Solar + battery quote check please – 6.8 kWp + 10 kWh battery for £7.3k net, good deal?

tunatuna

Thanks for all the feedback so far — it’s been really helpful, but I’m still trying to understand what practical benefit I’d actually get from moving to a more premium inverter/battery brand versus sticking with the value setup I’ve been quoted.

Stepping up to brands like EcoFlow or SolarEdge seems to add at least £2–3k to the install cost, which pushes payback out by a couple of years. Since my aim is good ROI rather than a premium setup, I’m struggling to see the financial case unless reliability or savings are meaningfully better.

I’m also trying to understand how much real financial benefit people are seeing from tariffs like Octopus Intelligent Flux. After losses and real-world usage, what extra savings per year are people actually getting compared with standard export plus basic battery scheduling?

So I’d appreciate views from people with a few years’ experience:

• Are cheaper hybrid inverters and batteries (Solis, Dyness, Fox etc.) really failing after only 5–6 years, or are most systems running 10+ years without major issues?

• Is installer longevity a bigger risk than hardware failure?

• Apart from warranty and app quality, what real day-to-day benefit do premium systems give?

• And what extra annual £ benefit are people genuinely seeing from Intelligent Flux-type tariffs?

Just trying to balance sensible equipment choice with competitive ROI rather than simply buying the most premium kit available.

NedS

Intelligent Octopus Flux is a net use tariff, so if you generate more than you use (net exporter), then it pays an unbeatable rate for that export. We run it for 6 months a year (April-September) whilst we are net exporters, and last summer averaged around 26p per kWh for our export. The more you export, the more you earn. Having a large battery to export more during peak rate helps, but may be restricted by any export restriction set by your DNO. We earn enough in summer to completely offset our use in winter (including heat pump), so Octopus end up paying us each year and we have no bills. We probably would not be able to achieve this without IOF.

NedS

The biggest consideration when I chose my battery system was thermal management. I had no choice on location - it had to be located outside, on the side of the house. The primary purpose was to allow us to take full advantage of the Cosy tariff in winter to run the heat pump on cheap rate electricity, so I needed to be able to fully charge/discharge 3 times per day, even when it is -5C outside during winter nights. Having a battery that will not charge below 0C, or will only charge very slowly so cannot fully recharge during the 3h cheap rate window was of no use to me, then the importance of thermal management.

Tesla was widely accepted as being a market leader in this respect. The more DIY solutions were completely ruled out due to being unsuitable for outdoor use in cold environments at the time (I have never going to put a Fogstar battery outside, although I understand some now have water resistance and thermal management). The middle tier of batteries weren't that much cheaper than Tesla, and I didn't really like any of the cheaper options that my local trusted installer offered.

Screwdriva

https://forums.moneysavingexpert.com/discussion/comment/81884563#Comment_81884563

In my view, the PW3's cold weather performance, reliable aftersales, intuitive software + app, genuine whole house blackout protection with their Gateway and safety track record all come together to form a really well rounded offering, and is probably the best available battery inverter in the UK for single phase households.

In my anecdotal experience (following up on over two dozen PW3 G99 applications), DNO's award higher export allowances to PW3 based systems. When I met with Tesla UK, they did share they had met with all the major UK DNOs to educate them on the grid balancing merits of the PW3, which appears to have had a positive effect.

tunatuna

Great feedback thanks for taking the time to reply.

I've been in discussions with the installer today and have managed to get them to commit to an EcoFlow Power Ocean system for £8,995.

Thoughts on this? Guessing this would be compatible with the Octopus tariff mentioned?

JKenH

https://forums.moneysavingexpert.com/discussion/comment/81884838#Comment_81884838

Yes, previous enquiries to my DNO regarding adding a battery and/or more panels had received a negative response. I was somewhat surprised, therefore, when the application for a PW3 and extra 5kW of panels was approved with an 11kW export limit.

Screwdriva

https://forums.moneysavingexpert.com/discussion/comment/81884269#Comment_81884269

I only use fiscal as it has typically meant dealing with treasuries (i.e. my wallet) and my budget.

I do not have any constructive comments on Fogstar other than to say “different strokes for different folks”