PV Quote 12.3KW

Jonboy1889

Screwdriva said:

Jonboy1889 said:

Definitely helpful if you have that many panels!! I would love that level of monitoring (being a data analyst myself). You now just need scaffolding to fix them (and every time one goes wrong?)- it’s also quite possible that the reason the panels aren’t functioning is due to the faulty optimisers which have a much higher failure rate. 

Meanwhile all those without panel level monitoring are living in blissful ignorance 😂

If you watch the video linked above, you'll find optimizer failure rate is believed to be very low. Technically, higher than panels themselves yes but I can't speak to a specific install other than to say I'd be really glad to know when a panel (or 5) are down!

Not all roofs require scaffolding (ours can be accessed via a friendly neighbours velux window).

Yes he does mention that they are more likely to fail, but obviously doesn’t give any %s. I would say a no brainier then if scaffolding not needed and you can afford it! Esp with the warranty. I think what is bad is the myth that you need optimisers if you have any shading (/ you will lose the whole array), which simply isn’t true anymore and is a misleading marketing tactic.

Gary also makes the point that cheaper options are available to check your panel performance like an infrared camera - saves the need for optimisers on that front- and you know if that happens it must be the panel as that’s the only thing that can go wrong really (aside from the wiring I guess!)

Jonboy1889

One benefit that Gary doesn’t mention is how micro inverters (which are also optimisers) remove the need for a big chunky inverter in your house somewhere if space is a premium. It’s impressive how micro inverters work so well despite the insane heat under a solar panel!

one thing I’m finding is that too much heat is ironically not good for solar panel/inverter efficiency! 

Martyn1981

Jonboy1889 said:

One benefit that Gary doesn’t mention is how micro inverters (which are also optimisers) remove the need for a big chunky inverter in your house somewhere if space is a premium. It’s impressive how micro inverters work so well despite the insane heat under a solar panel!

one thing I’m finding is that too much heat is ironically not good for solar panel/inverter efficiency! 

Bit of a digression, but you may find this funny. I was always mocked on here (entirely friendly) for using our small downstairs toliet as our 'power room' for the 3.58kWp ESE array. You could actually check generation whilst having a pee (at least males could).

This is just to show how things have moved on.

So first pic is with the two big and heavy SMA inverters, 1.2kW on the left, and 2.5kW ahead.



Their weighted average efficiency was ~94%, so ~6% of gen became heat, and the toilet, even with the window locked partially open, was pretty hot.

We then upgraded to Solaredge, and were able to use a single 3.7kW inverter*, and things got a lot smaller, and at around 98/99% efficiency, the losses and heat output, reduced by about 5/6ths.



It's amazing how quickly things have changed.

*The ESE was made up of two arrays, a 30d pitch main roof using 13 185Wp panels, and the lower 20d pitch roof using 5 235Wp panels. At the time we couldn't find a dual MPPT inverter that could cope with the two extremes, especially the lower MPPT voltage for the smaller system. But there are inverters now that can do this.

69bertie

Jonboy1889 said:

It’s impressive how micro inverters work so well despite the insane heat under a solar panel!

And what is that temperature? I'd have thought the heat would rise off the panel with the inverter underneath in the shade being relatively cooler compared to the panel above. From playing with thousands of inverters at work (big machines) I tend to find small inverters don't tend to get very hot. Warm yes but hot, no. And they tend to last for years i.e. decades

I too have gone the micro inverter route plus battery. I can see everything that is happening with the inverters. No guess work, maybes etc. If anything, when it comes to getting an install, I never realised also just how much a difference the batteries would make to our consumption off the grid, both usage and cost wise. I keep on thinking I might add yet more battery capacity.

Jonboy1889

Martyn1981 said:

Jonboy1889 said:

One benefit that Gary doesn’t mention is how micro inverters (which are also optimisers) remove the need for a big chunky inverter in your house somewhere if space is a premium. It’s impressive how micro inverters work so well despite the insane heat under a solar panel!

one thing I’m finding is that too much heat is ironically not good for solar panel/inverter efficiency! 

Bit of a digression, but you may find this funny. I was always mocked on here (entirely friendly) for using our small downstairs toliet as our 'power room' for the 3.58kWp ESE array. You could actually check generation whilst having a pee (at least males could).

This is just to show how things have moved on.

So first pic is with the two big and heavy SMA inverters, 1.2kW on the left, and 2.5kW ahead.



Their weighted average efficiency was ~94%, so ~6% of gen became heat, and the toilet, even with the window locked partially open, was pretty hot.

We then upgraded to Solaredge, and were able to use a single 3.7kW inverter*, and things got a lot smaller, and at around 98/99% efficiency, the losses and heat output, reduced by about 5/6ths.



It's amazing how quickly things have changed.

*The ESE was made up of two arrays, a 30d pitch main roof using 13 185Wp panels, and the lower 20d pitch roof using 5 235Wp panels. At the time we couldn't find a dual MPPT inverter that could cope with the two extremes, especially the lower MPPT voltage for the smaller system. But there are inverters now that can do this.

that is a very substantial improvment!! Both in space and efficiency.

do you find the SE gives off a lot less heat now?

a friend of mine reckons he needs a fan for his inverter in that attic but this was 10 years ago install. My inverter is in the attic and I do wonder about heat, but so far not real loss of efficiency from what I can see on hotter days (maybe 1kw out of 30? But difficult to know if like for like). Will wait until July/aug before making a judgment!

Screwdriva

Jonboy1889 said:

Gary also makes the point that cheaper options are available to check your panel performance like an infrared camera - saves the need for optimisers on that front- and you know if that happens it must be the panel as that’s the only thing that can go wrong really (aside from the wiring I guess!)

You'd be surprised how many times I've seen wiring chewed straight through (rodents and parakeets of all things)!

Martyn1981

Jonboy1889 said:

Martyn1981 said:

Jonboy1889 said:

One benefit that Gary doesn’t mention is how micro inverters (which are also optimisers) remove the need for a big chunky inverter in your house somewhere if space is a premium. It’s impressive how micro inverters work so well despite the insane heat under a solar panel!

one thing I’m finding is that too much heat is ironically not good for solar panel/inverter efficiency! 

Bit of a digression, but you may find this funny. I was always mocked on here (entirely friendly) for using our small downstairs toliet as our 'power room' for the 3.58kWp ESE array. You could actually check generation whilst having a pee (at least males could).

This is just to show how things have moved on.

So first pic is with the two big and heavy SMA inverters, 1.2kW on the left, and 2.5kW ahead.



Their weighted average efficiency was ~94%, so ~6% of gen became heat, and the toilet, even with the window locked partially open, was pretty hot.

We then upgraded to Solaredge, and were able to use a single 3.7kW inverter*, and things got a lot smaller, and at around 98/99% efficiency, the losses and heat output, reduced by about 5/6ths.



It's amazing how quickly things have changed.

*The ESE was made up of two arrays, a 30d pitch main roof using 13 185Wp panels, and the lower 20d pitch roof using 5 235Wp panels. At the time we couldn't find a dual MPPT inverter that could cope with the two extremes, especially the lower MPPT voltage for the smaller system. But there are inverters now that can do this.

that is a very substantial improvment!! Both in space and efficiency.

do you find the SE gives off a lot less heat now?

a friend of mine reckons he needs a fan for his inverter in that attic but this was 10 years ago install. My inverter is in the attic and I do wonder about heat, but so far not real loss of efficiency from what I can see on hotter days (maybe 1kw out of 30? But difficult to know if like for like). Will wait until July/aug before making a judgment!

Yep, far less heat. Basically (hope I get this right) the losses are given off as heat, so 1/6th the loss is 1/6th the heat. It's one of those slightly deceptive tricks, where you think 94% and 99% are close, but the 6% v's 1% are the true story. If I remember correctly the SMA1200 was 92% efficient, and the SMA2500HF was 95%.

Our WNW system has the inverter in the loft, but it's fully insulated, including the roof, plus a velux that's opened during the summer. Something that I think surprised many of us on here back in the 2011's+ when we were working through all the issues, is that the PV panels themselves stop the direct sunlight onto slates/tiles. So the loft with PV will more reflect ambient temps, whereas before, especially if the slates/tiles are exposed internally, the heat would reflect their temp, in the sun, so high 30's even 40's are possible in a 'normal' loft. But as a rule, leccy equipment is more efficient in colder temps, and tends to have a longer life expectancy - so lofts aren't a no-no for inverters, but common sense is required, and not ideal in ones that get really hot, where all of the sun's 'attention' won't be blocked.

Magnitio

ispookie666 said:

The usefulness of panel level monitoring - system installed in 2015, no shading 

But do you know whether it is the panel or microinverter that is causing the lower output?

JKenH

scubajoe said:

ispookie666 said:

The usefulness of panel level monitoring - system installed in 2015, no shading 

Indeed, definitely a plus.

If we ignore the black panels and the dark blue 37.5 Wh panels, is it reasonable to assume the rest ranging from 53 to 62.25 Wh constitute natural (acceptable) variation in panel output? The lowest is 15% below the highest. Does anyone else with Solar Edge see this level of variation between panels? Perhaps other contributors with SE could post a few screenshots.

Despite the apparent degradation on my panels, last week I had the best day’s PV output for 2 years. I don’t have SE but having identical strings on the same roof does let me see I have a problem. It may be that many solar PV owners are suffering some degradation of their panels but are unaware as it is masked by the natural variations in the weather. 

ispookie666

@Magnitio interesting point. I would have thought the failure from the micro inverter would be all or none.