I’m astonished to look back at old posts and find that it is seven years since we fitted our solar panel on Herbie. Perhaps that roof corrosion cause by the magnetic panel frame feet is a bit more forgiveable after all. Anyhow it looks like I’ll complete the roof repair and repaint before too long so it’s time to think about what comes next. More solar, that’s what. I can’t remember what I paid for our existing solar panel but I’m sure that prices have dropped by something like half since then. So we’ll be getting a second panel soon.
My ingenious two way tilting panel frame has done pretty good service.
It does what it says on the tin (sorry, aluminium), but it’s a bit less sturdy than I would like, and it can get it’s knickers (or knees at any rate) in a twist during the folding and unfolding, so I’m thinking of a stouter and simpler design. Hunting round the web I found some that work like this.
Basically three bits of aluminium angle at each end of the solar panel. The prop piece can be placed where you like using the holes and screws attached to plastic knobs, and when you lay the panel flat, the screws secure the panel flat using the end holes. As you can see, you can tilt the panel either way to face the sun. (Our own measures show that titling the panel makes quite a difference in the amps generated a lot of the time. You can buy frames like this for £50 a pair (for one panel) plus carriage. It might seem dear, but if you cost up all the bits and pieces and include their labour and profit, it’s not unreasonable.
It’s a simple principle but I plan to make something a bit different in that in the ones I have seen the top piece is a length of angle that sits under the solar panel, whereas I plan to rivet a flat bar to the side of the panel frame, but deeper so as to make room for drilling the holes. Making my own reduces the cost considerably of course, and it’ll be more bespoke to my solar panel sizes and be a bit of fun to make. Making two pairs, one for the old panel and one for the new makes economic sense as postage for the aluminium costs no more for two lots, saving £15. The best price for the aluminium, in case anyone wants to get some, seems to be at aluminiumwarehouse.co.uk where they will also cut pieces to your required length for a small charge. Not a bad idea as the full lengths of stock angle are and unweildy 2.5 metres.
My idea is to have the bottom rail and the upright in 50x25mm angle for rigidity and as I said the top piece as a flat bar rivetted to the side of panel frame, but much deeper to allow for drilling the adjustment holes. All 3mm thick, which should be plenty strong enough.
This time I won’t be using magnetic feet, which as we now know are prone to rust unless you buy prohibitively expensive ones. I’ve been looking at adjustable furniture feet, the sort you find on steel desk legs, which I think I will glue to the roof. People seem to recommend the adhesive/sealant Sikaflex for this sort of job, so I’ll give that a go. Various screwed knobs can be found on ebay. You have to shop around for this stuff if you don’t want the costs to run away. The building ought to be easy, mainly a matter of drilling holes, which in aluminium is simple.
So that’s the plan for the frames. There is still time for someone to point out any flaws before I order the stuff. Next post I’ll tell you my thinking on the solar electrics.