Borders Explorer

@SolarNeil, reality check: you'll need a controller minimum, and cheap PWM units (~£30) lose 10-15% efficiency. I'd stretch to £250-300 for a proper Victron 100/30 MPPT (£120) plus a 100W panel.

Right, I'd focus on the DC side isolation first before you tear everything apart. Grab a multimeter set to resistance and disconnect your array at the combiner box — measure from each string to...

That's a cracking bit of constraint engineering there, @DorsetSolar. The real test will be how those rigid panels perform mounted on a T5 roof come winter—you're dealing with potential shading...

The reality is that winter solar output in the UK is genuinely constrained by physics — you're looking at roughly 10-15% of summer generation depending on your latitude and panel orientation.

The real killer with budget controllers isn't always the initial failure—it's what happens during failure.

The payback framing misses the real question — what's your actual power budget? I've got a shepherds hut setup and ran the maths both ways.

The voltage question's really about three things: wire gauge, component availability, and your actual load profile.

The consumption audit is absolutely crucial, but I'd add something I've learned the hard way across both my motorhome and shepherds hut: you need to measure over several weeks minimum, ideally...