A SOLAR TOURIST SEES HER FIRST EVACUATED TUBES

Last Saturday was a day I wait for all year long –

The American Solar Energy Society (ASES) National Solar Tour .

...This evacuated tube system is beyond gorgeous!

This  great event happens every October, so put the first Saturday of October on your calendar for next year if you want to know more about what solar living actually looks like.

More than 5,500 buildings using solar energy in 3,200 communities across the U.S. threw open their doors for the day to share what they are doing with anybody who wants to take a peek.

Now in its 15th year, the number of peekers has grown to 160,000.  Doug and I have been solar tourists for four years now.   At first we would try to see as many places as possible, but it is too good to rush. This year we made  our way to three sites winding along country roads through the beginnings of fall color under a sky of flying clouds.  What a win-win day!

The Wisconsin Solar Tour is organized by the Midwest Renewable Energy Association (MREA).  Check out their cool solar tour site here .    They divide the state into 5 regions.  Click on your region and see a list of all the sites on the tour with detailed descriptions of what each site features and directions to find it.

This year, our focus was passive solar and solar hot water.  We particularly wanted to see the new evacuated tube solar collectors in action, and we found them outside Dane.

Evacuated tubes have been used for years in Germany, Canada, China and the UK, but I just heard of them this year at the MREA energy fair.  Each evacuated tube is actually two tubes.  The outer tube is transparent.  The inner tube is coated with a coating that absorbs solar radiation well.  The space between the tubes has the air pumped out.

It works like a glass-lined thermos because a vacuum is a good insulator.  This means that the inside of the tube can be heating up to 300 degrees F, but the outside is still cool to the touch.  This allows evacuated tubes to hold their heat in cold weather much better than flat collectors.

I haven’t priced them yet, but I understand they are more expensive.  I’m hoping the cost will come down quickly because I also think they are really beautiful objects.

I have come a long way in my aesthetic appreciation of solar collectors.  I used to think they were butt-ugly and spent a lot of time thinking about where they could be put that would both collect maximum solar energy and be out of sight.

...These solar collectors double as a shade screen for the chicken run.

These days I see solar collectors as a kind of badge of honor and a form of ornament.  Wherever I see them, I smile, and I don’t object to putting them front and center in our building site.  Doug is planning to attach some directly to our south facing wall.  (I’m sure he will post about this soon.)  Then they can produce reasonable heat in the winter and be pretty non-functional in the summer.  That would solve some of the excess summer heat issues that often accompany solar hot water systems.

Aside from all the technical details that we learn first hand on the solar tour, there is another powerful benefit of this glorious national solar exploration.

...With solar electric, solar hot water and a wind generator, this home owner is off the grid.

Everyone – without exception – whom we have met on these tours is a genuinely friendly  person — a personI am glad I met.

We drove home Saturday night feeling like there is a growing tribe of solar pioneers out there , quietly changing the way things work.

What do you know about evacuated solar tubes? I’d love to hear from anyone who has experience with them.

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