Solar Gurus, please disect!

[SteamyTea]

47 minutes ago, SimonD said:

north face

So put up expensive panels that have lower efficiency, facing away from the sun for 9 months of the year. Just offer to pay a quid per kWh for your electricity.

There are much easier cash savings to be made.

[Nickfromwales]

9 hours ago, SteamyTea said:

So put up expensive panels that have lower efficiency, facing away from the sun for 9 months of the year. Just offer to pay a quid per kWh for your electricity.

There are much easier cash savings to be made.

North facing does come into play for some of our proposals, but only when economy of scale (and sufficient irradiance) justify it; mostly on very large or commercial projects but almost never sensible on domestic.

[SteamyTea]

1 hour ago, Nickfromwales said:

North facing does come into play for some of our proposals

Nearly half the yearly production though, so effectively doubling the installed price.

 

Left is South facing and right is North facing.

 

[SimonD]

15 minutes ago, SteamyTea said:

Nearly half the yearly production though, so effectively doubling the installed price.

Nowhere near doubling the install cost, partly because it's a self install. It takes me up an inverter size (just), but this is helpful if I can add more panels somewhere else in time. The marginal cost of this is less than £100 for the inverter up-size, plus about £500 in panels and the rails, a few hundred quid maybe. Using planned 510W panels, and only assuming a 30-35% generation ratio, I'd still get about £120-£250 generation gain per year - it's essentially a free way to widen the generation window during the summer due to gains morning and evening. Personally I think the numbers actually stack up as the TOU tariff we're on is 30p peak/kWh

A few years ago someone in the solar industry talked me out of accepting a load of panels removed from a commercial installation where they were going through a standard 10 year swap out. I always regret that decision. If I have the opportunity now to build in long-term almost free value, I'm going to take it.

 

[SimonD]

1 hour ago, Nickfromwales said:

but almost never sensible on domestic.

This is a timely reminder to always run the numbers!

[Bancroft]

On 16/06/2026 at 17:28, saveasteading said:

There should be clamps designed for every standing seam product, allowing you to use standard solar panels.

Do you mean like this?

 

Looks like they grip on the vertical seam section and then provide a mounting point for the solar panel, though not sure how you size roof seam width to solar panel width without ending up with a Meccano set's worth of scaffolding.

 

Has anyone got any experience of using these?

 

 

[saveasteading]

4 minutes ago, Bancroft said:

Has anyone got any experience of using these?

That is what I meant, but they may have to differ in geometry, and perhaps have added bearers/infill pads, to suit each particular panel.

I really meant that the panel suppliers should be more engaged in advising on the subject.

 

The clamps shown will grip very tight to whatever is between the jaws but might  damage it.

Plus will they rip a lightweight material (aluminum)?

It would be easy for the panel manufacturers to design or recommend an appropriate clip. I feel they are deliberately avoiding the issue.

 

Then there is the issue of how the panels themselves are fixed. It is usually a clip-on to an upstand cleat. 

How are they fixed down and can they withstand uplift?

Were the designers advised to allow for solar panels? Or did they ask?

 

My other issue is why one would pay  a large premium for standing seam, then cover it.

 

My experience of this is second hand. Having built a multitude of metal roofs, none had standing seam because I advised clients of the pros and cons.

But our supplier, who had many options including SS,  was very nervous about the number of buildings throughout Europe, Standing seam especially but also profiled,  that were being solar panelled without consultation on dead weight or uplift.

 

 

 

 

 

[torre]

I'd have thought there's a structural adhesive that could cope with bonding brackets, rails to fix the panels to.

 

8 minutes ago, saveasteading said:

why one would pay  a large premium for standing seam, then cover it

+1, especially if you're looking at flexible panels for a curved roof?