8.5 kW Bifacial PV System: ~7 year ROI: Fact OR fiction?

Qyburn

https://forums.moneysavingexpert.com/discussion/comment/81377056#Comment_81377056

I suppose one concrete example is that there was no suggestion of !!!!!! low temperature performance back when Solaredge was being pushed.

Screwdriva

In those days, your best options were SolarEdge, Enphase or GivEnergy. Given the choice, I suppose I'd be grateful knowing my manufacturer was still around and didn't just file for administration. Since its launch, nothing comes close to the PW3's cold weather performance, or indeed overall performance.

Screwdriva

All time monthly & daily highs in 5/2026. I never imagined we’d come so close to 50 KWh in a single day, even when we expanded the system.

With export at 16p via Ecotricity, earnings are higher than ever without a battery (for now).

NedS

Brilliant. We've only achieved 50kWh in a single day once so far, this April.

Our next goal is a 1MWh month. We came close last month (May), but no cigar.

For reference, we have 7.2kWp installed on a south facing roof with minimal shading.

Screwdriva

That's a great result. We have a few headwinds for our property:

1. 5KW inverter is clipping during the summers, and the internal wiring prevents an upgrade to the correct sized 6KW inverter.
2. The chimney shades 1-2 panels at any time of the day
3. Triple aspects (ENE 2.7 kWp, WSW 3.3 kWp , SSE 2.4 kWp)

Given these, I should be more content with the performance.

Screwdriva

New all time daily (just missed the 50 KWh milestone) and monthly highs this month!

Qyburn

We've not had that sort of cloudless day since February this year. But even with stop start generation it's notable how much would have been clipped. Nominal 8.1kWp panels, 6kW inverter. Blue line is inverter AC output, yellow is solar generation (which isn’t metered directly by Solaredge so calculated from inverter AC output power plus battery DC power). Just realised the time axis is clipped off, this is from 10:00 to 16:00.

wakeupalarm

https://forums.moneysavingexpert.com/discussion/6077150/8-5-kw-bifacial-pv-system-7-year-roi-fact-or-fiction

It's gone over 6.5 years since install. Have you already reached ROI/breakeven point?

Screwdriva

https://forums.moneysavingexpert.com/discussion/comment/82054363#Comment_82054363

The system has generated 32+ MWh to date, so not quite yet. Looks like it will recover the original cost of the system (£7K) by the end of this year.

A system like mine (8.2KWp bifacial with SolarEdge inverter) costs ~£7K today if done in one go (unlike me, who paid to have them revisit twice to expand the system) so payback should still be possible in 7 years or less.

Screwdriva

I don't think I'll ever see a previous best record being broken like this again! Not only the best July but the best monthly generation ever! With my tariffs & consumption, that translates to ~£250 earned/ saved.