5 ms·

Around here (Boston) roofs tend to have a lot of obstructions: dormers, skylights, chimneys, vent pipes. They're also typically very steep (1:1) so North-facing

by jefftk 8y ago

Around here (Boston) roofs tend to have a lot of obstructions: dormers, skylights, chimneys, vent pipes. They're also typically very steep (1:1) so North-facing isn't an option. Then you lose some space due to shading from trees and other houses. When we got solar there was only room for panels covering 1/4 of our electricity usage.

Retric 8y ago
That’s an extreme situation as Boston is rather far to the north and has poor weather for solar. Covering a skylight with solar is a net energy win, as would taking down the tree(s). Trees are also going to block the front of your building even more than the southern facing roof. Getting shade from other buildings on your roof is also unusual for 2 story buildings.
- gumby 8y ago
  Not sure I would call Boston especially north as it is south of, say, Nice.
  - Retric 8y ago
    It’s 42.3601° N closer Toronto at 43.6532° N than New York City at 40.7128° N. By comparison Miami is 25.7617° N and still above the Tropic of Cancer 23°26ʹ which is the furthest north you can get where the sun is ever directly overhead. PS: Europe is kind of deceptive as the equator is so far down below the bulk of Africa. But so many maps stop at the top of Africa it’s easy to think of it as some sort of mid point. Further, due to weather patterns it’s warmer than you would expect.
    - goodcanadian 8y ago
      It’s 42.3601° N closer Toronto at 43.6532° N than New York City at 40.7128° N. It's relative, I suppose. From a Canadian point of view, Toronto is just about as far south as you can get.
      - gumby 8y ago
        What about Turks and Caicos :-) (Couldn’t understand why you guys weren’t enthusiastic for their offer)
- Johnny555 8y ago
  Covering a skylight with solar is a net energy win Just filling the skylight hole with insulation may be a net energy win but most people don't have the skylight to save on energy bills.
- jefftk 8y ago
  > Covering a skylight with solar is a net energy win, as would taking down the tree(s). Solar isn't the only thing people are optimizing for -- skylights and trees are pleasant. The trees also aren't on our property, and even if you removed all the parts over our property our east-facing roof area would still be completely shaded. > Trees are also going to block the front of your building even more than the southern facing roof. It depends on the situation. Our roof is East-West with a big Gable dormer halfway along the West side. The East side is fully shaded by a tree, as is the back of the West side, but the front of the West side and the South facing side of the dormer get good sun (and now have solar). Our house faces the street, and there aren't trees in front of our house, so front-facing solar would work well if that was a thing people did. > Getting shade from other buildings on your roof is also unusual for 2 story buildings. I agree it's unusual in general, but houses here are close enough together that some roof shading is the most common situation.
curtis 8y ago
There are clearly plenty of places where it wouldn't make sense. On the other hand, I can easily imagine that there are a million houses in the Great Plains and desert west where trees aren't a big problem.

by jefftk 8y ago

Retric 8y ago

That’s an extreme situation as Boston is rather far to the north and has poor weather for solar. Covering a skylight with solar is a net energy win, as would taking down the tree(s). Trees are also going to block the front of your building even more than the southern facing roof. Getting shade from other buildings on your roof is also unusual for 2 story buildings.

gumby 8y ago
Not sure I would call Boston especially north as it is south of, say, Nice.
- Retric 8y ago
  It’s 42.3601° N closer Toronto at 43.6532° N than New York City at 40.7128° N. By comparison Miami is 25.7617° N and still above the Tropic of Cancer 23°26ʹ which is the furthest north you can get where the sun is ever directly overhead. PS: Europe is kind of deceptive as the equator is so far down below the bulk of Africa. But so many maps stop at the top of Africa it’s easy to think of it as some sort of mid point. Further, due to weather patterns it’s warmer than you would expect.
  - goodcanadian 8y ago
    It’s 42.3601° N closer Toronto at 43.6532° N than New York City at 40.7128° N. It's relative, I suppose. From a Canadian point of view, Toronto is just about as far south as you can get.
    - gumby 8y ago
      What about Turks and Caicos :-) (Couldn’t understand why you guys weren’t enthusiastic for their offer)
Johnny555 8y ago
Covering a skylight with solar is a net energy win Just filling the skylight hole with insulation may be a net energy win but most people don't have the skylight to save on energy bills.
jefftk 8y ago
> Covering a skylight with solar is a net energy win, as would taking down the tree(s). Solar isn't the only thing people are optimizing for -- skylights and trees are pleasant. The trees also aren't on our property, and even if you removed all the parts over our property our east-facing roof area would still be completely shaded. > Trees are also going to block the front of your building even more than the southern facing roof. It depends on the situation. Our roof is East-West with a big Gable dormer halfway along the West side. The East side is fully shaded by a tree, as is the back of the West side, but the front of the West side and the South facing side of the dormer get good sun (and now have solar). Our house faces the street, and there aren't trees in front of our house, so front-facing solar would work well if that was a thing people did. > Getting shade from other buildings on your roof is also unusual for 2 story buildings. I agree it's unusual in general, but houses here are close enough together that some roof shading is the most common situation.

curtis 8y ago

There are clearly plenty of places where it wouldn't make sense. On the other hand, I can easily imagine that there are a million houses in the Great Plains and desert west where trees aren't a big problem.