For help, advice and discussion about stuff not related to aviation. Play nice: no religion, no politics and no axe grinding please.
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#1908334
rikur_ wrote:
> SafetyThird wrote:
> > My system will be a LuxPower Squirrel Pod inverter and 4 x Pylontech US3000C
> > batteries. Everything is modular and I can change out individual items if
> > something should fail, which is different to, for example, a Tesla
> > Powerwall where, should it fail, the whole thing needs changing out.
>
> That sounds like what I'm looking for.
> I will pop over to Camelot to learn more, but lazy question first .... can that be
> installed outside, or does it need to be inside? An attraction of the Powerwall was
> that it could be installed outside.

Just put the order in for my setup. £6200 for the equipment then installation on top of that.

Not sure about exterior installation, some systems can but mine is going in the house.
#1976502
Doesn't seem to have been mentioned here already, but have a look at the Octopus Flux tariff.
They've also recently announced an 'Intelligent Flux' tariff similar to the Intelligent EV tariff, but that's only compatible with the brands of battery/inverter they currently install themselves, as far as I can tell.

My parents have 4.1kwp solar only, no battery. They had issues around lead time & cost when their system was quoted early this year. So you should be able to get much better figures with a solar + battery install.
Typically see a maximum generation of about 30kwh on the best days.

Bearing in mind July weather hasn't been great for solar generation, here's their figures for last month (Eastern England regional rates):

Import:
49.9kwh @ 18.43p (02:00-05:00, designed for topping up battery)
284.4kwh @ 30.72p (05:00-16:00,19:00-02:00)
43.7kwh @ 43.01p (16:00-19:00, designed for running from battery & discharging excess to grid)
42.01p daily standing charge
Total = £128.38

Export:
0kwh @ 7.43p (02:00-05:00, you shouldn't be exporting at cheap rate)
235.9kwh @ 19.72p (05:00-16:00,19:00-02:00)
36.6kwh @ 32.01p (16:00-19:00, with a battery you should be able to export more here)
Total = -£58.23

Import (incl SC)-Export : £70.15
Total solar generation 558kwh - 272.5kwh total export = 285.5kwh self use of solar - saving approx £87.13 off additional import based on average rate of 30.52p
Estimated cost without solar = £215.51, so including export rebate saving approx £145.36 (saving £204.89 in June, £179.13 in May when I started monitoring)
#1981421
Decades ago I saw a tomorrows world where a house was built with a large water tank. The water was heated up during the summer and the heat recovered during winter. Soooooo——- Use the excess pv kw in summer to heat up your garden subsoil and recover it in winter from your ground source heat pump?
#1981428
I thought I'd return to this thread that I started a year or so ago. We did go ahead with the installation but didn't get an electric car. When Octopus flux came out we started discharging and charging the battery from the grid at appropriate times.

I've just been looking at the energy bills since we had the Solar Panels and battery installed at the end of June 2022.

It is slightly complicated because it took ages to get any money back for what we fed into the grid as we failed miserably to get British Gas to install a smart meter in a timely fashion. Then we changed to Octopus who were much more helpful. Then a change in tariff to Octopus Flux and various changes to fuel prices etc. and of course some credit from the government. Then the Inverter developed a fault and wouldn't export for most of a month (replaced under warranty, but still a bit of a nuisance).

So all I am going to do is post the energy costs since we started on a feed in tariff.

In the year ending 11/09/2023 we paid nothing for electricity and we have a received a credit of £370.

Our gas has cost us £980.

so total energy bills for the year have been £610

(1930s 4 Bedroom house with only 2 OAPs living in it, gas cooking and heating but we were a bit stingy with the heating last winter).

Hope that is helpful.
#1981435
We're two months in. We already had the smart meter, but it took 3 weeks to get the export MPAN/ tariff enabled with Octopus so that we earn 15p on each kWh exported.
In those 2 months: 800kWh generated; 360 exported, 440 used;
Ordinarily that would be 360 x £0.15 = £54 earnt* and 440 x £0.29 = £128 saved.
During that time it has provided 62% of our consumption.
* Due to the 3 week wait for the export MPAN, actual was 194 x £0.15 = £29
#1981453
Dodo wrote:I thought I'd return to this thread that I started a year or so ago. We did go ahead with the installation but didn't get an electric car. When Octopus flux came out we started discharging and charging the battery from the grid at appropriate times.

I've just been looking at the energy bills since we had the Solar Panels and battery installed at the end of June 2022.

It is slightly complicated because it took ages to get any money back for what we fed into the grid as we failed miserably to get British Gas to install a smart meter in a timely fashion. Then we changed to Octopus who were much more helpful. Then a change in tariff to Octopus Flux and various changes to fuel prices etc. and of course some credit from the government. Then the Inverter developed a fault and wouldn't export for most of a month (replaced under warranty, but still a bit of a nuisance).

So all I am going to do is post the energy costs since we started on a feed in tariff.

In the year ending 11/09/2023 we paid nothing for electricity and we have a received a credit of £370.

Our gas has cost us £980.

so total energy bills for the year have been £610

(1930s 4 Bedroom house with only 2 OAPs living in it, gas cooking and heating but we were a bit stingy with the heating last winter).

Hope that is helpful.


interesting but in effect meaningless without knowing the total cost of the installation which I'd imagine you'd prefer to keep to yourself.

As an alternative would you be willing to venture how many years before the installation costs have paid for themselves and when are serious replacements due wear and tear likely to be required?#
#1981456
PeteSpencer wrote:interesting but in effect meaningless without knowing the total cost of the installation which I'd imagine you'd prefer to keep to yourself.

Ours was £7k all in for 4.1kW system, including passive provision for batteries, but no batteries.
Cheapest quote for comparable spec was £5.8k - but I wanted to go with someone with multiple local recommendations.

I've modelled payback time, but it's glorified guesswork without knowing future electricity prices.
The standard model for our location is that I should get 3560kWh of annual generation.
The standard model assumes I will use 49% and export 51%
The standard model assumes that both import and export rates will rise by 6% per annum from current values of 29p/15p.
That gives me a payback of around 7.5 years*

My personal view is that it is likely overstating the cost of electricity; we know it is coming down to 27p/kwh in October. An alternative view of the model assuming a flat average of 25p/kwh import and 10p export, and that I'm likely to use > 60%, not the 49% assumed gives a 10 year payback*. If I buy an electric car, then I might be able to push consumption to 75%, and get payback down to 9 years*.

* both ignoring any costs of repairs or maintenance.

In summary, I don't think you would do it for financial reasons alone.
#1981457
Dodo wrote:Sorry Pete, I thought it was in my original post but it wasn't.
£15K cost in 2022. 14.2kWh battery, 15 panels, max 6KW inverter.
I reckon it will pay for itself in about 7 years or less assuming everything keeps working.


Thanks v much :

I think I’ve left it too late ……. :lol:
Flyin'Dutch', Dodo liked this
#1981481
Forgive me for digressing from batteries, in favour of not starting a new thread.

Simply how does a solar system work?

How is whether panel generated power is fed to the grid, or used in the home determined? Is there an automated system based on the load? If so, if, say, an oven was switched on when there was no generation from the panels and they subsequently stated generating, would the supply to the oven switch from the grid to the panels?

Also, is my understanding that payments are for 100% of what is generated by the panels, irrespective of the percentage used by the household correct?

I have 21 panels and feel I should make an effort to use them efficiently. :oops:
#1981484
Easy one first - yes if you have a Feed In Tariff (FIT) payments they pay for all power generated regardless of where it is used.

The Invertor is able to phase lead the grid by a variable amount such that it is always a source of power , rather than a sink of power therefore any load you place on your home supply will be consuming all locally generated phase leading power.

Its actually not as simple as that but it is not, as some think, determined by your invertor providing more voltage than the grid.

https://www.quora.com/How-does-my-house-know-how-to-use-electricity-from-my-solar-panel-first-before-drawing-any-power-from-the-grid-Similarly-how-does-it-know-that-it-has-to-use-power-from-my-battery-before-the-grid-power
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