We’ve just got back from holiday and switched on the heat pump to heat the hot water. It was doing this while we were sitting in front of it having lunch in the garden. The air that comes out of the front is 10° cooler than the ambient temperature, which kept us lovely and cool. Clearly it’s not something we’d do regularly but it was lovely while it lasted.
Just reading the posts above, how are panels actually fixed to a pitched roof? Are there brackets that attach to roof joists and so do tiles / slates have to be removed, cut and replaced? What happens to felt or waterproofing that might be under the slates?
Yes, slates are removed to allow brackets to be screwed to the rafters. Horizontal rails are fitted to the brackets.
Thanks Chris, so slates or tiles will be cut around the brackets leaving possible gaps and any water barrier ( I have felt under my slates) will be penetrated, sounds like a recipe for water ingress if not done carefully particularly with multiple panels
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In my case they cut a small groove from the underside of the tile, so top down view you would not know. It still therefore overlaps the lower tile, and had no issues in 7 years
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We went for integrated solar panels. Our roofing felt had failed and we wanted to improve our insulation so we stripped the roof back to timbers, added high quality insulation material and then fixed the panels on that and tiled around them with the best of our old tiles. We now have a good stock of spare tiles.
No worries about wind, leaks, birds’ nests etc. - worth considering if your roof needs fixing anyway.
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I would search, but NHBC have a guide. There are special flashing though for the brackets that integrate with the tiles.
Phil
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Yes, one of longest parts of our roof installation was cutting the groves under the interlocking tiles to accommodate the fixing brackets for the horizontal rails that the panels are fixed to. This took the roof guys the best part of a day to do (along with the dust and the noise). IIRC, about 34 tiles.
A very neat job in the end where the brackets slot under the tiles, the refitted tiles look the same as they were before the brackets were installed and the integrity of the roof is maintained. All part of the service that a MCS certified installer should perform.
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I remember my installer saying that some installers didn’t bother to do that, so the tile would lift in the wind and cause potential damage. A lot of his jobs at the time were going around fixing other installers mistakes.
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Not surprising. A lot of cowboys around, especially in the early days, the company long since dissolved before the hidden installation bodges reveal themselves…
Still ongoing shenanigans with Octopus.
My export MPAN was generated within a few days of applying but Octopus seem to be having a lot of issues taking the export MPAN over to them from the central switching service and today the process failed again (4th time !)
I’ll be WFH tomorrow so will take the opportunity to phone them and see what is going on. It’s not rocket science so should be straightforward to sort out, albeit Octopus specialist team don’t seem to be able to manage that.
Any useful pointers appreciated !
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It took Octopus a long time to get my export set up when I switched from EoN, having been with Octopus previously. I don’t know what the issue is as I never got an explanation as to why.
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Persistence! My experience with Octopus is that they want to help you, but their advice can vary from one person to the next, and as you have found, sometimes things that should work don’t. If you keep on asking them nicely I dare say you’ll get there eventually.
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Now that Netzero supports Ohme charge points I’ve signed up for 1 month to test it out.
My first test charge (with both my Ohme Pro added and IOG integration selected in Netzero) my EV started charging at 8pm (a Smart Charge slot outside of IOG off-peak hours) as did the Powerwall 3! As soon as the 30 min slot ended my Powerwall 3 exported it all again 
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With an Expansion Pack the system charged up at between 9 kW and 10 kW during the Smart Charge slot in Savings mode (previously called Time Based Control). So a nice bonus.
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Thanks chaps – it sounds like patience is the key here.
Octopus have been keeping me updated via email, but I decided to phone them to get more info.
My Export MPAN was created within a couple of days of first applying for export so that is in place with the DNO - that part worked fine. Where it seems to be going wrong is an extra step in the process which has been recently introduced.
When Octopus try and switch the export MPAN over to them it fails as it can’t find the Export MPAN, so it appears it’s just not rippled through the Central Switching Service database. The advice Octopus has been given is to just keep reapplying, which seems rather inefficient.
The gentleman I spoke to thought it should have been enough time now for everything to work since the MPAN was created on the 15th of June. They have scheduled the switch (again) for the 14th of July.
Fingers crossed that this time it will work !
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Good to hear a bit more detail from Octopus on this. Thanks.
My experience with Octopus setting up my export account was much better than @james_n reports. It took a week from when I sent them the email that I had from UKPower Networks with my export MPAN in it.
But I had to get Octopus to sort out why the reporting of my export readings had vanished from the app and then I had to get Octopus to do whatever was needed to pay me (by crediting my account) for power I exported. That step was quite quick and they say that it will happen automatically now every month. I get the impression that they haven’t really got the infrastructure in place for handling exports as a normal thing. Certainly all the messaging is the normal “welcome to Octopus” stuff, as if it were electricity and gas supply being taken over by them from someone else. Similarly the export messaging is all about them taking over an export meter than was previously being read by another energy company.
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The biggest challenge we find - especially in more rural locations perhaps is the amount of bird droppings and guano on the panels.. sure after a good shower most washes away - but after a few weeks of dry days it starts to get visually noticeable… though Id be hard pushed to define a drop in effectiveness - but it must have some impact.
But yes there are typically no issues with leaks or wind loading on a pitched roof - and nests are easily deterred with simple netting.
One benefit I am told on roof panels is the cooling convection underneath to help maintain efficiency. I am not sure how cooling is achieved with in built roof panels. or even PV tiles which can work well as they look like slates and are almost completely visually transparent…perhaps these methods just take a temperature efficiency hit… there are always compromises.
There are even PV bricks for walls now too (BIPV)
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All these are valid points and will vary according to local circumstances.
Our panels have been up for nearly 5 years and have never been cleaned or serviced. I agree that heat impacts efficiency - we have peaked at around 80% today in 30+ temperatures - a week or so ago we were hitting full rated output so the drop must be heat related. I rarely get to see them directly but as of a few months ago they looked remarkably clean. We are also in a very rural area and wind is my main concern but so far so good.
Ours are coming upto 2 years - at first I was paranoid about keeping clean - now we let the rain do it - seems to work well. I must admit not heard of servicing other than occasional visual inspections.. I know what you mean about wind - we are on a ridge and westerly with a view of 15 plus miles .. fortunately since we have the panels up we haven’t knowingly had gusts above 60mph. Its my flat roof panels that are more vulnerable and they and their holder frames are graded to at least hurricane level winds with appropriate ballast so I am informed … and yes in 1987 we did have a hurricane here, with much building and infrastructure damage and swathes of flattened nearby forest… which has now largely recovered 
Yes I think haze also affects things - and on very hot sunny days it can get hazy (we are close to the coast) and so that impacts generation… and fortunately benefitting from the effects of the east coast in East Anglia we are noticeably cooler - I think we peaked at 26 to 27 degrees for a short time this afternoon which was hot but too hot, and towns and villages right on the coast were around 24 degrees - whilst much of central and southern England & Wales were hovering around or above 30 degrees. Its certainly refreshingly cooler as I type this.
I think it is fair to say for many when we install a new PV system with battery and inverter etc we get obsessed with it - optimising automations - checking optimal generation and export etc - I was one - but I was told likely within 6 months I would be bored with that and just leave it do its thing.. Indeed they were right ..
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