590 code is indeed pleasing effect on voltage can be explained from this four of the basic diet equation 19 00:02:34,100 --> 00:02:36,740 which have been seen Ellen 20 00:02:41,120 --> 00:02:54,850 the open circuit is equal to in times hold this man constant times in pressure over a charge of electron 21 00:02:55,690 --> 00:03:08,660 times Len both to tide over saturated current or like a second lost one or was it in breach of affects 22 00:03:08,690 --> 00:03:19,540 and various term in this equation the net effect of the preacher is that it decrease that open circuit 23 00:03:19,540 --> 00:03:27,940 voltage linearly the drop in open circuit voltage wisdom pressure is mainly referred to the increase 24 00:03:28,060 --> 00:03:36,380 in the linkage linkage Carter or Ford to die which is all in the dog wisdom preacher 25 00:03:39,190 --> 00:03:50,630 because I would strongly depend on to Richard the magnitude of reduction varies inversely with open 26 00:03:50,630 --> 00:03:51,930 circuit voltage. 27 00:03:52,160 --> 00:04:02,240 This mean zat cells with higher open circuit voltage are less affected pointing preachers and cells 28 00:04:02,270 --> 00:04:13,370 with lower open circuit voltage this mean zap saw certain based on syllable with of certain voltage 29 00:04:13,670 --> 00:04:25,650 of all points six five fold will it be more affected Zen a silicone with open circuit voltage off all 30 00:04:25,650 --> 00:04:28,400 point is five fold. 31 00:04:29,190 --> 00:04:40,070 So now you have an idea of effective in breach of UN be the outcome but how do we qualify as this effect 32 00:04:42,140 --> 00:04:49,180 is it in breach of module we have to increase by 10 degrees Celsius. 33 00:04:49,380 --> 00:04:55,510 How would that all of the Be Affected Web. 34 00:04:55,670 --> 00:05:06,320 First of all the beating module manufacturer include what is known as temperature coefficient in that 35 00:05:06,320 --> 00:05:15,010 the sheet of Z commercial modules in breach of coefficient which is the X by DTA is. 36 00:05:15,270 --> 00:05:26,320 But a rate of change of parameter X with in for a second to appreciate coefficient the voltage is the 37 00:05:26,320 --> 00:05:37,540 rate of change of the voltage wisdom breach similarly set in breach of coefficient of power is the rate 38 00:05:37,540 --> 00:05:49,140 of change of out the bar with immigration a difficult date the shift of conversion BD module specifies 39 00:05:49,210 --> 00:06:01,260 that preacher coefficient force the pole for certain voltage and short circuit current under EDC condition 40 00:06:03,370 --> 00:06:05,760 as shown is the left to figure 41 00:06:09,300 --> 00:06:19,500 given this coefficient how do we calculate the b v output with respect to temperature change we can 42 00:06:19,500 --> 00:06:33,380 use this simple equation which is x of T is equal to x at the standard condition allows us to reach 43 00:06:33,380 --> 00:06:34,980 a coefficient. 44 00:06:35,340 --> 00:06:37,620 Times Z. 45 00:06:37,710 --> 00:06:42,980 Ambient temperature minus is standard to. 46 00:06:45,110 --> 00:06:51,400 X maybe so all the circuit voltage or short circuit column or evens the pole. 47 00:06:53,190 --> 00:07:00,170 Z Turner D S by D d do needs to reach your coefficient. 48 00:07:00,310 --> 00:07:02,660 Also particle parameters. 49 00:07:03,890 --> 00:07:16,190 Z reference temperature taken for this calculation is that is DC temperature which is twenty five degrees 50 00:07:16,200 --> 00:07:16,840 ladies 51 00:07:19,850 --> 00:07:31,240 let's take a look at an example is the maximum power output of a dean will go under is the seed is to 52 00:07:31,240 --> 00:07:32,620 one hundred and fifty. 53 00:07:32,620 --> 00:07:39,940 What is the temperature coefficient of both is negative to what they are. 54 00:07:39,940 --> 00:07:43,590 Degrees loses then Zen module. 55 00:07:43,690 --> 00:07:55,390 Power output of often creatures 30 degree can be calculated as full to 150 what loss. 56 00:07:55,770 --> 00:08:08,130 Minus two times serve T minus 25 well again zap out the board equal to two hundred and forty. 57 00:08:08,170 --> 00:08:09,020 What. 58 00:08:10,910 --> 00:08:20,030 As you can see a sign of the temperature or fiction that your mind as a parameter is increasing or decreasing 59 00:08:20,080 --> 00:08:20,930 with compression. 60 00:08:21,710 --> 00:08:29,410 Now we must be careful while making this calculation it is a previous example. 61 00:08:30,850 --> 00:08:41,110 When he said that preacher will certainly decrease laces it will mean that B V modules temperature or 62 00:08:41,230 --> 00:08:45,490 the NBN to bridge or should that to be the same. 63 00:08:45,910 --> 00:08:56,530 As it turns out the module temperature or the silting preacher Zeb pool or turn NZ literature can d 64 00:08:56,800 --> 00:08:59,730 y difference from the ambient temperature. 65 00:09:00,430 --> 00:09:01,000 Let's see. 66 00:09:01,030 --> 00:09:06,000 Why should be a difference between some wonderful temperature and ambient temperature. 67 00:09:09,050 --> 00:09:18,820 Zepp could be several factor impacting the heat flow in and out of the modules encapsulation of solar 68 00:09:18,820 --> 00:09:25,290 or Sun is the measure of factor increasing of the operating temperature of the easy money. 69 00:09:27,320 --> 00:09:35,750 The eventual operating temperature of the module will be a result of this certain equilibrium between 70 00:09:35,750 --> 00:09:45,560 heat generated by the module and the heat loss to surrounding environment the heat exchange with the 71 00:09:45,560 --> 00:09:56,570 environment in turn could depend so on several factors like ambient temperature wind speed heat transfer 72 00:09:56,570 --> 00:10:00,760 coefficient between the module and the environment. 73 00:10:03,040 --> 00:10:09,960 And certainly conductivity of the modules as well Zen. 74 00:10:10,240 --> 00:10:15,190 How do we estimate Z module temperature. 75 00:10:15,430 --> 00:10:18,030 Based on the ambient temperature. 76 00:10:18,220 --> 00:10:23,980 If we have to dig it down for so many factors 77 00:10:26,910 --> 00:10:32,540 fortunately there is a model provided in literature. 78 00:10:32,540 --> 00:10:43,070 Z get responsible is to meet Z module temperature as a function of the M.B.A. Bridge as the self temperature 79 00:10:43,070 --> 00:10:56,030 is equal to ambient temperature boss error ideation times coefficient cold in 0 C D minus twenty over 80 00:10:56,180 --> 00:10:57,800 eight hundred. 81 00:10:57,810 --> 00:11:09,720 This model is sometimes called the N O C D model due to the use of knowing and operating seldom preacher 82 00:11:09,930 --> 00:11:23,300 or in the city of said b the same or muddy means the end OCD OCD in this equation is the nominal operating 83 00:11:24,010 --> 00:11:35,490 self to preach in the home city is the team preacher attend boys MTV sail under and there are gradients 84 00:11:37,100 --> 00:11:49,170 of 800 watt been Mitre Square with a nominal wind speed of one meter per second 85 00:11:52,660 --> 00:12:04,450 and is the ambient temperature is equal to to any degrees loses few G is the province as in instance 86 00:12:05,470 --> 00:12:17,390 with the ambient temperature is that CMB Zumwalt who gives a corresponding symptom preacher SDL as can 87 00:12:17,390 --> 00:12:25,100 be seen from this equation the certain preacher isn't the only function of the ambient temperature but 88 00:12:25,190 --> 00:12:29,620 also as a function of radians. 89 00:12:29,990 --> 00:12:39,290 This makes things more interesting because if we consider that it radians as it's in breach or change 90 00:12:39,650 --> 00:12:50,060 over the Clinton years we would see effect of both the radius and temperature across this is in this 91 00:12:50,060 --> 00:13:01,730 graph which has been made using the actual ambient temperature and radians data as seen in Zen these 92 00:13:01,730 --> 00:13:15,050 are land in Z year off 2012 that corals funding certain creature have been calculated using the N O 93 00:13:15,050 --> 00:13:16,350 C T Model. 94 00:13:16,550 --> 00:13:24,810 This graph out of line the main reference from the N O C T model. 95 00:13:24,980 --> 00:13:35,660 Now you are aware of Z sifting preacher and the difference between it and the ambient temperature and 96 00:13:35,660 --> 00:13:44,060 you know said that ambient temperature is the air temperature but this is seldom pretty shook is the 97 00:13:44,060 --> 00:13:57,350 module to breach so see you in the next section where we are going to discuss that diet or b system 98 00:13:57,900 --> 00:14:08,430 wizardry it's great connected or stand alone we ve system so see you in the next step block.