Alex C Posted January 18, 2019 Share Posted January 18, 2019 23 minutes ago, jack said: Wowsers, we only managed 11.9kWh and we have 8.5kW! Shows you what a difference angle and orientation makes on a sunny winter's day. We're stuck with a relatively flat array, much of which is east west. I also need to get up on the roof and clean mine! We had just over 18kwh from a 5.5 kw system string inverter yesterday. we are only 5 degrees off due south and panels are at about 40 degrees. Link to comment Share on other sites More sharing options...
jack Posted January 18, 2019 Share Posted January 18, 2019 2 minutes ago, Alex C said: We had just over 18kwh from a 5.5 kw system string inverter yesterday. we are only 5 degrees off due south and panels are at about 40 degrees. You're making me feel inadequate now! Link to comment Share on other sites More sharing options...
Alex C Posted January 18, 2019 Share Posted January 18, 2019 Just now, jack said: You're making me feel inadequate now! Get on your roof with a bucket and sponge and give those panels a wash. We are very lucky in that there is no shading whatsoever on our roof. Link to comment Share on other sites More sharing options...
jack Posted January 18, 2019 Share Posted January 18, 2019 4 minutes ago, Alex C said: Get on your roof with a bucket and sponge and give those panels a wash. It's on the (very, very long) list of things to do. The list I should be working through right now rather than posting on BH. 5 minutes ago, Alex C said: We are very lucky in that there is no shading whatsoever on our roof. Unfortunately, we do have some shading from a large tree to the west south west of our house. Microinverters help, but when there's shade, there's shade. Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 18, 2019 Author Share Posted January 18, 2019 14 minutes ago, jack said: An interesting thing about PV, especially if you're using a standard inverter rather than micro-inverters or similar, is that the worst-performing panel limits the power that can be generated by all the rest on the same string. That means that if even one panel is shaded or dirty, it drags down the amount the rest of the panels can generate, often by a surprising amount. Even shading a couple of cells on a panel can be enough to make a difference: [Edited to add:] https://blog.aurorasolar.com/shading-losses-for-pv-systems-and-techniques-to-mitigate-them/. Cleaning may therefore be worth it, especially if you have any panels that have algae or dust on them (even if only in a corner or along the bottom). I'll likely consider it then. We also have our terrestrial aerial directly over 1 of the panels, and the birds like to sit on it and do what birds do, so 1 panel on the east side is always worse than the rest. Going to get an offset pole to mount the aerial away from the panels which I will do before they get a spring clean, might be a worthwhile investment even if its just as a one off, and i'll see how much difference it makes, they've had nothing done since install september 2015. Link to comment Share on other sites More sharing options...
Bitpipe Posted January 18, 2019 Share Posted January 18, 2019 1 minute ago, jack said: It's on the (very, very long) list of things to do. The list I should be working through right now rather than posting on BH. Mine too, however was just tallying up fuel costs for another thread and saw that our generation uncreased this year so they can't be that dirty... Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 18, 2019 Author Share Posted January 18, 2019 1 minute ago, Bitpipe said: Mine too, however was just tallying up fuel costs for another thread and saw that our generation uncreased this year so they can't be that dirty... Yeah we had a record breaker last year too, which initially made me think the dirt perhaps didn't make any difference (which is what several posts on the internet state) Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 18, 2019 Author Share Posted January 18, 2019 So much for upgrading the firmware, it doesn't like SDHC cards! ? One other thing which has cropped up recently was something i'd planned to do from the start, and that was to move half of the panels to a south facing roof which we didn't have at the time of install but we do now. I got in touch with a Solar PV company who are local and they said they can do it, but we would have to re-apply for FIT, which is obviously a big no no, does anyone here know any different? Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 18, 2019 Author Share Posted January 18, 2019 I've been monitoring the PV array today, albeit on a pretty dull day, and have noticed that the Power from A and B are always almost identical. When i was up in the loft with the front off of the inverter, I checked that A goes to one side and B goes to the other and everything checked out, but I can't really think of another reason why the power levels would be the same. I'm going to keep an eye on it again next week and see if its ever much different, for example when the sun is on one side and not the other. Link to comment Share on other sites More sharing options...
ProDave Posted January 18, 2019 Share Posted January 18, 2019 3 minutes ago, MikeGrahamT21 said: I got in touch with a Solar PV company who are local and they said they can do it, but we would have to re-apply for FIT, which is obviously a big no no, does anyone here know any different? Just get a non MCS electrician to move them and say nothing, Your output will go up a bit, if the FIT provider queries it, you have cut down a tree and reduced the shading you were previously getting 1 Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 18, 2019 Author Share Posted January 18, 2019 (edited) Its a bit risky though, we would stand to lose around £8000 if it got found out. We did have a guy come to the house a year or so ago to read the meter, and wouldn't they be able to look on google maps to see the different locations? The whole issue has actually stopped us from installing a dormer extension on our bungalow, which we weren't very happy about. Apparently, you can ask, but they are very black and white about it. Edited January 18, 2019 by MikeGrahamT21 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted January 18, 2019 Share Posted January 18, 2019 I'm pretty sure that all that is on the MCS chit is the number of panels, the make of the panels and the rated output. I don't think there's anything in there about orientation, so suspect that they wouldn't be able to prove for sure that you'd changed anything. You're allowed to replace damaged panels or an inverter without needing a new FIT application. I doubt very much that the meter reader that comes around would be the slightest bit bothered. Half the time our chaps been around to read the generation meter it's been dark, so he'd never get a look at the panels anyway. If you're worried about the meter reader spotting the change, you could always apply to change your FIT supplier to another company, at the same time as you shift the panels. Chances are you may get a different meter reader who'd be none the wiser as to what the original installation looked like. Link to comment Share on other sites More sharing options...
billt Posted January 18, 2019 Share Posted January 18, 2019 50 minutes ago, MikeGrahamT21 said: I've been monitoring the PV array today, albeit on a pretty dull day, and have noticed that the Power from A and B are always almost identical. When i was up in the loft with the front off of the inverter, I checked that A goes to one side and B goes to the other and everything checked out, but I can't really think of another reason why the power levels would be the same. That's to be expected on a cloudy day. The light is very diffuse so the power falling on the panels will be pretty much the same regardless of the direction they face. The meter reader is a meter reader, he will only be interested in the meter reading and I can't imagine that he will know anything about your installation apart from the address (and sometimes they can't even find that!) Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 18, 2019 Author Share Posted January 18, 2019 5 minutes ago, JSHarris said: I'm pretty sure that all that is on the MCS chit is the number of panels, the make of the panels and the rated output. I don't think there's anything in there about orientation, so suspect that they wouldn't be able to prove for sure that you'd changed anything. You're allowed to replace damaged panels or an inverter without needing a new FIT application. I doubt very much that the meter reader that comes around would be the slightest bit bothered. Half the time our chaps been around to read the generation meter it's been dark, so he'd never get a look at the panels anyway. If you're worried about the meter reader spotting the change, you could always apply to change your FIT supplier to another company, at the same time as you shift the panels. Chances are you may get a different meter reader who'd be none the wiser as to what the original installation looked like. Oddly the guy who came was from E.On and we are with British Gas for the FIT payments, so no idea how that works. You're right, there is no data regarding orientation on the sheet, but the company i contacted said straight away, you can't do it, and i can't see why they wouldn't have wanted to, as its free money for them. Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 19, 2019 Author Share Posted January 19, 2019 Since I darent move them, I’ve nothing to lose asking British gas for special permission and see what they say, at least that way we can’t be in the wrong. will monitor pv next week and get those figures which were asked for Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 21, 2019 Author Share Posted January 21, 2019 (edited) This was when the sun came out at 11.30 today: Edited January 21, 2019 by MikeGrahamT21 Link to comment Share on other sites More sharing options...
Ed Davies Posted January 21, 2019 Share Posted January 21, 2019 What's the Current[1]/[A], etc, about? The current in and out on each string so the difference is leakage between the strings or from the string to ground? Residual current shown at the bottom? But they're a lot more different in the second set of readings. Otherwise, to my naïve eyes it all looks quite reasonable. Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 21, 2019 Author Share Posted January 21, 2019 Yeah I can't figure out what Current 1 and A are, as they are almost the same, just slightly different, unless its Current (DC) and Current (AC) i.e. showing the inverter losses. I've disabled the Optitrac Global Peak functionality, as we have absolutely no shading what-so-ever, and according to internet sources this can reduce performance by as much as 2%, might not sound like much but thats around 70kwh over the year, which is a lot when its a simple setting. Still not had a reply back from SMA yet about SD card type, though I suspect its 1st gen SD, once I get one of those i'll do the firmware upgrade on the unit and see whats better about it, wish they would include release notes, they used to do Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 23, 2019 Author Share Posted January 23, 2019 So this has been the first day with full sunshine from morning til night, Ive kept the global optitrac switched off since Monday. Looking at the chart we lose a little first thing and last thing, but everything in between is better. Last time we had nearly as good generation was Jan 2017, but the temperature was higher that day, we did 5.0kwh, today just done a 5.12kwh which is the highest january amount we've ever recorded. So I don't think we are going to see huge increases, but for us this value should have always been set to off, and even with 2 more years under their belts the panels have put out more today than they've ever done in the month of january. I've also noted the power curve is different with optitrac turned off, its smoother. This is todays with it off. You can also see the drop off morning and night. This is before I switched it off, the curve is a lot less smooth, but doesn't drop off quite as sharp first and last thing. Ultimately, its a shame optitrac can't be scheduled to switch on at certain times of the day, as first and last thing would gain us a tiny bit more, but overall, i think off is best for us, and i'll continue to monitor as the months progress. It is almost impossible to directly compare, since no 2 days are the same Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted February 14, 2019 Author Share Posted February 14, 2019 So after messing around with the optitrac parameters, I can see we get a tiny bit less on a morning, though generation begins earlier, but the afternoon is much better, and longer, with middle of the day roughly the same as before, overall, we are generating more now than ever before. I've compared our solar array with others in the area (as local as were published on sunny places), and found that we trail behind massively. Looking on google maps, the yellow line is almost perfect south facing, and the red is pretty much south, slightly west, where as we are east west split, so I can agree there will be a difference, but this much?!?! We are of course in green: Link to comment Share on other sites More sharing options...
A_L Posted February 14, 2019 Share Posted February 14, 2019 @MikeGrahamT21PVGIS for Leeds in February gives about 30kWh/month for 1kWp on East and West 35° slopes and 50kWh/month for South 35° slopes. So I do not think anything is seriously wrong. I would expect the outperformance to be proportionately higher on sunny days and less on cloudy ones. Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted February 15, 2019 Author Share Posted February 15, 2019 Absolutely, but the systems shown above, even though they are south facing, are performing twice as good as ours in some cases. The PVGIS would be about right i'd say, we did 125kwh last February with a 4kwp system. The yellow bar person got nearly 200kwh last feb, so that also fits the bill. Just seemed a bit shocking yesterday just how much difference there was. Ah well, at least we are in the right bracket for performance, i'll stop worrying about it now and move onto something else lol Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted February 20, 2019 Author Share Posted February 20, 2019 So a while back I decided to send an email to British Gas FIT team to ask about the re-positioning of the panels, thinking they would come back saying no, to my amazement they rung yesterday and said as long as the panels aren't changing size or power output, and the system still goes through the same single MPAN, then we can re-position, and they sent it me on an email in writing. So good news on a few parts, this means we can go with the 6 panels south, and 2 extra east, and more importantly, we have the west side roof now free for a dormer extension!! Link to comment Share on other sites More sharing options...
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