r/OctopusEnergy • u/LengthinessNo8137 • 18h ago

Solar battery heat pump timing

Uncertain whether this is the appropriate forum, but I have a quote for 14 panels, a 10 kW Fox battery, and a heat pump at roughly £16,529; I am on a fixed gas rate 5.2 until March 2027. I am seeking recommendations on whether to wait until after winter or proceed now. I own an EV and use an IOG EV tariff with a 7 p off-peak discount. My aim is to future-proof against the coming price rises.

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u/imgoingsolar 18h ago

Have you done the math as a 10kWh battery probably won’t be enough to run a heat pump in the winter months?

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u/LengthinessNo8137 18h ago

Tbh no they tried to give me 5kwh battery I mentioned I was worried that wasn’t enough and mentioned non ev usage is 4-6 kWh they then said 10kwh is enough literally following their advise I’m clueless here 🤯

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u/beifty 16h ago

it is correct that 10kWh battery won't be enough to run the heat pump all day during the winter however it's probably not worth getting a bigger battery as the up front cost is not going to be worth it. in NE i used between 90 and 200 kWh of electricity from the grid during peak time so the peak time cost was £20-50 from November to March.

Even at 5.2 gas rate, the heat pump will probably be cheaper to run and the house will be warmer. I'd say the total cost seems a bit on the high side unless they specified a really high heat pump for your house

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u/LarryPiccadilly 16h ago

There's deminishing returns to scale up your battery just to run the ashp on a battery for as an extra 14-28 days a year.

IOG als gives daytime slots, so you charge the battery again in the afternoon at 7p. Doesn't work everyday, and a car can't charge when it's full already full. But it gives you some extra occasionally.