Dillsue

You'll not go far wrong in following Octopus's trial process for accepting non MCS systems onto there export tariffs. They are asking for proof that the roof can take the load by way of building control sign off, and an electrical installation test cert.

If youre not modifying the GSE trays and fitting panels to GSE spec, then why would you need to change the GSE intended ventilation? On a still summers day there wont be any wind rushing around to cool the panels so you'll just be relying on convection

You keep mentioning "application" but if you're under 16amp max export its a G98 notification. All the DNOs should be working to the ENA G98 specs so there should be little difference in what you submit. For us, SPEN wanted- Single line diagram of the house wiring specifucally showing the location of the lockable PV isolator, which is what youve got. Completed commissioning form with the signature of whoever checked the install which should be your spark although thats not always the case. Details of the ENA type test certification for your inverter(s) BTW your roof install looks neat

You need to calculate the DC output from your split array before you speak to your DNO. Telling them you've got 9kw of panels, which you'll never get 9kw of generation from, is much more likely to get a refusal than say a calculated max of 5 or 6kw As johnmo mentions you can have any size inverter you want if you install export limitation. That set up allows you to power the house with as much as you can draw from your PV/batteries but only export what your DNO has agreed.

You'll likely get those on single phase easily as they don't all hit max generation at once and you'll do well to get 3kw out of the NE array. If you put each array into PVGIS separately, download the hourly figures for each of the 3 arrays then use Excel to combine the 3 data sets, you'll be able to see what your max DC generation is. You'll then be able to size your inverter. One of our 2 systems has 8.5kw of panels spread over 3 compass points and the calculated max output is 5.4kw You've already mentioned Solaredge and their inverters will handle way more input than the inverters rating, so you can have a seemingly large array hooked up to seemingly small inverter. What's the peak demand that you need for the house?

How much PV have you got on each pitch and what direction is each pitch facing?

If you "tee into the shed feed" your calcs go out of the window as you ve got 8.5 kw in the section of cable from garage to inverter. You're probably best getting a spark to spec all this for you and test it when it's done

Extensions to a FIT system don't have to be by an MCS installer. If they are MCS installed then you can get SEG for the additional capacity. If they aren't MCS then you can't get SEG. The original FIT registered capacity continues to get FIT generation payments and the option of deemed or metered(SEG) export payments. Deemed export is only available if you're on the FIT scheme. SEG is always metered through the service meter, not the generation meter. Maybe changes on the way for non MCS extensions if Octopus decide to buy non MCS export......... a while off and a few hoops to jump through though

If your hubby is an electrician then he just needs a roofer to help with the roof work and DIY is straight forward. Buy or borrow a used scaffold tower and flog it afterwards. You'll likely pick up a 4.5kw kit(excl battery) for under £3k and the parts for much less if you are prepared to wait and buy as things as they come up on ebay

Do GSE do a design service?

I'm not aware that fitting roof hooks interferes with any of the interlocking at the sides of tiles- all thats needed is a notch at the bottom of the tile. Tiles are regularly cut for all sorts of roof features- dormers, veluxes, hips, valleys etc so I don't think there needs to be too much concern about notches for roof hooks. Factory moulded notches would be awesome but getting the notch in the right place to match the hook would mean a selection of pre notched tiles which I guess is why they are site cut??

Why would fitting roof hooks reduce the lap? The realtively few ones I've seen and done are notched to get the tile to sit neatly over the hook but theres no reduction in lap??

So get your spark to install the cabling and a roofer to fit the panels.

Not sure if your drawing is to scale but it looks like you may be able to juggle panels on the south facing pitch and maybe those on the west to get an extra panel on each pitch?? If thats the case then move 2 panels off the east onto the south and west faces and use a dual MPPT inverter with one pitch on each MPPT input. Save the cost of optimisers. Personally I'd go for a solaredge system but I can understand the concerns over the cost..... I would at £16k. Have you priced up the parts as that seems a hell of a price.

Highly unlikely to cause any hazards, but connecting type tested kit to manufacturers instructions isnt the problem. There was a video posted in the PV section a few days ago showing how to hook up an EV for a home cooked V2H set up in the US. I think someone in the UK was taking jnspiration from it? Not far into the video the guy shows his distribution board/consumer unit with 2 separate incoming supplies, one for his "off grid" V2H set up and one for the grid connection. No interlocking between to 2 breakers so both could be on at the same time connecting the home cooked mains V2H to the grid. The guy knew he should have them interlocked and even said he might "put a piece of wire between them" or "3D print something", presumably to cook up a home grown interlock. That's where the problem will likely lie if people think the absence of MCS means things have been deregulated. Be good to see Octopus implement a chargeable inspection before they accept a non MCS system for export

The DNO does make sure the grid is safe by insisting only ENA compliant kit is connected. Home owner is responsible for personal safety including that of the linesmen working on the grid where any hazard comes from the home owners premises, on their side of the service fuse/meter. See National Terms of Connection.

?? I thought your post was about looking for installers??

I think theres a handful of EVs that support V2G/V2H and I'm fairly sure they plug into a 2 way charger rather than a solar inverter. I think I read about a 2 way charger that also has solar inverter capability but not sure if it was available/approved for the UK. If youre looking to use V2x then your best bet is probably install your inverter and cables near to where a future 2 way charger would go so you can hook up your solar when the time is right.

They are trialling the principle so its not available to everyone just yet

Sounds like you're unlucky or expectations maybe too high? Online sellers seem to have plenty of stock. It's summer holidays so every company has lots of people on holiday and may be struggling to fulfil existing orders. If youre trying to add to the workload then you might encounter some reluctance to take on the work. Good installers will likely be booked up for weeks or months in advance so you wanting them to start soon may be being overly optimistic. Maybe hold on til the autumn??

Exactly that. They'll only make FIT payments on the FIT registered capacity which for you is 4kw. If you double the system size to 8kw then paying for 50% of your generation is paying only for 4kw of generation

Not sure they are actually accepting customers as they sent me this on the 8 August- Hello We don't currently accept export customers without an MCS certificate, but we're in the very early stages of trialling a solution for non-MCS customers. If you or anyone you know would like to hear if this becomes available, pop your name down here: https://octopus.typeform.com/to/UAbK9bRq Kind regards, Harriet Octopus Energy Ltd is a company registered in England and Wales. Registered number: 09263424. Registered office: UK House, 5th Floor, 164-182 Oxford Street, London, United Kingdom, W1D 1NN On Fri, 04 Aug 2023 at 20:50, phill.edge@yahoo.co.uk wrote: Hi. I've just read your Export Tariff Terms and Conditions and sections 5.7 and 5.8 seem to suggest that MCS accreditation isnt necessary? Could you confirm this please?

That would be a G99???? We have 7.4kw agreed export on 1Ph so dont bank on having to have 3 ph.

Fingers crossed for you. Be nice to have a precedent set. Been watching 6.5kw disappear into the grid for free since late morning!!

I'm not looking to hold them to account over "lying" as lots of people in all walks of life including large seemingly professional organisations get their knickers in a twist over things they should fully understand. I'm hoping that repeatedly going back to them with a solid argument as to why they should accept non MCS export will eventually land on the right desk and trigger a memo to all their teams clarifying their TS and Cs. It's hard to see a more solid argument to accept non MCS export than their own TS and Cs so let's see how that plays out. Just weighing up adding more PV if its a goer:)