DIY Coke Can Solar Heating Panel

Upcycling is a way of life here, but that is only one reason I love our new Coke Can Solar Heating Panel. The best part is all that lovely heat in our old house. Before we installed the panel, we often saw winter temperatures warmer OUTSIDE than inside. Admittedly, the winters in Northland aren’t known for being punishing, but going outside to get warmer isn’t something I like to do.

Plus, Frugal Man calculates that using the system will cost us approximately $1.50 in electricity per year. No typo there. That is PER YEAR. You can see why I gaze upon our panel fondly.

The panel consists of Coke and beer cans, plywood and a sheet of polycarbonate. We used a whole sheet of plywood as a base, so it is HUGE 2.4m x 1.2m (7’11″ x 4′). Many people build similar heaters with old window panes, so don’t think they all have to be so massive. It’s just that we weren’t messing about when we built ours. We mean business!

How we built the solar heating panel

We started out with a whole heap of cans. Over 300 of them.

Some we collected on our own over the summer, but the vast majority were donated by friends or scrounged. Frugal Man cut out the bottoms of the cans with a drill press then I washed them. There were many slugs. And snails. And the house smelled like stale beer.

Next Frugal Man cut the tops of the cans to form baffles. I tried to do this, but the tin snips were too big for my hands and we couldn’t find a smaller version that I could use comfortably. He worked on baffling these over the course of several evenings whilst watching TV.

When he was done baffling the tops, he glued the cans together in sets of three. They were eventually glued together in columns of 16, but sets of three were much more manageable to have sitting around the living room.

Once the cans were glued in threes, he spray painted them a matte black all the way around. I thought he’d just paint the front where the sun would hit, but he’d read that you got improved performance with an all around spray. We used about seven cans of spray paint.

He installed the cans in columns in the plywood box he built that we’d painted with some dark brown fence paint we had lying around. We ended up with 17 rows of 16 can high columns for a total of 272 cans. The columns fit into holes he’d drilled in the plywood that connect the cans to the top and bottom manifolds.

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