Thursday, September 21, 2006

a parabolic workshop light

I had made up a number of four foot parabolic solar reflectors for prototyping the solar heater project.

By supporting a single four foot florescent tube at the focus of one of these reflectors, I made a very effective workshop light, shown here illuminating my garage workbench.

The same ribs are used as in the longer, eight foot reflectors but with shorter side rails.

I haven't done a scientific test against a two tube fixture without a reflector, but I'm very pleased with the even and bright lighting of the bench surface and delighted to be using half of the electricity of a two tube fixture which I might have otherwise used without the reflector.

Tuesday, September 19, 2006

the end of another season

It's the end of another wonderful summer here in southern Ontario. For the first time, we've managed to heat the pool without burning any propane. (The solar tracking parabolic heater is behind the fence in the picture, click to enlarge). In fact, last month the propane storage tank was removed since we were being charged rental by the propane supplier. I would have liked to have kept it here as another potential energency fuel source, but realistically have no use for it. Our propane pool heater sits idle and disconnected.

This is fine while the sun shines.

Unfortunately, the weather here has been overcast, cloudy, rainy and cool throughout the end of August and most of September.

The sun comes out only infrequently and it is seldom for long enough to even bother turning on the pump and the heater tracking. Most of the time, the weather forecast has looked like this:

So the idea of a solar heater as a "season extender" depends on the weather (and your location).

Without sun, the pool tends to follow the ambient temperature and it is now cool enough that no-one wants to swim in it anymore. It really is time to start thinking about putting it away for the winter.

I consider that the project is a success and that our home made solar parabolic heater contributes meaningfully to pool heat and helps in a small way to prevent some global warming. However if we lived in a sunnier climate, the results would be even more meaningful.

For much of July, the pool temperature was in the 82-85 degree range hitting a peak of about 86 in the middle of July. For next year, I plan to contue the building effort to fill the frame with collectors. I currently have six operating. The existing frame will hold 12 reflectors. This will double the potential heat output.

I am working on the plans. Progress has been slower than I had hoped because it has been a busy summer with other work.

Thanks for your interest.