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.