View Single Post
Old 08-31-16, 10:31 AM   #5
Supreme EcoRenovator
AC_Hacker's Avatar
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,002
Thanks: 303
Thanked 712 Times in 532 Posts

Originally Posted by SDMCF View Post
...I have 100 evacuated tubes and for three months at the end of the year, when there is typically heavy cloud cover here, they produce basically nothing. I don't know what the cloud cover is like in Seattle but don't count on a solar contribution year-round...
Good advice. I have noticed here in Portland, OR, which has very similar weather pattern as Seattle, that even in overcast flat panels can hit 80F in winter over cast. 80F is not a lot, but it is a contribution to water preheat. I must add, that while I did see a panel deliver 80F, I did not have any information about the rate of energy falling on the panel.

The panels will be big producers all during the summer, gradually less during the shoulder seasons.

If storage is possible that would definitely be a winning strategy. If you can get your GSHP holes drilled, dumping your summer heat into the ground would be a real winner. The problems I foresee with that is water flow through your loop field would wash away your heat.

You could dedicate 2 or 3 panels to heating DHW for the house through the summer, and use the DHW heating method of choice for the non-sun months. Likewise, you could dedicate the other 2 or 3 for DHW in your shop.

Some kind of control will be called for, because there are many intermittently sunny days even during the winter. Shoulder seasons, even more intermittent.


I'm not an HVAC technician. In fact, I'm barely even a hacker...
AC_Hacker is offline   Reply With Quote
The Following User Says Thank You to AC_Hacker For This Useful Post:
Geo NR Gee (08-31-16)