Another tariff query!

lohr500

Hello all. Looking for some help please :

My son is moving into a 2 bedroomed new build semi detached property at the end of June.
It will be fitted with an ASHP (make/capacity unknown, but trying to find out).
No solar panels due to proximity to Stansted Airport and an imposed planning condition.

He also has a plug in hybrid vehicle which he fully charges every other day or so. Annual consumption for this assuming a 90% charging efficiency : : +/- 2000kWh

I am trying to help him decide which electricity tariff to go for.

He can schedule things like clothes washing/drying, dishwasher, etc into any off-peak periods.

The problem I have is that I know nothing about the ASHP usage pattern, so cannot model his likely usage.


I gather it is best practice to allow an ASHP to keep the house at a constant temperature rather than treating it like a conventional boiler.

But with a well insulated DHW tank, presumably the ASHP could only heat water during cheaper periods.

Given he has the PHEV and the ability to load shift some activity into any off-peak windows, my gut feel says go for the EDF GoElectric tariff with 6.99p off-peak for 7 hours. Peak would be 30.28. .

He could maximise the 7 hours off-peak window to heat his hot water, do his washing/drying, etc and perhaps increase the house temperature by a few degrees, then step back the heating during the day and see if the temperature loss is tolerable mid winter.
In the warmer months he shouldn't need any heating so the EDF tariff makes even more sense for the summer.

The other alternative is to look at some of the Heat Pump Specific tariffs which seem to give lower rates early morning and mid afternoon. But the lower rates don't get anywhere near the 6.99p EDF EV rate and some have a premium anyway for the times outside of the lower rate windows.

Although roof top solar panels have been blocked by the planning process, he can apparently add them later (crazy system!!). Or he could put in a balcony solar kit in his south facing unobstructed garden to give a leg up to his daytime usage. Trouble is, I guess when he needs heat in the house through the winter months, solar generation will be at its lowest so he would also need a chunk of battery storage to feed the ASHP. .


Bottom line is that we just don't know what the ASHP consumption will look like and need to build some history through summer and winter.

Has anyone been in a similar situation?
If so what tariff structure did you go with initially and did you subsequently change based on your actual usage patterns?

QrizB

Not specific to your son and not my personal experience (no HP here yet), but other posters in similar positions have sometimes chosen an EV tariff for the summer months and a HP tariff for the winter ones.

lohr500

https://forums.moneysavingexpert.com/discussion/comment/81970088#Comment_81970088

Thanks @QrizB

That would make sense.

We would need to factor in any exit fees. That EDF GoElectric tariff for example has a £75 exit fee.But it is currently fixed for 12 months which might not be a bad thing given the turmoil we are seeing in the Middle East. That said, a lot could happen between now and when he takes possession at the end of June.
Some of the other EV tariffs have no exit fees but higher unit costs, so they may also be an option.