Solar PV, pigeons, and micro-invertors

1

Hi all,
I am seeking help and advice on a number of related issues.
We have solar PV on our roof. I can definitely hear pigeons cooing on the roof seemingly under the panels. Reading on the internet suggests that pigeons roosting under the panels or even worse nesting is very bad news indeed. I have contacted a firm who say they put up pigeon guards all the time and say that for sure the pigeons will by now have damaged the MC4 connectors. They have quoted me a price for clearing out the pigeons and under the panels, replacing the MC4s if necessary and putting up pigeon protection.
However, they also are suggesting replacing the string connectors with individual ones from SolarEdge and a new SolarEdge invertor. I said we were not interested in any products from SolarEdge and they suggested Enphase instead.
So my questions:

  1. Do CC members have experience of pigeons and solar PVC? Do they do the amount of damage suggested and in particular is it likely the MC4s will need replacing.
  2. The invertor (and indeed the panels) are still under warranty (the system is 8 years old) and it seems anti-intuitive to junk a system that is still under warranty. Is this a sensible suggestion or not?
  3. Does anyone have any experience of SolarEdge v Enphase. Any knowledge of which is better and why?
    Thanks to everyone in advance.
    Alan
2

When I had my PV installed I asked for bird protection at the time. My installers said that it should be standard practice and was a cheap fit.

I knew of people with damaged systems, so was acutely aware of the potential risks, including anecdotally fires caused by sparks from damaged cable in the vicinity of nesting materials.

Once the installation is in place, scaffolding removed and the workforce gone, the price rockets.

Removing dietrus from under panels is as likely to damage cables as the pigeons are, so it could be argued that if you haven’t noticed a drop in PV generation then just block the pigeons from reentering and don’t touch anything more than a finger’s length under the panels. However you are likely to get rubbish caught on the lower edge of the netting as the material is gradually affected by gravity.

It is a matter of deciding on what is best for you.

If you have noticed a fall in PV output then you need to get the issue resolved, or decide to live with it. It is then that the old issue (if any PV issue can be called old) of microinverters versus string optimisers.

String optimisers will still connect to your existing inverter, preserving the investment you made in that. Microinverters replace the existing inverter. Neither are essential, particularly if your array is never shaded.

I have no knowledge of whether the MC4s would need replacing. It does seem unlikely to me. Although click fit they are quite hardy and need a tool to separate them. Whether pigeon beaks are effective MC4 extractors I don’t know. I would ask the installer for evidence.

If you are on FiT payments for your system any replacements have to be like for like. Anything which might increase your peak output to the grid, FiT or otherwise, needs to be notified to your DNO.

Quite apart from the above I like the idea of microinverters. They convert panel output to AC at the panel rather than at a centralised inverter. This avoids high voltage DC and makes the fitting of solar a DIY job for a reasonably competent householder. I wouldn’t fancy going on my roof to work but for a shed, summer house or gazebo they are ideal. In much of Europe fence panels or balcony panels are popular and they too are best fitted with microinverters.

3

Tim,
Thanks so much for this very full reply.
I wish I had known about the problem when we had them installed in 2015, but no one mentioned it then!

Your reply has given me considerable food for thought.

We have not noticed any particular drop in output from the solar panels (no more than would be expected from them ageing anyway). I have looked at the panels through binoculars and there is certainly no pigeon droppings on the panels themselves, and as far as I can see nothing under the panels. Nothing at all has been washed down in the recent endless rains. The only evidence of their presence is the endless cooing when I am in the attic rooms. All of which leads me to ask “Well how bad can the problem be?” I am wondering if it is actually more sensible to leave things until I detect an actual problem. This is partiucularly so if I have to faff about informing my DNO.

There is no way I could do anything myself as it is a 2 storey high roof and over a conservatory on the ground to first floor, so there is no access at all to the panels without scaffolding (not that I would want to be up on a 2 storey roof anyway).

4

If the price is reasonable to you I would suggest getting the netting. Once you notice a problem the price will rocket.

The netting might be possible with ladders rather than scaffolding, depending on the size of your array(s). That will keep the price down.

Unlike you, I have been on my roof, several times. I used to carry trays of tea up ladders to the builders and inspect their work. Carrying empty mugs down again seemed a lot more difficult!

5

Bit of an aside, but when I watched the two solar-PV panel installers (subcontracted to the main installer) setting up here a couple of years ago (being wary of any possible roof damage, but also just interested), I was taken aback to see them just propping a long ladder against the (two-storey) wall; one chap carried each (of 6) panels up the ladder, very slowly, carrying with one hand/arm, then the other man lifted it onto the roof, from above… no mishaps, but should definitely have been a scaffolding job.

6

SolarEdge kit it good. I have their 360W panels with built in optimisers and it all works fine, app is good too. It also allowed my installers to remotly monitior my install and check for issues etc.
At the end of the day, an inverter is an inverter is an inverter - there are minimal differences between brand - most people end up with the one their installer is most familar with / gets the best deal from the wholesaller on! That said I have installed SMA, Solar Edge and Solis and all were good and reliable.

Personally if I was going to replace an older inverter now, I’d look at the MyEnergi Libbi - with built in battery - more money, but solves two problems in one!

P.S. Installing individual optimisers on each panel will allow you to see which ones are working / better than others, so that might help detect a bird related problem…