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Abstraction is ok if you don't need exact timing and total control of the hardware! When you have self-destructing hardware with high energies around it's a bit better to have cast iron control of what's going on or BANG :unsure: usually expensive!! Ohh I wouldn't countenance anything...

Yup just like here in Lincolnshire, I wanted to absorb those peaks without chopping them off by interfering with MPPT straight away and in many cases the average is nowhere near any sensible limit hence the thermal limiting by averaging over a long period as what I am really trying to do is...

It's my own design and it is rather customized in that it is directly connected to a water tank heater that always gets priority any surplus being sent to the grid with export strictly controlled (as I don't get paid for it). The software is entirely assembly language for speed running on a...

So to summarize your commercial inverter doesn't really have the facilities needed to control multiple parallel strings, I am not surprised as the available controls seem very limited. In your specific case the new string would be connected by a cable having a loop resistance of an Ohm, quite...

Yup you got it exactly! There are some plots on another thread of mine illustrating this here

See post #7!

Well by the sounds of it you really are going to rely on that fuse for fire protection so I hope you take into account the mounting and cooling of that cable in calculating it's hoped for ampacity!

Ahh very interesting, do you know what Voc is for your array (measure with breaker open) then set the target voltage maybe 20V below Voc and make sure it sticks there as it's only operating point. I think your comments with a commercial product and similar parallel strings very relevant to this...

IMOP that's quite likely a dangerous assumption, after all, it want's 5500W+losses from the input and it will use whatever combination of volts and amps it fancies to obtain it!

I think this is confusing MPPT & "target voltages" maybe ? Surely this "target voltage" is constant voltage and is a mode that avoids the use of any MPPT algorithm at all.

I found the manual so impenetrable I could not find any reference to those settings however fixing the array voltage is not going to limit the available current! Are you saying you would use a wire and hence a fuse below Isc for those panels ?

Longevity of the inverter and panels! Ohmic losses (heat) increase at the square of current so if the opportunity arises to run at 10A vs 15A I will take it. Peak to average ratio is also important in the PWM as it affects transformer and inductor dissipation and so running at different PV...

It all depends on weather your array suffers shading (as mine do) and large variations in temperature (most do), both cause vmpp to shift around in voltage at times quite dramatically, I can for example be running on only one of four panels(others being shaded) so vmpp is only one quarter of...

Well there are actually two loops, an inner PID loop that controls voltage, that is it continuously adjusts the PWM to maintain a set PV voltage and then there is the outer MPPT loop that runs much slower and determines the setpoint voltage for the PIV loop. In the case of the periodic scan MPPT...

Hello I have a ~1Kw inverter with two ~1Kw PV strings in parallel pointing in slightly different directions. As expected MPPT handled the combination with no problem even though there was a voltage difference. However what I was not expecting is that when up against the inverter power limit in...

I thought about doing that many times but abandoned it on economic grounds, however I tend to use more strings in parallel now to reduce the dependency on shaded panels and also advanced inverter software to find the true mpp of the array. What did you decide to do ?

I dream about having a roof like that BUT is it the perfect pitch!! Always some drawback somewhere and what about trees and other buildings......

Dead right there reckon Ebay have gone right off the boil on solar......greed! Have you looked at city plumbing, good panel prices & free delivery over £80ish, very handy especially if you just want a few extra for filling in or some mounting rails. If I had the space completely agree with your...

I don't think you are reading it right, it means no part of the installation can protrude more than 200mm from the roof covering (tiles or whatever) so that pretty much rules out tilting of any kind. Of course it may be out of sight out of mind but don't forget to allow for wind lift that can be...

Beware UK planning rules especially if it will be visible from a road or you have neighbor problems. Quote : Development not permitted A.1. Development is not permitted by Class A, in the case of solar PV or solar thermal equipment installed on an existing wall or roof of a dwellinghouse or a...

Ahh yes but that would be more equipment at more cost. The purpose of the post is to show what can be done at minimal cost to improve performance, in this case by having arrays with different sky views. Depending upon the inverter it may be possible to add dissimilar strings without investing...

What you need to take into account is the distance through the earths atmosphere the sunlight has to travel before hitting your panels, atmosphere seriously attenuates sunlight due to suspended dust, water vapor et etc. So the lower the sun is in the sky the lower the panel power even if they...

Hi all I have my own inverter design and a while ago I added periodic (~ every 10mins) voltage sweep to it so the MPPT could be kicked off of subsidiary peaks caused by shading, this indeed has worked very well. Now I have added a secondary array of panels on a Pergola roof to get a little more...

Have you got your G99 permission from your DNO yet ? If not cable sizing is the least of your problems. I suggest you try this UK based forum as they are pretty knowledgeable on UK regs UK solar

Well it's just a bit more complicated than you implied, definitely it's a NO on an existing ring circuit. An excerpt from G83 that I believe still applies and what I had to comply to reads " An inverter supplied from a PV array must preferably be installed in a dedicated circuit in which: no...

What electrics forum was that then ? Sounds like you are one of the headstrong "I will do what I like brigade". My advice to you is either hire a qualified electrician to tell you the rules OR read them yourself, presently you seem to be seriously misinformed.

Thank you for the great pictures :) I confess to not being aware of the shaft seal :oops: Mine has been in service since 2017, perhaps if you examine an older unit that has been outdoors you might find the lid seal less than perfect. In any case I prefer not to expose directly to the elements if...

Just a quick note on the IMO, I use it and it's brilliant BUT it is not suitable for use outdoors unless protected because, 1/ The cable glands are not waterproof 2/ There is no waterproof seal around the operating mechanism 3/ The seal between the case halves is very flimsy and liable to have a...

That video way back in post #1 is very misleading. It quotes a fire authority who have no electrical engineering expertise simply based on there observations. I have personally observed in many instances incorrect equipment being used for DC breakers, most typically components designed for use...

Greetings! On a freezing cold January day I got this from my 1Kw ground mount Same old shading problems, I would love to fill in those gaps where the power production is near zero, for those with very poor solar resources every little counts. EDIT 16th Jan, I found out what the gaps are, they...

Hello, I can add some information here as I actually designed some additional software for my inverter to do this sweep periodically, thread here The primary purpose is of course to jog the mppt off of false maximum power points when the shading diodes are in action, for my array typically at...

I would be very careful of Octopus, I left them as they changed direct debits almost continuously without warning and disabled my ability to control them, it seemed to me there intention was to build a large balance in there favor instead of allowing me to pay for the energy I used. I now pay...

I can help you with the green slime, it is caused by sunlight. On my IBC's I used for garden irrigation I forced heavy black polythene sheet between the steel cage and the plastic container and covered the top so no sunlight could get in, result, no green slime.

I had an istabreeze many years ago, I think supposedly 600W but of course it was not anything like that! I don't think there claims were any worse than other similar units all of which seem to claim very high outputs. The construction was flimsy with the bearing just push fitted into a plastic...

I am impressed you have done your homework, yes it helps a lot to stretch production at the start and end of the day, but I am always looking for more improvements...........