Hardware · Cost note
Growatt fitted cost in the UK
Updated
Fitted illustrations can start lower than premium brands, sometimes around £4,000 to £7,000 for a mid-size system, and a low price that omits the board, the application and the monitoring setup is not comparable. Price-sensitive new systems with an installer who will still answer the phone.
What the illustration includes
Growatt hybrids and battery stacks are widely available and often keenly priced. They are a volume product, which means the installer and the UK support route matter as much as the datasheet.
Get the UK warranty route in writing. A global brand name is not the same as a local spares desk.
A September 2026 figure for Growatt
Take a 10 kWh pack, cycled about 260 times, at 90% round trip. Charge at 7.0p, and value what comes back at 26.0p. Export given up is priced at 4.0p. There are no panels beside this 10 kWh pack, so every unit charged comes off the grid. Delivered energy is about 1170 kWh. After charging cost and lost export, the figure saves about £213 a year. Set that against £3,650 fitted, which is a September 2026 illustration at the temporary 0% residential rate, not a quote. That is a simple payback of about 17.1 years, which is past a typical 10-year warranty. Nudge the night rate up by 4p and see if you still like it.
In most single-phase houses in Britain, 3.6 kW is in the band where G98 connect-and-notify is often enough. Export can still be capped. Agree that before the inverter is ordered. The figure uses 10 kWh and 0 kWp, which is enough to tell two quotes apart if they assumed something else.
At a steady 600 W evening load, 10 kWh lasts about 16.7 hours. A 3 kW kettle only works if the inverter can deliver it. Capacity on the badge does not answer that.
VAT, paperwork, refusal
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 £3,650 on that basis. It does not apply to a shop, and it does not apply to a battery you buy and fit yourself.
I would not compare a £3,650 headline with another until usable kWh and the fate of any existing inverter match.
Ask the installer for the last Growatt they commissioned: postcode area, inverter size, and whether G99 was required. A first-ever install of this range is a risk you can choose not to fund.
Common questions
Is the price on this page a quote?
No. £3,650 is a September 2026 illustration for a 10 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 10 kWh example the inverter is 3.6 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 £3,650 job, that folder is part of what you bought.
What if the cheap rate is not 7p?
Then the figure changes. This page used 7.0p 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.