Concept

There are two angles of orientation to be considered: angle off solar south (azimuth is the angle off north, but the same concepts apply) and angle tilted from the horizon (altitude).

Azimuth: For the best solar opportunity, homes should typically be oriented with their long side, with the majority of windows, toward solar south (about 14 Degrees E of magnetic south in our area).

One of the things I find most unsettling is that the vast majority of homes built today do not take the sun into consideration. You drive through the countryside, where large amounts of good farm land is being converted into residential property, locations where the builder does have a choice, and you see houses slavishly oriented toward the street. What a pity, what a waste!

Altitude: Recommendations for tilt are a little more varied, that is it depends… It depends on what you are trying to maximize and when. For example, are you trying to maximize annual energy or winter energy?

Application

Azimuth: Our house is pointing (south windows facing) toward true solar south, not toward the road, but also, thankfully, not towards my neighbor’s back windows…

There is a lot written about “adjusting” the orientation to accommodate local micro climates (clouds burning off in the morning, for example), or shading (neighbor’s trees or buildings or a nearby hill), or spectacular views, or heaven forbid “the street.” In my case, I had none of these issues. But if you do, take solace in the fact that you will get over 97% of the sun’s energy if you are within 10% of true south. Even if you need to be off south by as much as 22 degrees, you will still get over 92%. If your goal is winter heating, be wary of adjusting any further; 100% Solar is a difficult challenge and there is no sense in tying one arm behind your back.

Altitude: As I said, tilt depends. For PV, grid connected (mammoth battery), I want to maximize my annual power generation. For this a tilt angle of about your latitude (about 43 degrees here in the Capital District) is a good rule of thumb. My garage will have a 9/12 pitched roof, which is about 37 degrees. This is close enough for my purposes. The main problem I will have is winter snow. For that reason, it would be better a bit steeper, and maybe it will be when I get to building the garage…

For heat, I want to maximize winter collection. The simple rule of thumb is latitude + 15 degrees (43+15 = 58 degrees); however, a bit more accurate is latitude * .9 + 29 degrees (43*.9+29 = 68 degrees). I will set my “year-round” collectors for domestic hot water at about 60 degrees and a set of winter collectors at about 80 degrees – no snow hanging around these babies…

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