Solar PV Supplier Midlands?

[Mr Sandman]

Looking for a reputable and good value PV installer for a few properties i have id like to install PV on. Any recomendations? Ta Steve

[alan_m]

Are solar panels now economically viable with reduced/no FIT subsidy? What now is the typical payback/break even period, assuming that electricity prices may be 2x higher in 5 years time.

[The Natural Philosopher]

Almost certainly not

P Probably longer than the panel lifetime Although we are now seeing the effect of subsidised renewables driving energy prices off the scale,.

[alan_m]

Surely not with all the "free energy" from the sun and wind. ;) :)

[The Natural Philosopher]

Well coal is free energy from the sun too

[Tim Streater]

So is oil, come to that.

[Theo]

Let's run some numbers:

330W panel: £111.80 (Jinko) 3kW inverter: £310.70 (Growatt)

So let's say you could buy parts for a 10 panel system for ~£1.5K+VAT. (prices from Midsummer Wholesale who aren't super cheap, but just have an easy website)

That's not including the mounting system, which could vary quite a lot depending on what you have, access requirements etc. If the roof is partially shaded you might need optimisers too (about £35/shaded panel)

And then there's all the sundries - consumer unit, isolator, cables, etc which will depend on your setup. Maybe another £200-300.

Perhaps total £2200 + mounting + labour. And that would get you

3648kWh/year on a south facing unshaded London roof, and if it displaces usage on a current tariff of 20p/kWh it would pay back the parts bill in 3 years. Less so if you need to include a battery to timeshift usage.

So it really comes down to your mounting solution: if it's going to involve complicated scaffolding and roof mounting systems, that's going to bump the cost. If you're replacing the roof anyway, or is an easy DIY job (outbuilding or something), it would seem a no-brainer.

Theo

[alan_m]

Government figures for May 2021 suggest around £1.6 to £1.7K per kW (peak) installed. Say, £5.5K for your 3.3kW (peak) installation

Other sources give a typical annual output from 3.3kW panels at around

3000 kWh from an ideal south facing installation.

3000kWh @ 20p per kWh = £600 (per annum)

so payback under 100% ideal conditions is more like 9 years.

If the panels are not ideally sited the payback will be longer.

Solar produces least when you need the energy most - during a cold winters night. If the use of gas/oil is going to be discouraged for heating then solar will will have a diminishing part of reducing annual household bills.

[Andy Burns]

But that's not going to get you a grid-tied system (approved installers only for Smart Export scheme, and I bet they want to supply the kit at higher prices) so would not be easy to use the output ... fridge freezer and immersion heater?

[Steve Walker]

Which is part of the rip-off. I can see the need for approved installers to install the connection from the approved control/switching device to the mains supply, but the rest of the installation could be installed by anyone and checked over or even a plug-together system, requiring no checking.

All government schemes seem to come with "approved supplier/installer" lists, where any grants are completely cancelled by higher prices than everyone else.

One example from years ago was when I looked at converting my car to LPG. There was a government grant available. All the installers on their grant approved list were higher in price than the independents by exactly the value of the grant! Considering that all installers were required to be trained and licenced anyway, what good reason was there for approving only a subset of installers?

[Andy Burns]

A lot of the PV installer websites are shy about their prices, wanting you to fill in a form with contact details and they'll get back to you, but this one at least gives sample packages

9x 340W panels plus a 3kW inverter fitted from £3,780 if you want a "massive" 4.8kWh battery that's another £3,240

[Theo]

Yes, it makes a lot more sense if you have local usage for it. Either say an EV, timeshifting your loads (dishwasher, washing machine, etc), or just having sufficient baseload that any solar displaces grid demand (more relevant to businesses, although some people have more demanding equipment at home).

If you can't do that, your loads are a bit lower return (ie you wouldn't have otherwise run them from grid electric) - immersion (when you could have used gas), an EV if you're on a cheap overnight charging tariff - so it's 'free' but you wouldn't have paid full price anyway.

With a battery it makes a lot more sense, but we aren't quite there on battery cost yet (mostly lack of volume I think).

I'm curious what the OP wants to install for, BTW. If these are rented properties, he's spending the money and the tenants are getting the benefit of lower bills. So I wonder how that's worked out - does he get cashback from the tenants' electric bills or something? Or just that it makes them more attractive and so he can charge higher rent?

Indeed, that's annoying. However the way to think about the grant is that you, as homeowner, don't get any benefits. What they're about is training up the industry and stimulating demand for the kit. The equipment price comes down, and now there's xx,000 installers who know how to install it. So they taper off the grant and now you can go to the regular market and pick up an unsubsidised quote at a lower price without any grant support.

The problem here is the 'MCS certified' which means even if someone is trained they can't do a grid install unless they're in the (paperwork-infested) club. Although I don't know if you can get an MCS person to connect up an install that's already been done?

Theo

[Andy Burns]

I think this answer (to a slightly different question) on the MCS website tells you what you already suspected ...

Q:

I?m MCS certified and have been sub-contracted to complete some work for another Installer who isn?t MCS certified, can I complete an MCS certified installation?

A:

No, in order to ensure compliance with MCS 001-1, only MCS certified Installers can enter into contracts directly with consumers.

If you don?t hold the contract directly with the customer, you won?t be able to raise an MCS certificate. The Installer signing the contract with the customer needs to be able to verify that the work undertaken on their behalf meets the MCS Standards. If they?re not MCS certified themselves, they won?t be eligible to do this.

[Andy Burns]

I hadn't seen DIY install systems before, ok so you won't get any FIT/SEG payments, which are a pittance to start with, but it seems like you *can* DIY install the kit, provided the hardware is MCS certified and G98 grid-tied so you don't fry the DNO's staff ... is that legit? Looks it from the PDF on the tech info tab

Not amazingly cheap though ...

[Theo]

Yes, I'd seen those kits:

that's what I was vaguely thinking of when talking about DIYing.

They use microinverters - while you can get a Chinese microinverter on Aliexpress for £30-40 they aren't G98 certified, and the ones that Plugin use are about £100 per panel. When you can get a 3kW inverter for 3x more, it's not a cost effective way to go.

But it's interesting the way they do the DNO paperwork and I wonder whether, by using microinverters, they manage to fly under the radar in some way. I know G98 has special dispensations below 800W per inverter, so maybe it's related to that. I should probably read up some more...

(I had originally started looking into this on the basis of duplicating their setup, but then discovered how cheap regular inverters have become now)

Theo

[Andy Burns]

I suppose for a novice DIYer it means just 50V DC wiring between pairs of panels, rather than about 500V DC for a complete string, but as you say, no reason not to use a "proper" inverter

For G98 (where you inform the DNO) the limit is 16A per phase. If you want more than 16A (on the AC side) you need to ask the DNO for permission and use G99 kit.

You can search approved inverters, e.g. 3.6 to 3.68kW

Interesting, but without an MCS installer cert you're "unlikely" to find a SEG tariff likely to accept you (if you have a cert they must accept you, if you don't they can accept you, so it's not cut and dried)

If you generate more than you can consume then obviously the extra will get exported anyway, without you getting paid, what happens at the meter, do they still go "backwards" thereby saving you ~15p/unit exported, or do the meters just disregard it?

[Chris J Dixon]

No meters these days are intentionally allowed to run backwards with PV, though there may well still be some that do.

There was an interesting quirk with a certain electronic meter which was capable of monitoring import and export separately. As an anti-fraud measure, it could be configured by the supplier to add the two together, so you paid regardless of direction of flow.

Those unlucky consumers who added PV with a meter thus programmed found that the more the sun shone, the higher their bills became. There was quite a lengthy thread on MoneySavingExpert's forum at the time.

Chris

[Theo]

That's true. I did wonder whether there were multi-string inverters. That would avoid needing optimisers - just run individual panels into the single inverter, which would also keep the DC voltage lower.

I'd need to read up on safety of solar systems too - are there particular earthing and protection requirements?

I presume you can overspec the panels, there's just no point getting more than a 4kW inverter unless you want to go G99.

Interesting, I hadn't seen that.

I think all smart meters, and maybe some non-smart meters, have separate readings for import and export units. So they can tell the difference.

I did wonder how they know whether you have an MCS cert if your meter is already reporting export, but it seems you can't switch to an export tariff without one. Although Ofgem say:

1.12. For PV, wind and micro-CHP installations up to 50kW, applicants will be asked to demonstrate that their installation and installer are suitably certified. You may have an installation certificate to demonstrate this. This may be a Microgeneration Certification Scheme (MCS) certificate, but the SEG also recognises that other schemes may be equivelant to MCS. 1.13. If you do not have an MCS certificate, your installation and installer should be accredited in accordance with EN 45011 or EN ISO/IEC 17065:2012. You should speak to your chosen SEG licensee to understand exactly what information they need from you. 1.14. If you are unable to demonstrate that your installation is suitably certified, a SEG licensee is not obliged to offer payments under the SEG, but they can make payments if they wish.

So it sounds like they can accept you without MCS if they want to. It seems that 'Flexi-Orb' is another standards body equivalent to MCS - I don't know if the requirements on installs/installers differ.

Theo

[Andy Burns]

I don't think any inverters greater than 3.68 kW can have G98 approval.

Yes, as I said above, if you have an installation cert they must accept you, otherwise they can accept you, but I get the feeling they'd be unlikely to.

So having MCS certified kit means you're allowed to install it, but unless you use an MCS installer you'll probably be giving your surplus away, overspeccing just means you're paying more upfront in order to give more energy to the grid for free?

It seems the technical/approvals part of MCS is about safety and you can DIY that, the "jobs for the boys club" part of MCS is probably more about avoiding fraud against the SEG tariffs?

Obviously Nov-Feb are more or less a right-off in the UK, for a 3.6kW system, to ensure you have sufficient storage capacity for the sunniest days you'd probably need 7.5 to 10 kWh of battery, plus some demand you can shift to the hours of darkness, or a car that can take a partial top-up during the day.

It would gall me to have a battery bank sitting there and no be able to flick an isolator and use it during a power-cut, looks like there's only one brand of G98 approved "hybrid" inverters that can stash some energy in a battery and run in either on-grid or off-grid mode ... inverter not that much more expensive, but battery packs push the price up considerably.

[Theo]

Yes, if you're overspeccing there's not much point unless you can use it locally.

That's a good point. I wonder if you can do the mechanicals and leave an MCS installer to wire the electrical side - presumably if the panels are part of a new roof then the roofers will install them? Is there an equivalent first fix/second fix boundary?

There's quite a few brands available - see the 'storage' section:

some aren't cheap.

Theo