Triassic Posted August 31, 2018 Author Share Posted August 31, 2018 On 26/08/2018 at 09:33, Nickfromwales said: single panel optimisation My frame comes in eight weeks and I’m now playing catch up! Could someone explain what is single panel optimisation? Link to comment Share on other sites More sharing options...
Triassic Posted August 31, 2018 Author Share Posted August 31, 2018 On 24/08/2018 at 10:03, Alexphd1 said: We looped cable from every panel into the loft space with a connection. This will allow easier maintance and repair down the line, I have not seen anybody else do this. I don’t have a loft space under the panels as it’s a cathedral ceilings. I’m thinking that the best place for the inverters is next to the main electrical fuse board, however this is in the basement and a long way from the panels. Is there any limit on the length of cables from the panels to the inverters? Link to comment Share on other sites More sharing options...
Alexphd1 Posted August 31, 2018 Share Posted August 31, 2018 Are you planning 1 inverter or multiple micro inverters? Link to comment Share on other sites More sharing options...
Ed Davies Posted August 31, 2018 Share Posted August 31, 2018 1 hour ago, Triassic said: Could someone explain what is single panel optimisation? Where you have a box of electronics for each panel to do at least part of the job of the inverter so you get a separate maximum-power-point tracker for each panel. Very useful if the panels are likely to get different amounts of sunshine, e.g, because the array is spread over bits of roof with different orientations or slopes or if there's shading that moves across the array during the day. Sometimes the box has a complete inverter and the output is mains AC. Usually then there's a separate box which co-ordinates them all (e.g., doing the anti-islanding stuff and data display). Or each box can just produce an intermediate output voltage with a separate box doing the conversion to mains voltage. Link to comment Share on other sites More sharing options...
Triassic Posted August 31, 2018 Author Share Posted August 31, 2018 1 hour ago, Alexphd1 said: Are you planning 1 inverter or multiple micro inverters? I'm having two sets of panels, one set south facing and the other east facing, so probably two inverters. The cable length from the panels to the inverters is around 15 metres. 1 hour ago, Ed Davies said: Where you have a box of electronics for each panel to do at least part of the job of the inverter so you get a separate maximum-power-point tracker for each panel. Very useful if the panels are likely to get different amounts of sunshine Luckily the panels will be in full sun, no shadows! Link to comment Share on other sites More sharing options...
Alexphd1 Posted August 31, 2018 Share Posted August 31, 2018 Most inverters (i think 3kw and up) have two strings so easily to split into east west. 15m is no problem but maybe go up to 6mm (from 4mm) cable this helps with voltage drop on longer runs(So my installer said). 1 Link to comment Share on other sites More sharing options...
Triassic Posted August 31, 2018 Author Share Posted August 31, 2018 7 hours ago, Triassic said: Luckily the panels will be in full sun, no shadows! Having made the above bold statement it got me thinking and looking. I’d been thinking along the lines of shadow from the house, chimneys and dormers and such like. Having been in the garden all day I’ve checked and there will shadows from a number of trees, not my trees I hasten to add! So what affect will shadows have on output? Is it even worth fitting panels knowing they will be in dappled sunlight for part of the day? Link to comment Share on other sites More sharing options...
ProDave Posted August 31, 2018 Share Posted August 31, 2018 I have trees. Lots of trees and they are my trees. I will be ground mounting mine, to the south of the tree line to avoid the shading issue. Link to comment Share on other sites More sharing options...
Triassic Posted August 31, 2018 Author Share Posted August 31, 2018 Unfortunately I don’t have a tree free aspect for a ground mount array. I’d got into my head that the roof would be above the tree, but having spent the day observing shadows, I’m not so sure. Maybe I’ll have to wait until the house is up and make further observations of shadows then. Link to comment Share on other sites More sharing options...
pdf27 Posted August 31, 2018 Share Posted August 31, 2018 Sounds like a good case for micro-inverters: they're a lot less affected by partial shade, AIUI the output goes from all panels being affected by the shade to only those actually in shade being affected by it. The other obvious point is how does the shaded portion of the day compare to when you would be likely to be using the electricity? Link to comment Share on other sites More sharing options...
Alexphd1 Posted August 31, 2018 Share Posted August 31, 2018 My panels are pretty bad shadowed by tress...... I bought a chainsaw? 1 Link to comment Share on other sites More sharing options...
ragg987 Posted August 31, 2018 Share Posted August 31, 2018 1 hour ago, Triassic said: Is it even worth fitting panels knowing they will be in dappled sunlight for part of the day? Panels require light, either direct or indirect. A light but of dappling for a few hours will likely have minimal impact. Also, if trees go bare in winter the impact will be less. So not as clear cut, but if shading at any point covers 10% of panels then output might only decrease 5% or less. Microinverters will help. Your other question about length of cables. One company tried to tell me the inverter had to be close to the panels else losses would be high. I used one of the online models to show that the cable length on DC side has low losses, or DC cable is perhaps 50m and AC is 2m. Works well, we got 4GWh in our first full year from a 4kWp install. Just bear in mind the amount of cable in a drum, it might be better to avoid joints to reduce potential points of failure. Link to comment Share on other sites More sharing options...
Triassic Posted August 31, 2018 Author Share Posted August 31, 2018 I spotted this in the news The European Union will end restrictions on the sale of solar panels from China early next week, a move EU producers said would lead to a flood of dumped products. Maybe panels will get even cheaper? Link to comment Share on other sites More sharing options...
Barney12 Posted September 1, 2018 Share Posted September 1, 2018 On 26/08/2018 at 09:33, Nickfromwales said: IIRC where @Barney12 got all his self-fit kit. Sorry for late reply. Yes, that’s where I got mine. Very good customer service. 1 Link to comment Share on other sites More sharing options...
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