I am not saying i dont understand it lol. I am saying having looked at various sites, i see people quoting they have got a few quid back from solar, etc, but they hardly every take off what it cost them each night to charge the batteries.
Thats all.
27 kWh should be enough for even the darkest days in December/January (unless you have an ASHP; I can’t remember if you do).
We are now in the fourth year of our 16-panel system (with microinverters) and two 9.5 kWh batteries. Initially, we had just one, but many days in winter, we ran out. Fortunately, my installer (who was very good) owed me a favour. He installed a second battery for about 25% of the cost of the first—long story…
Like most, we charge the batteries at night and effectively run the house on cheap-rate electricity when the sun is not out. And, of course, we export any excess. Our EV is not charged by excess solar, even though our neighbors keep telling me that’s the point of solar panels and an EV. I did explain the numbers, but…
2 Likes
Great answer !
What’s your battery set up and tariff ? Octopus Go ?
I guess that’s pretty normal Internet behaviour. Brag about the good stuff but fail to mention the bad.
It’s Intelligent Octopus Go.
the standing charge is £0.48 daily. From 23:30 until 05:30 it is £0.05 per KWH. Otherwise it is £0.28 per KWH. Export is £0.12 per KWH.
When I set my car to charge it sets the times and it costs £0.05 per KWH for up to 6 hours a day. If it decides to charge during the day then any other electricity used is at the same rate.
2 Likes
I will need to sort something out, is this the best one to go to right now?
2 x 11kw batteries and ev.
About 8 kw in solar panels.
Just looked and the rates have changed a bit.
My new Octopus Go (5 hours cheap overnight) rates are 5p/28.5p with a standing charge of 47p. A battery the same size as yours is all we’re looking for at present. I’m still searching for the simplest solution !
I approximated, it’s actually 5.2p, 27.87p and 47.71p (standing).
My IOG rates are 3.5p/26.38p per kWh and 58.21p standing charge (region dependent), fixed for 12 months. However, I switched at the right time (Feb 2026). New customers unfortunately won’t get such good rates. Check with Octopus and E.ON. Note that the export rate is 12p with Octopus and 6p with E.ON for those on their EV tariff.
New customers won’t get anything right now. Octopus have suspended all variable tariffs due to price instability caused by the Iran war. They say it’s temporary but give no indication of how long it may last.
Yes they are now. I can’t speak for eight and ten tears ago as chemistry and BMS tech has improved significantly in that time. Yes batteries as with all batteries have an operational lifetime, and during thier lifetime they are designed to be and are are fit and forget.
Many batteries come with 10 or 12 year warranties where at least 70% of the capacity is available after that time with unlimited cycling.
A good installer should advise you to expect to replace and recycle your battery after 12 to 15 years.
What does that mean Chris. I have a variable rate tariff (E7) from Octopus that they are offering and selling me, and I see flexible tariffs for April are available on their tariffs selection portal as of this morning. (Agile, Tracker etc)
Are you referring to certain specific smart tariffs?
I see Givenergy has gone into administration, hope forum folks are not customers as it looks like warranties will be voided
Certainly they are only offering fixed rates for new Intelligent Go customers at the moment, with off peak at 8p. Existing variable customers, such as yours truly, can carry on with their flexible rate or switch to a fixed rate.
1 Like
Bugger. Its been on the cards for a while now. A number of the usual indicators, poor customer service, staff turnover, software “ issues”. Ive resisted updating my firmware on batteries and inverter as it works for me. Been iver a year now with no issues. ( touches wood)
I believe Flux and Intelligent Flux have been paused for new customers too.
Givenergy installs should be backed by an industry-wide insurance if MCS certified I believe. I’m not sure what that might cover though.
Hope all goes well for you. It popped up on the Sigenergy forum, a number of installers said they dropped the company as the installs always needed a call to them to overcome software issues. Hopefully they get bought out and turned round.
1 Like
Very neat Gary. The modular setup gives you a lot of future flexibility. IIRC, you can fit an EV charger module too ?