The true value of solar and battery storage

Been running my cabin setup for about three years now — Victron MultiPlus-II, 10kWh of Fogstar Drift cells, ~4kWp of panels on the roof. Numbers people bang on about payback periods make me want to throw my laptop into the nearest field.

The "true value" conversation needs splitting into two things people keep mushing together:

Actual financial return — yes, it's slow, yes, the spreadsheet looks grim if you're honest about it.

Functional value — being able to charge the EV overnight on yesterday's sunshine, not caring when Octopus sends another "we're adjusting your tariff" email, running the cabin indefinitely during grid outages. That stuff doesn't show up in a payback calculator.

My rough take after three years:

• Saved probably £1,800-ish on bills (generous estimate)
• Added genuine resilience I've actually needed twice this winter
• Stopped obsessing over unit rates, which has a genuine quality-of-life value I cannot quantify

The thing that annoys me is people treating this purely as a financial product. It's infrastructure. Nobody asks what the "payback period" on their central heating boiler is.

What's everyone else's honest assessment? Particularly interested if anyone's running a similar hybrid EV-charging setup — wondering if my generation figures are typical or if I've just got lucky with the panel orientation.

@Curly38 payback period obsession drives me mad too. It's a completely wrong framework when you're off-grid or supplementing a static caravan setup — the alternative isn't "do nothing and save money," it's diesel genny noise, fumes, and £2/litre fuel burning constantly.

My actual calculation:

• Avoided genny fuel: easily £600-800/yr
• Avoided genny servicing: £200ish
• Convenience value: genuinely priceless when you're charging an EV overnight off surplus solar

The pedantic bit though — people do need to model degradation honestly. Fogstar cells won't be 100% capacity in year 8. Build that into your thinking or you're lying to yourself.

The real value is energy independence with a known, fixed capital cost vs open-ended fuel spend. Completely different mental model to payback.

@Curly38 same setup roughly on my garden office and the narrowboat — payback calc never made sense to me either.

The bit nobody prices in properly is reliability. Grid goes down, I don't care. Bad weather week? Fogstar cells are still holding enough to run what I need. That peace of mind has actual value even if you can't stick a number on it.

Also the flexibility of where you can put a building changes completely when you're not chasing a grid connection. My garden office would've cost £4-6k just to get a supply run to it. Solar sorted that problem entirely and gave me proper capacity.

Payback period assumes the alternative costs nothing. It doesn't.

Nobody talks about the "payback period" on their central heating boiler, do they — it's just infrastructure.

My shepherds hut runs a Victron SmartSolar, Fogstar cells, and charges the EV overnight when the sun's been generous. Try putting a number on that smug satisfaction when the neighbours are moaning about their energy bills.

The real value is resilience — I've had the grid go down twice this winter and genuinely didn't notice until my mate texted asking if my power was out. That's priceless, and no spreadsheet column exists for it.