Muchachos Posted May 15, 2021 Share Posted May 15, 2021 A friend of mine installed his solar system a few months ago and he is not happy with his performance. He has 10x390W Panels( 2 string of 5) lying flat on his carport roof. The panels are connected to a victron MPPT 250/100 and he is using a MultiPlus 5KVa inverter. He has space for another 5 panels on a flat roof on the house and he can addd another 5 on other parts of the roof which is not flat? Can his system(inverter and MPPT) take another 10x390W panels to get him to charge his 4x4.8KWh batteries(Huawei ESM48100A1) ? The Victron MPPT calculator says is recommending same MPPT that is currently installed for the 4 strings. Should we consider putting on brackets on the flat roof to increase the angle of the panels and make them face NE? Will there be an issue mixing the 5 non-fat planels with the existing flat panels? Thanks in advance. Quote Link to comment Share on other sites More sharing options...
Dewald Brink Posted May 15, 2021 Share Posted May 15, 2021 HI Muchachos... I would start by putting brackets on the panels. That will increase the panel performance because of the angle and because the panels will be a bit cooler. ( I read somewhere that one should never have panels flat on a roof because the get too hot...) I had the same issue when I started with this stuff. I also have a victron installation with only 6X 275W panels and on some days I get up 1.7kw from the panels thats on cold days. If you add another 5 panels you should get about 5.8kw total power, that is the max the 250/100 controller can handle. hope this helps. Quote Link to comment Share on other sites More sharing options...
Muchachos Posted May 17, 2021 Author Share Posted May 17, 2021 Thanks Dewald, Will arrange to have the panels put on a bracket with a little bit of an angle. At this rate he is not able to get an angle between than 5 degrees without messing up the esthetics of the house. On 2021/05/15 at 5:13 PM, Dewald Brink said: If you add another 5 panels you should get about 5.8kw total power, that is the max the 250/100 controller can handle. What happens if he add more panels than the MPPT can handle? Trying to have more production during cloudy days so that the batteries can still charge. On 2021/05/15 at 5:13 PM, Dewald Brink said: I also have a victron installation with only 6X 275W panels and on some days I get up 1.7kw from the panels thats on cold days. The peak production on the system to date is around 2.3kw. Trying to get to around 3.5 - 4kw peak. Quote Link to comment Share on other sites More sharing options...
Muchachos Posted May 17, 2021 Author Share Posted May 17, 2021 3 minutes ago, Brani said: If you don't exceed 250V you will be fine. All that will happen is your current will be limited to the max spec of the MPPT. It's a recommended practice to oversize the panels in order to help on those cloudy days. Thanks Brani, what is the recommended over size? 120%? Quote Link to comment Share on other sites More sharing options...
Muchachos Posted May 17, 2021 Author Share Posted May 17, 2021 Thanks Quote Link to comment Share on other sites More sharing options...
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