8 kW Solar + 11 kWh Battery + Ohme EV + Immersion Heater + Intelligent Octopus

cgwhite

Standard Member
Joined
Dec 14, 2022
Messages
43
Reaction score
25
Points
12
Location
Thetford
Driving
Thought I might share with you our setup which now is paying us up to £30 per month:

The key to all of this is the differential between Octopus Intelligent Go and SEG payments from Octopus, (or any other provider). 7p inbound against 15p export with Octopus. You need to ensure that you export all of your Solar at 15p and have enough battery capacity to store electricity at 7p. Overnight you have to charge the EV and topup the batteries as well as heating your hot water with the immersion heater during to Off Peak time slot, which is very generous 11.30 - 5.30 all at 7p. During the day, and up to the 11.30 off peak period, the batteries will cover your background usage, fridge, computers, etc. All of your Solar is then exported at 15p. The Intelligent Octopus with the Ohme charger can sometimes charge outside of the Peak period but is always just costing you the 7p rate regardless of the time. The secret is having enough battery storage to cover your daytime usage and to ensure that you don't use any peak kW.

With our setup of 8 kW solar and 11kWh battery storage, we have been able to tune the system to end up with a net income from Octopus during the summer months. During the winter it nets off the cost so that over the year we are virtually zero cost for electricity. When you consider that the majority of consumers are now paying up to £1700 per year for electricity it makes the £11k investment 3 years ago realistic.

One of the good points about SEG is that you can move providers as their rates change, you normally only have to give them 30 days notice and normally they will release you early as it costs them money to keep you on board.

Enjoy, shame about the Climate Change / Global Warming weather this June!

Regards,
Chris. Qualified Solar Installer. MG5 LR 2022.
 
Last edited by a moderator:
With our setup of 8 kW solar and 11kWh battery storage, we have been able to tune the system to end up with a net income from Octopus during the summer months. During the winter it nets off the cost so that over the year we are virtually zero cost for electricity. When you consider that the majority of consumers are now paying up to £1700 per year for electricity it makes the £11k investment 3 years ago realistic.
You're living the dream!
 
My latest bill still shows a bit of peak usage.
IOG and Givenergy 9.5kWh battery.

Screenshot_20240702_103151_Drive.jpg
 
Interesting, we've recently moved and have the about perfect roof for solar. Hopefully in a few weeks we'll have 8.8KW of solar and a 10KWh battery system.
Thankfully the house already had a 7KW wall box.
We switched to Octopus Go tariff, that itself has halved our electricity bill.
The solar should produce this annually.
2024-07-25 12_25_45-Solar proposal - jonathan.evans99@gmail.com - Gmail — Mozilla Firefox.png


Have you got a timer for the immersion? We have oil fired heating/hot water so looking to use the immersion heater as much as possible!
 
I've just had a conversation about this in the thread entitled "Octopus Intelligent Go works like a dream" in the MG4 forum. Worth a look, I learned a lot.
 
Have you got a timer for the immersion? We have oil fired heating/hot water so looking to use the immersion heater as much as possible!
I got the Tesla (UK) smart immersion with a timer and various settings and an app to control it remotely.

Cheaper than an Eddi but it doesn't read the solar and it can't ramp up and down.

I'd be very happy with my choice to save some money, except I discovered the immersion size I bought wouldn't be compatible with the new style of hot water cylinders. You need one of these cylinders if you get a heat pump, which I would like to do because it is a huge carbon emission saving compared to our 30+ year old gas boiler. D'oh!
 
the one thing we can't do it fit a Heat pump. Most of the house has microbore pipe and surprisingly Mrs Walks with Enzo isn't keen on the house being smashed to bits to replace it all :ROFLMAO:
 
the one thing we can't do it fit a Heat pump. Most of the house has microbore pipe and surprisingly Mrs Walks with Enzo isn't keen on the house being smashed to bits to replace it all :ROFLMAO:
That's a shame. Though it might be worth investigating, because it might just be microbore for the last little length. Guess you might not know for sure without getting floorboards up!

We've got microbore but on further investigation it was only micro for a couple of radiators with the rest medium sized, so the house would probably be ok for a heat pump with minor alterations.

We discussed the possibility of moving house in a few years, though, which makes expensive improvements seem like less of a good idea. But I am still wondering if we take the hit and do it for carbon reduction reasons.

I'm now trustee of a climate action charity so should probably walk the walk!
 
the one thing we can't do it fit a Heat pump. Most of the house has microbore pipe and surprisingly Mrs Walks with Enzo isn't keen on the house being smashed to bits to replace it all :ROFLMAO:
I like to think they would know how to put things back together!

But I think it can take a couple of days, during which you might have to vacate the house (or nearly do so).

Quite a bit of upheaval in the short term.

All needs doing at some point, so hopefully people will get it done when their boiler is on its way out.
 
That's the snag for me. My boiler was on the way out in 2019, and the desirability of doing this had not been publicised. I knew my next car would almost certainly be an EV because that had been well telegraphed, but nobody was telling homeowners to think heat pump back then. So I got a new boiler. Then in 2023 I had to have a new oil tank. Not replacing these in a hurry now, thank you.
 
Similar thing here, the boiler was replaced just before we moved here, so we have a nice efficient oil combo boiler (no chance of an Eddi here), new tank a couple of years ago plus all our radiators are finned doubles already. Our oil price is currently around 59p so a heat pump sounds an expensive option.
 
Where are you getting oil at that price? Maybe I need to shop around!
We have a local oil club that negotiate a price with local suppliers, they tend to deliver in 5-10 days, as they arrange the delivery at the most cost effective way which results in a small saving over the normal price. They don't do a top-up arrangement so you have to keep an eye on the tank and the normal minimum order is 500l.
 
57.45 pence per litre plus VAT in my part of the world at the moment.
 
I paid 91.16p last month, including VAT. There is a village oil club but the previous owners of the house were with my present outfit because they had a sort of ET phone home thing that monitored the tank and they filled it according to the readings from that. Then then discontinued that and switched to a system where they simply turn up when they feel like it, seems to be about every two months for me. I saw their tanker in the village today but they didn't come to me because I was filled up only a month ago.

I had always had the impression that the prices weren't that different between the different suppliers around here and it wasn't worth the hassle of comparing prices just for a marginal saving. But 57p versus 91p is bloody huge.
 
I had always had the impression that the prices weren't that different between the different suppliers around here and it wasn't worth the hassle of comparing prices just for a marginal saving. But 57p versus 91p is bloody huge.
I guess its a location thing, the oil club is normally the cheapest but only by 1p or so. Recently the price has been pretty stable but in the last 8 years it has gone from around 29p down to 20 briefly and as high as 80.
 
Weird. You'd think, being in Scotland and so near to where the oil is produced, and a refinery less than 30 miles away, we'd be OK. Oh, wait...

I have happy memories of prices around 56p. They're long gone. 20p? Don't make me laugh. I'd be pretty happy with 80p right now.
 
A lot of the local villages don't have mains gas (despite there being a sodding great main at the edge of our property) so there's a big market. The 20p was for a few weeks during one of the lockdowns, then it shot back up to around 25p!
 
Support us by becoming a Premium Member

Latest MG EVs video

MG Hybrid+ EVs OVER-REVVING & more owner feedback
Subscribe to our YouTube channel
Back
Top Bottom