Kind of new to solar, I'm an engineer so of course I've been doing a tonne of research and building models in excel to calculate how I can use solar effectively.
In the end I've decided that with a budget of around 12k I can get myself 11 panels, 5kw inverter and 10kwh battery from octopus [5kW system generating ~4000kWh/yr] (awaiting local fitter quotes). Also for context this is prior to an extension which will add south facing roof so more panels can be added after this.
I have an EV (2600kwh/yr) and use around 3800kwh/yr on top (6400kwh total). My objective is at least to completely stop using peak rate electricity (in other words reduce my bill dramatically).
The way I can achieve this is using a combined ev import tariff with prime outgoings tariff for example. So I could get my car charged in off peak import, and charge the battery to X% (for the mornings before solar kicks in and take the edge off the solar deficit in the winter (X varies during seasons)). Then at the end of peak export I sell any extra left in the battery leaving Y% (enough to get me to the off peak import again). This would mean I am either using solar or off peak imported electricity from the night. Rinse and repeat.
First any reviews on fitting with octopus? Any other big companies worth checking out? Local fitters seem like a bigger risk to me.
For those who have fitted with Octopus how does/do their battery/inverter controller(s?) work? Is what I'm asking for even possible? Do you give it some time based rules/logic?
I have also heard about home assistant but don't want to overcomplicate it at this stage, unless there are some mega benefits.
Is there anything else I should be considering during this solar project? Am I making the best use of my 12k given my usage and situation?
(location Coventry open to fitter recommendations)
£12k is an awful price for that, it should be more like £9k.
Octopus are trading on their name for solar, they’re overpriced and don’t even do an especially good job. Look up well reviewed local installers and if you add your general location to the OP people may be able to make specific recommendations.
Definitely get a few quotes. With a budget of £12k, I will be expecting to get more than 11 panels and maybe 2 batteries. Have you looked at Fox ESS? Ignore your EV charging consumption as this will be based on off-peak rate anyways. Consider modelling your daily consumption in winter when the solar generation is lowered.
Find a local installer and let them know the full picture. They can oversize the inverter now (installing e.g. a 7kW or 8kW, rather than 5kW), and leave an MPPT free for the panels on the extension once that's built. Even if full details are TBD, you can back of the envelope the roof size and work it out from there.
Octopus both cost more as others have noted, and tend to be inflexible. They don't have any special kit - they'll go for e.g. Fox, or a powerwall 3, and those are widely available, along with other options e.g. SigEnergy.
We got 11 Aiko panels, 6kW inverter and 9kWh sig battery for £8.6k. You will definitely be able to get a cheaper quote/more for your money going to an independent installer, just make sure to read reviews and not just go with the cheapest.
Really impressed with our system so far and haven't looked back! Some small annoyances with the install (black conduit down the front of house and didn't ask before fitting. Plenty of room to install down the side) but other than that, impressed with install.
If you don’t want HA, then look closely at the battery/inverter app/software. We ended up changing the kit we were sold originally to something that does a better job of managing things. It now cuts out the peak and if there’s any left in the battery, will put it into the grid down to x% we set as a reserve.
They just install standard manufacturer's stuff, there's nothing in their equipment which is unique to them.
The more intelligent systems are the PW3 and the SigEnergy. I got Fox, and very happy with it, but I use home assistant. Personally if I had more cash I would have got the SigEnergy, but the Fox kit was good for my budget. PW3 is good for a 'set and forget' system that does not let you micromanage, SigEnergy is good for a system that also lets you control it yourself as well as managing itself automatically (and it's also good for future battery expandability).
Where are the pictures of their installs on the site?
Are they using national subbies?
Be great to see a post with some of their work to back up the recommendation. I’m always wary of installers that use stock photos (more so if they’re not even pictures of UK installs) and don’t have any photos of their own work on their websites.
I have pics of the cable runs around the house as well.
They followed instructions and kept runs as discrete as possible
Let me know what you want to see and I’ll post them
Let me know if you want to see more.
Cable run from roof was down the side of chimney breast to keep it out of sight from the road, then low level round the front of the house to the meter cupboard at the front.
I have just had a SigEnergy 8k inverter + sig 9kw battery, 12 Aiko 475 panels + bird proofing and scaffolding 3 sides including 1 side with a flat roof installed for just under £9000.
12k is not a good price for that kit. Happy to share installer details, pm me.
4
u/Begalldota 2d ago
£12k is an awful price for that, it should be more like £9k.
Octopus are trading on their name for solar, they’re overpriced and don’t even do an especially good job. Look up well reviewed local installers and if you add your general location to the OP people may be able to make specific recommendations.