ASHP and electric tariff

[JohnMo]

16 minutes ago, Wil said:

 No external antenna that can be fitted to help it read? That was potentially an issue for us too, but harder getting a 3phase smart meter installed and then a suck-it-and-see if it works… jury still out but they let me switch…

Tried with British gas and octopus both a big fail. None of our neighbours have any luck either. 

[Wil]

Hmm bad luck. I’d been on E7 for the previous 3 years though and it has the same effect, just not as good rates as the intelligent go. If you can load shift to your 7 hours at least it’s 16p as opposed to 34 or whatever your peak is.

 

We also found in the summer, the tail of the E7 period would cover our morning routine and showers/ shoving the kids out the door by 8. (Ours was a dumb meter and was 12-7in DST and 1-8am in BST).

[JohnMo]

Just been looking at the numbers for the last couple of sunny days. 

 

Our normal consumption of electric without heating and hot water is around 17 to 18kWh at this time of year. On standard rate tariff would cost £4.50

The heat pump used 19kWh electric each day (heating electrical demand of 4W/m2), for UFH and DHW. On standard rate tariff would cost £5.13

For comparison, a CoP of 3 would make 57kWh of heat, so from gas at 0.08p and 90% efficiency, would cost £5 plus standing charges, so pretty similar to ASHP.

 

However we only imported an average per day of 24kWh at an E7 cost of £4.41 average per day. Utilisation of cheap rate rate was above 96%

The remainder coming from Solar PV and PV stored in a battery.

Total cost per day was £4.41 against a standard rate tariff, no PV or battery cost of £9.63 (17kWh for house and 19kWh to heat pump).

 

 

So two good solar days (but sub zero during the night and between 5 and 8 during the day) saves £5 per day or £10 in total, with E7, battery, and PV. Or looking at from a heating perspective I am getting my heating for free.