Going Solar on a Budget: A Case Study

“The idea of going solar always appealed – I think it appeals to the vast majority of people. I mean you’d have to be mad not to want some free energy, now wouldn’t you? But the problem for most of us mere mortals with mortgages to meet, bills to pay and kids to bring up is that doing it just seems so expensive.”

Well, that’s the case in a nutshell from Geoff Walsh – but he’s not the sort of man to give up on a good idea too easily, which is why he decided to go solar on a shoestring.

Getting Started – By Accident

“It’s funny really,” Geoff explains, “because it all started from my youngster’s recycling project – sort of going green by being green, if you see what I mean.”

Peter, Geoff’s son, had started collecting aluminium cans over the summer holiday. The family live in a small seaside town which sees more than its share of holiday makers and day trippers during the summer and even today with plenty of local recycling facilities, there’s never a shortage of discarded cans and other rubbish.

“A couple of years back, Peter just decided to start collecting them; to be honest I think he was bored – most of his friends were away and he was at a bit of a loose end. I said he could store them round behind the garage – but I never expected what happened next.”

Peter had been putting his cans into black plastic sacks, ready to take down to the local recycling centre and when Geoff went to load them up he was instantly struck by how hot they were.

“They were scalding! That part of the garden faces south and this was mid-August and a good summer. Well, it set me thinking – there had to be a way I could make use of all that energy.”

Effective Solar Collector

It became obvious to Geoff that he had accidentally stumbled on a rather effective, budget solar collector and he set about researching what he could do with it, using the Internet and his local library.

“I found that most of the DIY designs for solar collectors that are readily available online were for solar water heating, but I wasn’t at all sure how I could convert old drinks cans into something I’d be happy to strap onto my roof – much less that the council planners would approve of! But it got me thinking.”

Having decided that the conventional plumbing route was out, Geoff started looking at things from a different standpoint and it dawned on him that while heating water might be a problem, he had a ready-made source of hot air. As he says, “that really was the turning point.”

Building the DIY Solar Panel

The design Geoff came up with is as simple as it’s effective. At its heart are columns of aluminium cans, each with a hole drilled in its base and painted matt black, glued together with heat resistant sealant and mounted in a wooden frame made from recycled pallet wood. With a pane of glass added to the front and a length of sink waste pipe attached to the top, Geoff’s solar panel is a substantial piece of equipment – but does it work?

“I’d been wanting to find a way of warming my shed for ages, but I didn’t want to have to put a heater in there – it would take up too much room.” (Most of Geoff’s shed is hidden behind some tall trees, so only a small part of it gets the same benefit of the sun that the rest of the plot enjoys). “I placed my panel on the sunny side of the shed, fitted the pipe into a hole I’d bored in the wall and then kept my fingers crossed.”

How it Works

The idea behind Geoff’s panel is wonderfully straightforward; as the air inside each black-painted can warms up, it rises, drawing cooler air from the can below it in the column. Air from the ones at the top flows out of the pipe and into the shed, while a vent at the bottom of the panel allows cool air to enter from the garden.

“So far, it’s been a great success and the biggest difference has been during the spring and autumn, when it used to be quite unpleasant to be working in the shed; now there’s still enough heat in the sun to make it surprisingly warm in there. Mind you, in the summer, if I forget to close the intake hole, it gets so hot I have to open the door and all the windows!”

The Solar Budget

The cost of this system has been incredibly low, with a pot of matt black paint being the largest single expense. Add to that a few tubes of sealant, a small amount of kitchen pipe and a piece of glass and Geoff reckons that he built the whole thing for under £25 – and he’s already begun thinking about how he can use the same idea elsewhere around the home.

One thing’s for sure, as an example of how to go solar without breaking the bank, it’s hard to beat.