Places · Case file
Sigenergy SigenStor for a heat pump in Exeter
Updated
A Sigenergy SigenStor will not run a heat pump through a cold Exeter evening from 13.5 kWh. It can shift a slice of the Exeter load into a cheaper window, and that slice is the only honest sale.
Sigenergy SigenStor on a heat pump in Exeter
Devon yield is kind on a clear roof and irrelevant if the inverter choice is wrong, which is the constraint I would write next to Sigenergy SigenStor for this heat pump.
National Grid Electricity Distribution covers this Exeter example. A 4 kWp-class roof at 1040 kWh per kilowatt is about 3,120 kWh a year before shade, and Sigenergy SigenStor does not change that weather.
Money for Sigenergy SigenStor for a heat pump in Exeter
Take a 13.5 kWh pack, cycled about 260 times, at 90% round trip. Charge at 13.0p, and value what comes back at 26.0p. Export given up is priced at 4.0p. There are no panels beside this 13.5 kWh pack, so every unit charged comes off the grid. Delivered energy is about 3159 kWh. After charging cost and lost export, the figure saves about £365 a year. Set that against £6,348 fitted, which is a September 2026 illustration at the temporary 0% residential rate, not a quote. That is a simple payback of about 17.4 years, which is past a typical 10-year warranty. Nudge the night rate up by 4p and see if you still like it.
Where the job is a qualifying install in a home, the 0% rate runs to 31 March 2027 and is due to become 5% after that. This figure prices the work at £6,348 on that basis. It does not apply to a shop, and it does not apply to a battery you buy and fit yourself.
Connection for Sigenergy SigenStor for a heat pump in Exeter
In Exeter, on National Grid Electricity Distribution, 5 kW sits above the 3.68 kW G98 line, so this wants a G99 application before anyone energises it. Export can still be capped. Agree that before the inverter is ordered. The figure uses 13.5 kWh and 0 kWp, which is enough to tell two quotes apart if they assumed something else.
In Exeter, the weak case for Sigenergy SigenStor is simple: A tiny terrace that only needs 5 kWh and a simple AC retrofit beside a healthy existing inverter.
Would I proceed with Sigenergy SigenStor for a heat pump in Exeter?
I would not pay the bulk of £6,348 before the DNO route for a 5 kW inverter is known.
I would proceed on Sigenergy SigenStor for a heat pump in Exeter only after the cupboard, the 5 kW connection route and the tariff gap are written down.
Common questions
Is the price on this page a quote?
No. £6,348 is a September 2026 illustration for a 13.5 kWh example at the temporary 0% residential rate. Your survey replaces it.
Will it stay on in a power cut?
Only if a gateway or essential-load board was designed and paid for. A standard grid-tied battery turns off with the grid. On this 13.5 kWh example the inverter is 5 kW, and backup is still a separate line.
What paperwork should I keep?
Keep the MCS certificate where the job is certified, the electrical certificate, the DNO record, the schematic, the warranty registration and a photo of the schedule. For an illustrated £6,348 job, that folder is part of what you bought.
What if the cheap rate is not 7p?
Then the figure changes. This page used 13.0p as a charge rate and 26.0p as the rate avoided. A smaller gap means a worse payback. Read the live tariff.
Sources
Want a price for your house?
The figures above are a rough guide. An installer still needs to see your fuse board, where the battery will go, and whether you want power during a blackout.