Archive for the ‘Renewable Energy’ Category

Switching the brain channel for solar.   Leave a comment

I’ve been doing a lot of thinking about making my house solar powered.  I see two problems with it, but neither are really technological problems.  They are mental problems on the part of the end user.

This the Cansolair 240.  It has a heat output approximately equivalent to a 1200 to 2400W electric heating element, or 10,000 BTUs.  It’s actually a pretty good thermal solar panel, one of the best.  The first mental problem you have to get over is the ratio of size to energy output.  My toaster and the 240 both produce about 1200W of heat.  The panel is nearly 4 feet wide and 8 feet long.  It has volume of about 15 cubic feet.  The toaster can be held in one hand and has a volume of less than a 1/6 a cubic foot.  I don’t feel like running the numbers, but I suspect, all things considered, that the panel actually takes up less space if you tally everything.  The panel is an energy producer.  For a fair comparison the toaster needs to have added it’s individual share of the the hundreds of miles of power line, the tens of thousands of cubic feet of coal mine, transportation system, and power plant.  (If I was feeling up to it, I could average those things out and get a number, but meh.)  The point is here, you are not used to seeing your share of the entire power production and consumption apparatus  combined and attached to your wall or roof, so it seems disproportionately large.

The other issue is winter heat.  A problem with heating a house with solar energy is that when you need the most (winter) you have the least available and when you need the least (summer) you have the most available.  Winter in the midwest sometimes passes days without sun, and if you are going to go 100% solar, you need a huge thermal mass, and correspondingly huge collection area to make up for it.  The house, in essence, becomes an inhabited box behind the solar thermal collector, which in turn dictates virtually every aspect of the house’s shape and size.  This is particularly a problem if you are being environmentally responsible and rehabilitating an old house instead of building a new one.  The technological solution to this is to separate the house from the collector, and make the collector a fence like object in the backyard.  However, there is a simpler mental solution: drop the requirement for 100%.  The law of diminishing returns kicks in at different points in different locations.  Accept 100% when the sun shines, 0% when it doesn’t, and cover the gap with the responsible use of the lowest foot print technology you can.

100% renewable is almost a religious fanaticism. People use huge amounts of non renable resources to get that last 15% or so. Just slow down, relax, and be content with very good instead of best.