[Closed] Those of you with solar PV

Oh and another thing a couple of the local sounding installers have turned out to be nothing more than front websites for large multinationals using subbies.....

Is there any kind of accreditation system for solar installers where I can go to find bona fide local installers ?

I went with a recommendation from a colleague. They did a good job; everything happened the day it was supposed to, the scaffolding was 100% compliant (better than I've ever seen on major construction sites, wiring all neatly done and documented. They went into liquidation a year or two later, but it's worked for 9 years without any issues.

Things may have changed, but I'd be looking at the life of the panels, and the percentage of nominal power at end of life. Ours are something like 95% at 20 years. See if you can get a manufacturer warranty rather than the installer.

I see dual function inverters are now a thing. Ours are grid tied, so if the grid connection goes off, they shut down (to avoid electrocuting the grid repair team). Dual function would isolate and switch to supplying backup power.

Dual function would isolate and switch to supplying backup power.

Not seen that mentioned ... Going to assume that's many spends more than I've been quoted for so far......but that would be handy being at the end of a country overhead line....

Might be worth giving Local Energy Scotland a buzz, they'll know reputable suppliers/installers and can check if there's anything grant wise, etc. that might be useful.

I'm looking at this myself. Would like to get integrated panels, partly out of vanity... Well, they do just look better and new build houses going up nearby have them. I've a couple of recommended suppliers to call when I get round to it.

Voltair Energy and Logan Installations, which both came recommended by the producer (Viridian). I'm stating from a blank canvas of technical knowledge, so know nothing about inverters you speak of.

Think about adding solar thermal to the mix. That's a real investment.

Also, I sacked off all the grants and negotiated a deal with the installer and saved even more.

Solar thermal won't work I ain't got a tank.

I hadn't considered grants as my experiance is that those accredited installers working on the grants(when it was boiler replacement time) rip the arse out of it.

Would rather have a local installer

Correct about the grants.

If you had a thermal store the solar is excellent. All my hot water comes from one panel for the most of summer and the water never goes below 35 deg all year (winter I use a wood boiler stove) . I had my gas bill down to £5 a month at one point.

Interested in what you pay if you get it installed; I really like the idea of solar PV but despite having an absolutely perfect south-facing roof just don't see how it stacks up financially! Leccy/gas is just too cheap (at the moment) especially if you have e.g. LED bulbs etc & decent insulation.

Signed up for a local council-backed scheme (results due in soon apparently!) which is something like a group-buy for solar PV so allegedly cheaper installs, we will see though (no obligation to buy)

We are on oil.....with a combi . Which is even cheaper than gas at the moment. But hedging my bets neither of those things are long term. Seeing as how UK electricity generation planning is shit the green are blocking the things that need to happen to make it sustainable based on hopes and dreams of technology that is not yet able on a large scale. Microgeneration is a fall back.

Young child , wfh for the foreseeable.

Lekky bill tripled during lockdown.

Solar panels would cover 2/3rds of our bill right now and offer between a 6-10 year payback (based on the quotes) most of my bill appears to be .....dual monitors two laptops , radio all day every day kettle many times a day , cooking lunch all at home

Since the FIT stopped being so lucrative and more people are thinking along the lines of the numbers don't add up....prices seem to have just about halved or more.

prices seem to have just about halved or more.

If we had an EV I think it would be a lot easier to justify but I cycle to work and like you the GF is WFH for the foreseeable!

I see an ev in our life sooner than later and we have an e bike to charge. Electric heating will also likely be a thing when the boiler expires .

what sort of prices are we talking about? i was looking at 5-6k previously. but the payback was like 20 years! i just cant see how it pays to have it? (unless your off grid etc)

Between 3.5-4800 is the current spread of quotes I've had.

I've asked for more details so I can look at the kit they are using and how they plan to install......couple of lads on ladders on my roof doesn't appeal.

Payback works out at about 20 years if I'm working in the office but we are all pushing for a 2 day office going forward as wfh is working. Wfh it is about 10 years pay back

One thing to consider also is how easy it will be for you to clean or have then cleaned yearly. The drop in efficiency for a panel that has accumulated surface dirt is astonishing! If you dont clean them it's not like theyll stop working but if your payback period is 20 years and a dirty panel loses say 10 percent of its efficient then that's an extra two years on your payback.

Make sure you specify pigeon netting. Pigeons love nesting under them and they are noisy buggers!!

One thing to consider also is how easy it will be for you to clean or have then cleaned yearly. The drop in efficiency for a panel that has accumulated surface dirt is astonishing! If you dont clean them it’s not like theyll stop working but if your payback period is 20 years and a dirty panel loses say 10 percent of its efficient then that’s an extra two years on your payback.

Incredibly easy....the only thing stopping me fitting my own is the fact that i can't wire them in..... But I have not ruled it out as I do have a tame spark who can do the wiring but is not genned up to supply or willing to do the fit up on the roof.

I already have self fitted solar on my van . It provides all our power when away we dont bother with hookup. But I'm aware that the house is a much bigger asset to lose should it go Pete tong.

A colleague did a new build several years ago, admittedly in the days of decent FITs. He ran a spreadsheet (he's a bit like that!) and reckoned that a roof of pure solar PV panels feeding into a massive triple insulated immersion heater water tank was a better bet than solar thermal.

There's a couple of installer cos near us, seem to get a good rep.

If nothing else. Solar PV feeding surplus into an immersion means zero risk of flooding from a burst in the fluid side of the solar thermal.

Good point as well.
Having stayed last week in holiday accommodation which was new (recent) build with superb insulation and performance, we're now looking hard at how to improve performance of our current house. The current conclusion/ solution would seem to be a building plot and a new build.

Ill never update the eaves here I'm resigned to that.

But we stuck a new extension on the windward side which exceeds modern insulation standards with modern insulated uPVC windows and what a difference it's made throughout the whole house.

Really it's just the front of the house that standard and even in winter it gets the sun

If nothing else. Solar PV feeding surplus into an immersion means zero risk of flooding from a burst in the fluid side of the solar thermal.

I ride with two insurance bods. When I told them I'd got PV they related a long series of stories about paying out on houses burnt down by their solar panels. The panels that caused most fires are no longer on the market but you need to know that if your house is on fire on a sunny day the firebrigade will take one look at the panels and decide to let it burn. Mine run at 700V DC on a sunny day if I turn off the leccy - which you would in the event of a house fire.

On the other hand when the primary circuit on my solar thermal boiled it spat out no more than a litre into a bucket placed in anticipation of such an event. I now remove lagging from a pipe run before going away in Summer. It takes a couple of minutes.

The PV still produces 25-30% of May/August production in December. The solar thermal however is super efficient in Summer but poor in Winter. The solar thermal tank reaches about 20°C in December compared with 60°C in Summer. So six months hot water and six months pre-heating before a normal electric tank.

Edit: The insurance company weren't interested when In told them about the solar thermal, they upped the premium 60e for the PV and 20e for the wood burner. That gives you an idea of respective risks.

The problem for small operator in the fit days has always been the mgcs (micro generation certification scheme). Very paper work heavy, hence why many smaller guys are sub contractors. I don't know if this is still the case now the government scheme isn't as good but is shaped the industry from birth.

The solar thermal however is super efficient in Summer but poor in Winter. The solar thermal tank reaches about 20°C in December compared with 60°C in Summer. So six months hot water and six months pre-heating before a normal electric tank.

How does that scale to being much further north.

Not sure where you are in France but my parents near limoge at 45deg north and could heat buckets of water just by leaving them on the lawn.....

Here at 57 even in peak summer they would be lucky to raise from tap temp.

Anyway all academic as we don't have a tank nor plans to fit one as that would be an entire new heating system.

Make sure you specify pigeon netting. Pigeons love nesting under them and they are noisy buggers!!

got a lad coming round to do a site survey from a local MCS approved company .

financially makes little sense from what i can gather

but its seems a better use of money than in the bank these days - but also based on my current usage level which has gone through the roof ill probably do better out of it than the online calculators suggest. and we are in good situation for the next car being electric.

Does mean ill need a smart meter to get the SEG tarriff- oh joy

Interesting read
https://great-home.co.uk/are-solar-panels-worth-it-in-2019-how-about-solar-with-battery-storage/

Calcs are a little screwed due to energy being up and cost of install being down quite a bit.

Once you get solar panels you will want batteries.🤣

This popped up in my YouTube channel yesterday and looked really good. Not sure if there's a UK equivalent?

Best thing I bought was a solar I boost for heating my hot water tank. That's brought me the best savings. Works 9 months of the year.

@damascus you can get the Tesla Powerwall in the UK which sounds awesome, especially if you have an EV (looks a bit more professional than that set up too 🤣) cost is £8k+ though 😭

@zilog6128 yes, I've looked at them all but they are too expensive for a good payback. Batteries also reduce in performance over the 10 years.

Unless the price of batteries comes down or the price of electric goes up then its just not worth it at the moment.

I had a load of quotes a few years ago, range of prices was massive, the most expensive was a company based in Burton upon Trent that claim to be "The UK's leading solar energy provider", not only were they expensive they added every extra on they could and their payback numbers were way optimistic. A smaller company in Nottingham were a good 40%+ cheaper with a choice of German or Austrian made invertor.

Also any company that tries to sell you a "voltage optimiser" should be instantly dropped off your list, these do nothing to save energy usage in a domestic setting.

Batteries make no sense at all right now financially. Not even close.

I would like to fit a hybrid inverter as future proofing but I don't think I can without at least one battery on the system.

I do see electricity going up medium term due to the lack of preparation our nation is doing and we will be reliant on imports going forward.

I have purposefully avoided those types of hard sell suppliers Matt. They just scream gonna rip the arse out of it and probably go bust soon after and rise from the flames to avoid any warranty they may give.

Solar thermal doesn't mean a whole new heating system!
We just have our downstairs HW fed from the solar tank, with the CH feed going through it for heating the HW during the winter months.

i have a Kerosene combi boiler.

as i understand it i cannot have a hot feed to it - it specifys a pretty low feed temp.

My uncle (heating engineer) did mention that as i have a grant combi (vortex 26e )there was a kit in development although we had been drinking so i may be remembering wrong to allow me to run it in conjunction with a solar thermal tank.... but i did not see anything to back this up online when i looked

You could have the combi running into a thermal store coil or a plate heat exchanger to couple multiple systems.

Just had an email in with the results of the solar PV group buying scheme organised by the council. Didn't bother submitting any specifics regarding exact roof size so they've averaged it to 12 panels, total cost approx £3650 + £2250 if we also want a 3.1 kWh battery. Also a few optional extra costs such as bird netting or a UPS. Actually sounds pretty reasonable compared to what I was expecting so will definitely look into it further!
They are estimating the savings + earnings (with the battery option) at just under £500/year which gives a ROI of about 13-14 years (assuming status quo with respect to energy prices, etc)

You could have the combi running into a thermal store coil or a plate heat exchanger to couple multiple systems.

That's very over simplified . How would you control it efficiently for example. I have had a rake around grants site. It seems I can preheat my feed to the boiler from the tank to a specific temperature blending it with the cold feed. And it seems they have a manually(electrically) switchable valve system to allow the boiler to heat a tank. Doesn't sound great to me

That dies sound good zilog. What system of battery's they using sounds suspiciously cheap on the batteries ..... The panels seem to be par for course or slightly below normal install value c-5-1000 quid saved

@trail_rat the battery is a Growatt ML33RTA. Yeah it does sounds cheap, but I know nothing about these systems really except for the Tesla one which is obviously going to be top end. Will do some research... looks like they're 3kWh but modular so you can just add more if necessary.

damascus
Free Member

Once you get solar panels you will want batteries.🤣

This popped up in my YouTube channel yesterday and looked really good. Not sure if there’s a UK equivalent?

Best thing I bought was a solar I boost for heating my hot water tank. That’s brought me the best savings. Works 9 months of the year.

****ing hell him poking around in the live system with bare fingers and exposed terminals was giving me anxiety, not to mention the sparks falling towards his face when he connects the positive wire! 😲

@zilog6128 - That's great your council is helping with that sort of thing, exactly what they all should be doing! Whereabouts are you if you don't mind me asking?

tbh looking at the growatt batteries - that is a good deal.

@honeybadgerx I'm in Kent. The scheme is called "Solar Together", it covers a few other areas if you look at their website. Although the auction has already happened it looks like you can still sign up to take advantage of the group buy. It does seem a good deal on the face of it, but I will do some more research!

**** hell him poking around in the live system with bare fingers and exposed terminals was giving me anxiety, not to mention the sparks falling towards his face when he connects the positive wire!

It's a 24V DC battery system. Bare fingers not a particularly big deal. It's not 240V mains. Anything over 40V DC starts to need more care.

Some arcing would be expected on first connection at 24V... Could be avoided with a precharge resistor. YMMV, etc.

I'm in the Scottish Borders unfortunately, so the chances of the council up here doing something helpful are somewhere between slim and none unfortunately. Sounds a great opportunity for you though!

I'd definitely get protective wire. We had squirrels neat under ours and chew through the wires... £1000 repair bill including the scaffolding. Stupid squirrels didn't even electrocute themselves 🙁

@zilog6128 that sounds a very good deal.

My panels were free through a company called "a shade greener" I get the electric, they get the feed in tarrif.

Last time I went on their website I signed up for a newsletter about their battery systems. I suspect that batteries will be the next green revolution and gov subsidy. Its just a matter of time.

That’s very over simplified

Yeah I know, I wasn't going to draw you up a schematic, I just meant you can link these systems together and there are a couple of methods (amongst others ) available.

Yes but none of them are elegant or autonomous.

Most involve having one tap off the combi and the the rest coming from the cylinder and worse most want an invented cylinder and we ain't having one of those.

If my house was bigger but I have only 3 hot taps in the house. My showers electric.

That escalated quickly

All installers I've spoken too have steered me away from it and confirmed solar PV immersion heat store system is a red herring with a combi. It can be done but it's a bodge and a legionnaires breeding ground or involves making the tank a heating zone in its own right thus totally negating why we have a combi

All roads lead back to Tesla power wall though. Even installers who don't deal with Tesla are telling me to get a Tesla power wall for my requirements.

Having read up on the power wall it does look the tool.

So I have the local Tesla agent coming to do a survey later in the week.

Hot water diverter is certainly a red herring yes. If you heat with gas then you are making a trade off to divert free electricity to offset 3p kwh gas when you could use it in the home and offset 13p kwh electricity. If you have EV then its even better. Its better to export elec at 5.5p than use a hot water diverter. Total red herring. Also struggle with the benefit of a home battery that can store less than £1 worth of electricity but costs £3000+ never get any benefit surely.

We had what wil probably be the last totally solar thermal shower of the year yesterday. We ran through the normal tank a half a dozen time in October to top up to shower temperature and from now until March we'l only be using the solar thermal as a pre-heater and to direct feed the washing machine.

We're 43°N which is clearly an advantage but when you work it out you'd still be getting sun at the same angle as here today in late September in the UK. There's 9° latitude difference between here and Birmingham and there's 47° degrees between the tropics of cancer and capricorn

@trail_rat what does the Tesla do specifically that other (cheaper) battery solutions can’t?

Go outside

Have it's only battery cell temperature control.

An I right power wall is about:£10k?

8k if you go for the smart disconnect doodah. Which iirc is 1200 on its own

I wouldn't matter if I was on the equator to be fair solar thermal is incompatible with the existing infrastructure.

Electricity looks to be about 16p/KwH. The power wall holds about 2 quid of energy and releases it at a time when you can use it.

So that's 2 pounds a day 365 days a year * 10 years (warrenty period)

Even beyond that if it's deteriorating it'll still provide benifit.

All that's working on the premise that energy will remain as cheap. I am hedging that it won't.

So that’s 2 pounds a day 365 days a year * 10 years (warrenty period)

Only it won’t hold that in December, probably not in November or January either. So you might get £4,000 benefit from your £8,000 battery in 10 years

My panels were free through a company called “a shade greener” I get the electric, they get the feed in tarrif.

My god, I hope you never have to deal with those cowboys. They were the most horrendous company to deal with when I tried to sell my late Uncles house. And the inventor of whatever deal they managed to setup with my Uncle deserves an eternity in hell - there were mortage providers who were refusing to deal with the house because of their setup. Simple no-chain transction took almost a 9 months with them, thatnkfully the buyers were patient and so wanted the house.

Only it won’t hold that in December, probably not in November or January either. So you might get £4,000 benefit from your £8,000 battery in 10 years

Oh do they not work in winter ?

The battery works in winter but the PV won't produce enough to use the capacity. In May - July, our panels will typically produce the 12kWh/day that your calculation assumes, in Dec - Jan we'll be lucky to get 2kWh/day. You may do slightly better, our roof faces SE not S, and some of our panels are quite low so don't get sun until it rises above the houses opposite.

Fortunately my calculation is simplified

Octopus/Tesla power plan and usage learning algorithm brings even more to the party.

At 43°N my production varies from 90-120kWh for the month of December to over 400 in the sunnist months.

Given the amount of hydro pump storage in this part of the world I feel a power wall would be a waste of resources. The electricity company can do it more efficiently and more ecologically. You are only evening out your persoanl demand, the electricity company evens out everybody's demand so you may inadvertently be storing energy when the grid needs it.

You are only evening out your persoanl demand,

google the tesla power plan.

its basically decentralising the grid but with added benifits in your favour.

teslas algorithym is set up so that you store energy from the sun during the day(off peak), and feed to the grid what your not anticipated to use at peak times - and charge again in off peak at economy 7. Costs in = costs out rather than feeding in at 5.8pence and buying back at 18pence

Over head lines here mean multi day power cuts are a normal thing each winter. Power outages for an hour or so in the night are quite common when the wind gets up.

but yeah i think basing it on the cost of energy today is not a good idea in the uk. We have barely got plans in place let alone infrastructure to cope with retiring our aging infrastructure.

BE cause the vat loophole is closed and no matter what you do the 20% vat applies to the battery and install rather than the 5% a solar install attracts (pre 2019 you could get a battery installed at same time on 5% VAT ) theres no incentive to rush it and get it all together so i see a solar panel install followed by a battery- The inverter and the Powerwall/smart gubbings are seperate unlike other battery installs.

@trail_rat interesting... are Tesla (via Octopus) effectively subsidising your leccy then by offering you a cheaper rate PLUS a better rate for the power you export, provided you buy one of their Powerwalls? Have you factored that into you ROI calculation? Wonder if it makes it more attractive than e.g. me going for a cheaper battery system which doesn’t have that rate attached... looks like you can save £80+/year from no standing charge alone...

I have , but I still think that today's numbers it's very on the fence.

What it does do is push it in having a batteries favour. I couldn't make the numbers work even close based on the quotes I have with a standalone battery. (I am being quoted about 1/3rd more than your being quoted - but even then the installer recommended I should look at the Tesla stuff as it makes far more sense.....and the fact he doesn't even sell it speaks volumes to me)

My only worry is..... Tesla warrenty is 10 years - it's also unlimited charge cycles ... But will the energy plan still be around in 10 years....and further I like to keep stuff off the internet of things - it's far from a done deal that I'll have one but its attractive for sure.

Still waiting on my quote from Tesla mob - but as far as i can see it tesla work on a fixed price install (8000 for the unit and the smart box of tricks)

The thing thats gonna kill me is - panels - can only get 12 on my roof (and maintain access to dormer and chimney for maintenance )

so that puts you in 320 or 350 watt territory $$$ rather than the standard 300watt panels

Is anyone else suffering from a Lichen attack on their panels? Any ideas of what I can use to remove it that won't damage the panels - plenty of snake oil for sale online but would prefer some real life STW experience. Unfortunately the polution belching out from the woodburner chimney has not been sufficient to keep the fungi at bay.

thanks

Unfortunately the polution belching out from the woodburner chimney has not been sufficient to keep the fungi at bay

I'd expect it to have the opposite effect; soot deposits on the panels will have created a good environment for growth. Our panels were sold as 'self-cleaning' and the rain does appear to have washed them effectively (no drop in efficiency in 11 years) but I think there's a minimum slope for it to work.

I go up on the roof with a mop, brush and bucket of water with standard household cleaning fluid, it works fine. The PV panels have "self-cleaning" glass and do stay a lot cleaner than the solar thermal which has normal glass. I go up around mid-March because cleaning the solar thermal then gets the water hot enough for a shower, and agin in mid-October because cleaning it then gets another couple of weeks of hot showers.

@trail_rat - was going to post my own Solar PV / hot water thread, is there an easy to understand about how it all works? w.r.t. the battery storage especially. It's a long-term plan, don't even have PV panels or indeed a suitable house (yet). But we're working on it...

https://energysavingtrust.org.uk/advice/what-type-of-renewable-energy-is-right-for-me/

Lotta reading but generally just of it is in order of bang for buck

Insulate (walls windows doors)

Utilise Solar gain

Solar panels PV

If you have the existing capacity or need a new heating system. -multi input heatstore with system boiler and immersion solar dump.

Solar thermal - but you need the existing system. Costs less to install. But is a one trick pony.

Waaaay down the list is battery -based on current data.

Read up on the Tesla kit and the corresponding power tariff that is the only way it makes sense.

cool. cheers. Brilliant link. Ideally we'd not be relying on gas/fossil at all. Hopefully can get proper guidance not snake oil sales tactics when we go looking properly.

If your staying local to where you are. The service I've had so far from AES solar in Forres has been the best I've had.

They seemed realistic.

Yes, still local (wavered a bit recently but decided we're staying local.
Aye, I've heard good words about AES. Noted. cheers.