How much can I practically/legally DIY, and other newb questions

[sharpener]

And so my DIY journey continues... Having got the battery and inverter sorted out, I'm now investigating PV panels...

Just got a quote from a local company, to fit 10 panels, over £6k. I'm thinking that's a bit steep, for panels costing about £2k. I suspect they don't really want to do part jobs (they initially quoted about 10k for a full system).

It's not a good time of the year to get roofing work done, but I'll be looking around for someone who do the work if I buy the panels. Any opinions on what I should be expecting to pay for simply mounting 10 panels on a normal 2 storey house?

A few thoughts on this.

I have found very few companies willing to even contemplate partial installs, they can make more margin on complete systems and then have no issues with warranty liability.

Have recently been quoted 5K to install 8 panels (no inverter), which I am thinking is pretty steep as the kit can be had from e.g. Midsummer for less than half that.

AFAIR Scottish Power have a fixed web price of £5620 for 8 x 370W panels inc inverter. This seems better vfm as the supply and installation of the inverter must be worth quite a bit. The headline price doesn't say whether or not scaffolding is included, however most companies including the former people say is is extra as they have little control over the costs. However this gives them no incentive to minimise it!

If you get scaff included in the PV contract price then I think it is zero-rated, if it is a separate contract then you have to pay VAT. It cost us ?£400 + VAT for a shorter length but higher scaff to replace the barge boards on our gable end. There is a company in N Devon ?Barnstaple? fitting panels using roped access.

Different installers prefer different rail systems and fixings so you need to find the installer before buying the bits. If you have a slate roof be particularly careful they have appropriate experience.

Callidus said they could install panels from an alloy tower costing ~£120 to hire and quoted less than £5k but then backed out of the job at 24 hours' notice. Wasn't happy as I had just spent a day and many £00s installing a Victron MPPT which has not to date contributed a single kWh.

HTH

[Stinsy]

And so my DIY journey continues... Having got the battery and inverter sorted out, I'm now investigating PV panels...

Just got a quote from a local company, to fit 10 panels, over £6k. I'm thinking that's a bit steep, for panels costing about £2k. I suspect they don't really want to do part jobs (they initially quoted about 10k for a full system).

It's not a good time of the year to get roofing work done, but I'll be looking around for someone who do the work if I buy the panels. Any opinions on what I should be expecting to pay for simply mounting 10 panels on a normal 2 storey house?

If I were you I’d look for a roofer to fit the panels rather than a solar company.

A solar company will be looking to make thousands on a full install. Whereas a roofer will whack the panels up on a Saturday morning for a few hundred.

[Krill]

A friend of mine (electrician) said I could get a small scaffolding tower for £300-400 which would be enough to install PVs. I'm not planning any installation for the next couple months at least so haven't investigated it but I was also thinking about hiring some sort of lift.
Do PVs make any sense as long as we can charge for £10-15p/kwh?

If you mean, does PV make sense if you only pay 10p to 15p / kWh on a cheap rate ?

1) Import won't be as low carbon as having PV.

2) Come April and the energy cap subsidy goes bye bye, what's the cheapslot price going to rise to ?

3) You have to factor in about 25% extra on the inefficiencies of charging / discharging batteries from the grid.

4) if you put up 4kW and generate 4000kWh and use 3,500kWh, at 15p / kWh thats £525 a year. Say £4k for the install, thats about 8 years payback. Certainly over a 10% per year saving, so why not put it on a cheap credit card transfer like I have always done and it will pay for itself.

The other point, which I was asking about the other day (week?) was about the maximum amount that could be exported and nowty linked the the relevant HMRC documentation (which is actually quite iffy IMO, it just opens the door for a discussion). Doing this earlier gives time to make future changes to reduce costs (and reduced costs means less money that needs to be earnt which means less tax and NI paid on earning to buy what you want, so savings are worth more than money earnt).

If you add more and more panels and generated an excess, how much can be exported for profit? Yes, you may end up paying an income tax on it but it is possible to get around that (private pensions etc). And then what happens when you get an EV? I reckon my wife and I pay £2,000/year on fuel for vehicles which with a single EV we could reduce to below £500/year easily. And then add in an ASHP, and an unvented cylinder? I read a lot about people ttalking about shoulder months but a large enough solar array doesn't have shoulder months (at least if you don't use electric heating).

A lot depends on what it is physically possible implement, but how much would be saved per year also depends on how far one wants to push this. I reckon I could save over £4,000/year with solar PV and would look at a 5 year return (pessimistic but not taking into account different prices between EV and FF vehicles) if I don't DIY any of it, faster if I do.

Personally I don't see electricity prices going down even if they do get to break the link with gas.

[nowty]

In @ducabi case and most cases, income tax will not be even remotely a risk from a PV installation. The only way I can see this if a modest house has a 3 phase supply and a back field with a 50kw array in it with SEG or FIT contract.

Funny enough I did pick up one of my second hand growatt batteries from such a property several years ago in Essex.
The owner was getting £5k to £7k income on his FIT contract and was complaining about the size of his gas bill.

I suggested as he had a back field with a 50kW PV array in it, and a 3 phase supply, why not install a big GSHP heatpump and claim the RHI, he looked at me blankly.

[dangermouse]

If I were you I’d look for a roofer to fit the panels rather than a solar company.

A solar company will be looking to make thousands on a full install. Whereas a roofer will whack the panels up on a Saturday morning for a few hundred.

My thoughts exactly, but haven't yet found a roofer willing to take it on. I'm sure I'll find one though, but it might not be until spring, winter is not the best time to do roof work.

[ducabi]

I need to do the math again but normally we use 9-12kWh a day. Based on what I've read about ASHP it's no-go for our property. So, in order to make a good use of the panels (no FIT) I need something generating 6-8kWh a day in summer days so that not much is lost. But then it means next to 0 during winter. On the other hand 20-40% of the cost is installation which doesn't change by much when it's bigger.
One of options I'm considering is installing 2-4 panels myself on garage (attached to house), which would

I know changes to energy cap may "help" to improve payback time hence I'm not saying no, but last time i calculated it it was equivalent of around 15p/kWh (we to account for higher interest rates too.

I'm glad winter is coming so I don't have to rush it now.

Btw
@dangermouse Have you used any torque screwdriver to make sure it's all tight by the book? If so, what did you buy?

[dangermouse]

Btw
@dangermouse Have you used any torque screwdriver to make sure it's all tight by the book? If so, what did you buy?

If you're talking about the electrical connection screw terminals, nope I just "nipped it up". The electrician did check those, but again with a normal screwdriver and he seemed to be just checking nothing was loose.

[nowty]

@ducabi, I'll be frank here.

You've probably spent £6k+ on batteries and a hybrid inverter, all installed now and operating apart from your waiting for a smart meter to get onto a cheap rate tariff.

Regarding PV, all you need is a few panels and some, cable, etc to connect up to your inverter and your overthinking whether its worth it or not, whether paybacks good enough or whatever.

I've installed tons of stuff which did not seem financially worthwhile at the time, but did it anyway and its all turned out to be the best thing I ever did. My only regret is that I did it all piecemeal and ended up spending more than I needed to.

Personally I'd get as much on your roof as you can but if money is now tight, your garage sounds like an easy win, bear in mind you will need at least 3 and maybe 4 panels to work with your inverter as there is a minimum string voltage required. But it won't even be £1k to do it.

[marshman]

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[Oldgreybeard]

I've never heard anyone expressing regret at having installed too much PV, or too much battery storage, TBH. A couple of years back, when I added battery storage here I did wonder if I'd gone OTT, as I opted to install about twice the capacity I though we might need, simply because savings weren't doing anything and I felt that the money was better invested in batteries than being sat in the building society.

The combination of a fair bit of PV (installed back in early 2014) and the battery system has made an astonishing difference to our electricity consumption. During the summer we're pretty close to being off-grid for months on end, and even in the winter we get the odd day when the PV generation offsets most, if not all, of our consumption.