June 10, 20224 yr 3 hours ago, P1000 said: No, it is correct if you use 180° Azimuth and don't have shading. It works on averages, and in the inner regions, there is a lot less cloud cover in winter months. You can add horizon data and it will also calculate for shadows. If I type Azimuth as 180 it inserts it as - 179 in the table and then the result shows better in winter passing even the best one can generate in Gauteng.
June 10, 20224 yr 12 minutes ago, Scorp007 said: If I type Azimuth as 180 it inserts it as - 179 in the table and then the result shows better in winter passing even the best one can generate in Gauteng. 👍
June 10, 20224 yr On 2022/06/08 at 7:51 PM, Scorp007 said: Not knowing what settings you have on the Axpert it might not be a problem with your panels. If they are idling with low load you only get 250W of which the inverter could be using 50W.200W goes towards battery charging. The moment you switch on a kettle or micro the panels produce a lot more. Thus the load is what is effecting the panel output. Is this load not taken from the battery and not from PV. As the battery provides power the panels produce a lot more. I lot of problems people experience comes down to the actual settings used and not always the inverter or panels. Even at the lower output these days my peak PV was 76% of the PV Watts of my system today. All PV is used and not correlated to battery state or load. I am fitting a HA02 battery balancer and a 100amp Battery Multi Function Tester and SOC indicator, this coming Sunday. Will be double checking everything and will note settings etc and post on Monday. Currently basic setting is based on recommended settings for AGM from TheSunPays : 01- SUB have tried SBU 02- 40amp 05- User 10- Auto or online and Eco at night 11- 10amp 12- 49v 13- 54v 26- 56.5v 27- 55v 29- 48v The microwave pulls generally around 1500-2000watts and kettle around 900watts and i have tested playing between the 2 and also have tried the oven with them aswell. i can have 2000wats load or 3000watts load and pv only ever goes up to around the 1300/1400w region and thats on a clear sunny day around 11am to 2pm. Will be checking panel tilt angle but cant see that being a issue. pic in post is my panels as per the Suns path app.
June 12, 20224 yr Been monitoring and testing from 10:30am - 2:30pm. Its beautiful clear sky day here in Durban. Tried different loads up to 3.5kw using different appliances. I am getting a max of 1.1/1.2kw pv input irrespective of what the load is. Have tried between different settings in 02 ans 16 but no difference. 8 x 480w panels in 2s4p config. 3800w potential. Current settings on the 5KV King. 01 SUB 02 40AM P05 USE 10 AUTO 11 10AMP 11 49V 13 54V 16 SLB UDC 23 BYE 26 56.4V 27 55.2V 29 48V 32 AUTO Edited June 12, 20224 yr by razzor13bt
June 13, 20224 yr actually have not tried with the mains switched off. will try it tomorrow. will get my daughter to check it at lunch time.
June 16, 20224 yr On 2022/06/10 at 12:12 PM, Scorp007 said: This seems to be a difficult calculator. If you use azimuth of 180 it shows you generate a lot more in winter than summer. If at 0deg then you get the following result. Winter values are totally out of line. Yeah, I noticed this two when I was doing some initial planning a month or so back. Then it dawned on me that it was a European calculator and they are in the northern hemisphere. Did you set the location? You really should show your inputs and not just your output like so:
June 16, 20224 yr 10 minutes ago, SmittySmit said: Yeah, I noticed this two when I was doing some initial planning a month or so back. Then it dawned on me that it was a European calculator and they are in the northern hemisphere. Did you set the location? You really should show your inputs and not just your output like so: I used the map to set my location. It picked up my co-ords. Still not sure why one needs to alter the azimuth which is the metric that causes you to get a higher yield in our winter time. When the azimuth is left as it is filled in after selecting on the map and the winter is lower the values of 80% lower than summer just seems out of line.
June 16, 20224 yr 3 minutes ago, Scorp007 said: I used the map to set my location. It picked up my co-ords. Still not sure why one needs to alter the azimuth which is the metric that causes you to get a higher yield in our winter time. When the azimuth is left as it is filled in after selecting on the map and the winter is lower the values of 80% lower than summer just seems out of line. Well good on getting your co-ordinates in there. I do not understand what you are trying to say as the azimuth of your roof makes a huge difference to how much sun the panels mounted to it will be able to produce. In our southern hemisphere north FACING panels will help optimise the amount of light falling on the panels. Especially in winter when the sun appears to be further north compared to summer when it is more directly overhead. Ja but please post a screenshot showing the settings that you used. There are multiple factors, e.g., roof slope, that will make a huge difference to the production figures.
June 17, 20224 yr 9 hours ago, SmittySmit said: Yeah, I noticed this two when I was doing some initial planning a month or so back. Then it dawned on me that it was a European calculator and they are in the northern hemisphere. Did you set the location? You really should show your inputs and not just your output like so: That graph looks correct to me - you will get the same with helioscope. Your slope is more than your ~25° latitude, so it will favour winter months. That said, in most residential installations, the longer shadows in winter might affect the output.
June 17, 20224 yr I went through whatever i could think off yesterday. around 10:30am i got a max pv input of 1.33kw with a load of 2.3kw and this was checked with and with out mains connected. probably a difference of a 100-200w difference with mains off. By 12:30 i was getting 1.2kw. In the time inbetween i had washed the solar panels that where a little dusty but it made no noticeable difference. i then disconnected each pv string and measured a open voltage of 84v and a deviation of +-0.2v between the highest and lowest string. with the panel VOC stating it should be 50.3v per panels i was expecting around a 100v. so there is a descrepency of +-16v lower VOC. wiring from the panels to the combiner box is 3-4 meters. It was my wifes birthday so had to stop there to have a braai. Will be looking into some more over the weekend. Edited June 17, 20224 yr by razzor13bt
June 17, 20224 yr 6 minutes ago, razzor13bt said: with the panel VOC stating it should be 50.3v per panels i was expecting around a 100v. so there is a descrepency of +-16v lower VOC. The Voc you are looking for will only be under the same conditions as the test was performed. With the panel at 25°C and 1000W/m².
June 17, 20224 yr 12 hours ago, SmittySmit said: Well good on getting your co-ordinates in there. I do not understand what you are trying to say as the azimuth of your roof makes a huge difference to how much sun the panels mounted to it will be able to produce. In our southern hemisphere north FACING panels will help optimise the amount of light falling on the panels. Especially in winter when the sun appears to be further north compared to summer when it is more directly overhead. Ja but please post a screenshot showing the settings that you used. There are multiple factors, e.g., roof slope, that will make a huge difference to the production figures. All OK and nothing further to add. These results you posted 13hrs ago showing the highest yield of the year is in July in Gauteng does not correlate with my actual yields over a few years. It also seems quite a number of members get a lower yield in winter.
June 17, 20224 yr 13 hours ago, SmittySmit said: Well good on getting your co-ordinates in there. I do not understand what you are trying to say as the azimuth of your roof makes a huge difference to how much sun the panels mounted to it will be able to produce. In our southern hemisphere north FACING panels will help optimise the amount of light falling on the panels. Especially in winter when the sun appears to be further north compared to summer when it is more directly overhead. Ja but please post a screenshot showing the settings that you used. There are multiple factors, e.g., roof slope, that will make a huge difference to the production figures. Double post deleted. Edited June 17, 20224 yr by Scorp007 Double post
June 17, 20224 yr 3 hours ago, P1000 said: The Voc you are looking for will only be under the same conditions as the test was performed. With the panel at 25°C and 1000W/m². Correct and noted.
June 18, 20224 yr On 2022/06/17 at 12:06 PM, Scorp007 said: All OK and nothing further to add. These results you posted 13hrs ago showing the highest yield of the year is in July in Gauteng does not correlate with my actual yields over a few years. It also seems quite a number of members get a lower yield in winter. Heh, so what angle are you panels at? The steeper (i.e., more vertical less horizontal) the angle when they pointed north, the more they'll produce in winter at the expense of reduced production in summer. While you are at it include the azimuth (hopefully it is rather close to north and failing that, north-north-east or north-nort-west). My entire point is that they are multiple variables involved here. Unless we state all the variables then we can not compare results or estimates.
June 18, 20224 yr 2 hours ago, SmittySmit said: Heh, so what angle are you panels at? The steeper (i.e., more vertical less horizontal) the angle when they pointed north, the more they'll produce in winter at the expense of reduced production in summer. While you are at it include the azimuth (hopefully it is rather close to north and failing that, north-north-east or north-nort-west). My entire point is that they are multiple variables involved here. Unless we state all the variables then we can not compare results or estimates. It would be interesting to know what angle you would use to get the high yields you expect in June or July as per previous posts. If one just had to think for a moment and forget the debate. How would you yield more in Gauteng in winter when you have 4 hours less sun. This from a reply by NigelL some time ago.
June 19, 20224 yr 13 hours ago, Scorp007 said: It would be interesting to know what angle you would use to get the high yields you expect in June or July as per previous posts. If one just had to think for a moment and forget the debate. How would you yield more in Gauteng in winter when you have 4 hours less sun. This from a reply by NigelL some time ago. You have to account for average insolation. Basically - in summer in Gauteng, you have on average a lot more cloudy/rainy days, this brings the average down. A proper estimation uses historic insolation data and augments the calculation in your graph with that.
June 28, 20224 yr On 2022/06/18 at 7:07 PM, Scorp007 said: It would be interesting to know what angle you would use to get the high yields you expect in June or July as per previous posts. If one just had to think for a moment and forget the debate. How would you yield more in Gauteng in winter when you have 4 hours less sun. This from a reply by NigelL some time ago. In the screenshot that I posted earlier I used a slope of 34 degrees with North facing (check the azimuth) panels. If that was changed to say 24 degrees then it would favour summer production at the expense of winter. The reason for this is that sun is further south in summer (more directly overhead) and further north in winter (lower on the horizon). With north facing panels, the steeper the slope, the more they are pointing north and the shallower the slope the less they are pointing North. Cloud cover and day length are also factors but I prefer isolate one variable at a time to understand its affect on the outcome. Then add up all the affects and we get the total outcome.
June 28, 20224 yr Im still stumped as to why at mid morning to mid day with a clear sky, the 8 x 480w panels can not generate at least 50% of its rated power. On Sunday i fiddled some more and under various loads it will not make more than 1250-1300w (+-24amps) I tried disconnecting 1 string at a time of the 4 strings and power would drop a similar amount. +-300-340w. Borrowing 4 panels this weekend from a friend to test.
June 28, 20224 yr 1 hour ago, razzor13bt said: Im still stumped as to why at mid morning to mid day with a clear sky, the 8 x 480w panels can not generate at least 50% of its rated power. On Sunday i fiddled some more and under various loads it will not make more than 1250-1300w (+-24amps) I tried disconnecting 1 string at a time of the 4 strings and power would drop a similar amount. +-300-340w. Borrowing 4 panels this weekend from a friend to test. What brand panels are those?
June 29, 20224 yr Not to sure on brand. This is the sticker on the rear of the panel. I actually bought these from a relative in December. He bought 2 pallets of panels at the time from a supplier in JHB. Edited June 29, 20224 yr by razzor13bt
June 29, 20224 yr According to the specs of those panels, they have to be 24.9% efficient. Anything from an unknown brand that is more than 21% is suspect. More than 23% is pretty much a guarantee that it won't do what's on the label.
June 29, 20224 yr Ok. Will look into that. Will see if my relative is having issues with there setup.
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