Definitely, it's a good idea for now. However, one thing that scares me is "product lifetime of over 20 years". That isn't very long. Will people be able to renew their systems when the time comes? The manufacture and transportation of solar water heating system systems must be somewhat dependent on oil(?)

Margaret, you asked "one thing that scares me is "product lifetime of over 20 years". That isn't very long. Will people be able to renew their systems when the time comes?"

That's a tricky one for me to answer, not because I can't, but because I don't want my answer to sound like advertising for a service my company provides. I'll give it a try.The reason for the 20 year lifespan estimate is because the equipment sits on your roof, exposed to the elements, which is rough enough in Canada. Heck, most roofing materials don't last that long! Point in fact, I removed a system from a roof in Ottawa South last summer for that exact reason: the panels had outlasted the roofing shingles underneath them! And these systems have only been commercially available in their current state for about thirty years, say, the late seventies, early eighties. So saying 20 years is a safe estimate. Remember, sad as it is, companies give warranties as long as they expect everything to be ok, not when they think things will fail!That said, and this is where it gets dangerously close to advertising, my company regularly fixes up systems that have been on roofs since Trudeau was Prime Minister. They're not complicated technology, and most of the parts are simple plumbing and glass, something that will be always be available. However, there are some systems that use exotic means, vacuum tubes, curved mirrors, that will be very dependant on the longevity of the individual manufacturer for future replacements. So if that is of major concern to you, yes, stick to the "classic" systems!

"The manufacture and transportation of solar water heating system systems must be somewhat dependent on oil(?)"

I'd say VERY dependant. But name five things in your home that aren't. Every time I do that, it scares me, and I live in an off-grid LOG home ;-).But since the solar water heating systems reduce your future dependancy on either the utility grid or fossil fuel fired conventional hot water heater, I'd say it's a gain.

Hope that helped!

DJ

WRT Margaret's concern on the lifetime of flat plate and evacuated tube solar systems, outside of major breakdowns or damage, it should be possible to build, repair and/or overall these systems locally. The infrastructure may not be in place to carry this out at the moment, but that would change if the need arises. ( I currently make my own flat plate collectors and will have a homemade evacuated-tube system working by the end of this year).

After upgrading insulation and windows, installing solar DHW is the most important practical step for most people wanting to mitigate the impact of peak oil and natural gas -- not just in the category of residential energy, but across the board.

And again... Just this afternoon, doing a service call on a SDHW system that was installed on a roof down on Fallowfield when *I* was still in ELEMENTARY SCHOOL!

And the only thing wrong with it was some failed electronics, which took less than an hour to change out and it was back to pumping heat into the hot water heater, and slowing down the electric meter.

If only they built cars like that ;-).

DJ

BillC: Would you consider at some point posting instructions on how you made these on instructables.com (and then putting a link to them here)? Instructions on how to make homemade collectors of various kinds would be a very useful thing to have widely available through the internet.

You can find a number of solar thermal projects at instructables.com by searching for "solar thermal".