@bash for me solar is a guaranteed payback, irrelevant of export.  Increasing demand with the heat pump, just increases solar self consumption and makes it payback faster.

Posted by: @toodles

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But wait a mo… why not extend that tariff to allow those with storage elsewhere around their home or garden rather than exclusively those storage system supported by 4 wheels? Toodles.

 🤨

 That´s how we use it. Like @bash , I think wind will provide plenty of leccy to go around overnight and the utilities will not have any reason to drop those rates or ration them to only be used by EV. Of course it is a leap of faith, but all decisions are to some extent.. 🙂 

Posted by: @scalextrix

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@bash for me solar is a guaranteed payback, irrelevant of export.  Increasing demand with the heat pump, just increases solar self consumption and makes it payback faster.

That does not make sense..

I am curious about how much you export and at what rate?

And the same for imports. Unless I am missing out on and there´s some way to store 1,500kwh of leccy under my bed for the cold period, when PV production plummets. 🤣 

@batpred The 4 kW output may not amount to that many kWh’s in a day though. Suppose you were lucky enough to have perhaps 2-3 hours each day when that peak rate might be realised and another 5-6 hours at half or less of that figure. Back of an envelope scribbling might indicate perhaps 24 kWh’s each day (in the height of summer but less for perhaps 6 months of the year) Would those guesstimates suggest that you would have an abundance for more than a few months each year? Perhaps I am a little jaundiced about production figures; we have an 8.1 kWp array but this is not ideally orientated and does suffer some shading at lower sun angles - last year we produced 7.1 MWh’s and that was our best year yet. Regards, Toodles.

@toodles 

On some of the so called EV tariffs, you don't need an EV to sign up (including the one I'm on).

@toodles im on Good Energy's EV tariff. its about the last that doesnt require and EV. hopefully it doesnt get cancelled.

@toodles 

This is where I'm coming from Toodles.

7.1mwh's equates to less than £500 at an overnight rate.

We buy all our electricity at that rate.

An 8.1kw array must be the best part of 20 panels.

Octopus quoted me £7650 to install a 10 panel array.

@ £500 a year would take a very long time to recoup if ever.

@batpred I think we must be having different conversations.  I self consumed ~50% of my annual solar generation before the heat pump.

Based on the 8p/kWh LCOE of my array and it's initial cost, it would pay for itself in less than the warranty period, simply via electricity import avoidance.

Adding a heat pump, increases self consumption, which will improve the payback on the solar array. 

Payments for export are just gravy, they obviously do improve the payback, but they are not required.

@bash And there again, at least one supplier promotes and sells heat pumps and offers a very cheap heat pump tariff to go with it. Err… hold on…um, well they did, for a while.

Re: Swapping to another provider to get the EV tariff ……… out of the frying pan into the fire?!

@toodles 

Not really. I've been on an EV tariff for over 5 years without an EV. Only with Octopus and EON. No swapping required, other than moving to EON to get the 7 hours off peak they offered.

Hopefully this will continue, although with the EV rollout it won't be long before most people will have an EV anyway.

@scalextrix Yes, I have (just notionally) looked at the initial projected ROI for PV, then looked again (several times) as the energy price increases, and the ROI for self-consumption could be thought to be improving all the time! Toodles😉

Posted by: @scalextrix

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@batpred I think we must be having different conversations.  I self consumed ~50% of my annual solar generation before the heat pump.

Based on the 8p/kWh LCOE of my array and it's initial cost, it would pay for itself in less than the warranty period, simply via electricity import avoidance.

Adding a heat pump, increases self consumption, which will improve the payback on the solar array. 

Payments for export are just gravy, they obviously do improve the payback, but they are not required.

Thanks for clarifying it. Clearly there are always many factors to consider, but if your LCOE is 8p, that is still higher than the 7.5p overnight no hassle rate. 

Half our electricity consumption is currently related to the EV, but this could go up or down.

I also see the export as gravy, with the rate of return something like 2+ times the rate of return on the consumption now sourced from the overnight rate.. in real terms, my electricity bill is getting dangerously close to 0.