Hello,

I'm looking to build a 'green' home in the Twin Cities area and have been investigating PV options.   I've read that in general it's best to orient fixed PV collectors at the same angle as the locations latitude - 45 degrees, then, where I am.   I know that some sort of solar-tracker system would increase output but those sound pretty complicated.  I'm wondering if anyone has any ideas, experience, links, etc. that would show in general how much production would increase if just the angle of the collectors was changed with the changing seasons, i.e. higher angles in the winter and lower in the summer.    Thanks.

Hi, in summer your want your latitude and in winter you want your latitude +15. I am over in Green Bay, also at 45*. I have mine about 55* and just leave them there. It helps with the snow in winter and in summer you have so much more sun tipping them that 10* back down doesn't matter much, but in the dead of winter you want as much as you can get. Some people will mount they panels so they can manually tilt them up and down the 15* and change them twice a year, I used to do that ;)

With our weather conditions I would think any tracking system is asking for trouble. I have heard to just use what you would spend on a tracking system and by additional panels and you will get the same power you would with tracking and have nothing to break or mess with.

If you have limited space it might be something to look in to.

I attended a local solar design for Alaska class last week and it was the opinon of the Professor from the UofA that in our climate 90 degrees orientation works best because of two reasons. 1 Snow and rime ice will not stick to the collectors. 2. The reflection of the sun off the snow is not incindental, there is some gain to be had.
Now the cavaet is if you mount the PV's where they are easy to clean and tilt then I would go for the degree tilt to maxmize the gain for your location. Most people usually find that a pita fairly quickly and also mount them fairly high as to make it somewhat dangerous to climb up and readjust.
Jim