Friday lunch recap 10/4/12: Solar thermal panel seasonal prep

The subject of Friday, 10/4’s lunchtime presentation was solar panels. More specifically, the Green Garage’s solar thermal panels, which we’ve recently turned on in preparation for the coming cool weather.


Joe Gallagher, who did construction design and management for the Green Garage (and is currently doing the same work for our residential project, the El Moore), ┬áis responsible for keeping an eye on the GG’s panels. He gave us a quick introduction to the GG’s solar thermal heating system, which includes an array of ten panels on the roof that heat 5,000 gallons’ worth of water. When the temperature drops and the building starts requiring heat, the water is pumped through tubes in our floor, providing radiant heating.


Joe walked us through the process by which the tanks start heating the water, which started on September 2nd. By September 3rd, we saw an increase in the water temperature in the tanks of 20.8 degrees.

Joe’s goal around this time of year for the past couple years has been to get the water in the tanks to a temperature of 160 degrees. Are we there yet this year? Joe thinks so (an external sensor suggests the temperature recently hit 155, and since it’s just outside the tank, he thinks the water is in fact hotter), but our sustainability labs are going to get a firmer answer today, actually, with the use of a very long thermometer.

Whether we get to 160 or not, though, we’re optimistic that we’ll be able to comfortably heat our historic, 12,500 square foot building all winter with free energy we’re harnessing from the sun. (But we’ll get to 160.)

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