Hardware · Comparison
Enphase IQ Battery: should you install one?
Updated
Enphase is an AC-coupled microinverter ecosystem. The battery sits on the AC side, which makes it a coherent retrofit where the roof is already Enphase, and an expensive way to start if you do not want microinverters.
Where this kit fits
Shaded roofs, owners who want module-level monitoring, and retrofits that are already on Enphase. It is a weak buy when unshaded simple roofs where a mainstream hybrid would store the same evening energy for less.
Unshaded simple roofs where a mainstream hybrid would store the same evening energy for less.
A September 2026 figure for Enphase IQ Battery
Take a 10 kWh pack, cycled about 280 times, at 90% round trip. Charge at 13.0p, and value what comes back at 27.2p. Export given up is priced at 6.0p. There are no panels beside this 10 kWh pack, so every unit charged comes off the grid. Delivered energy is about 3402 kWh. After charging cost and lost export, the figure saves about £434 a year. Set that against £6,285 fitted, which is a September 2026 illustration at the temporary 0% residential rate, not a quote. That is a simple payback of about 14.5 years on these assumptions. Nudge the night rate up by 4p and see if you still like it.
In most single-phase houses in Britain, 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 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 £6,285 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 sign off a 10 kWh install from a video call. Someone has to open the consumer unit.
Ask the installer for the last Enphase IQ Battery 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. £6,285 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 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 £6,285 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 27.2p 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.