In general solar panels that are oriented directly east or directly west will produce about 20 percent less electricity than if they were facing south.
Why south facing roof get more sun.
However the economics of installing solar panels on a roof that does not face the south still usually stack up for the homeowner.
Because the sun rises in the east and sets in the west the side of the building that is utilized for solar gain needs to be facing the south to take maximum advantage of the sun s potential energy.
Why orientation matters with rooftop solar.
At the poles north and south slopes tend to be either shrouded in darkness all winter long or bathed in sunlight all summer long with only slight variation between the slopes in spring and fall.
Try both summer and winter orientations for the axis.
Panels mounted on a standard pitch roof facing east or west will produce approximately 15 less output than panels mounted on a south facing roof of a standard pitch.
A good way to visualize this is to get a globe and tape a monopoly house or sugar cube to it to represent your house.
This change in the sun s apparent angle between summer and winter is why that works.
Near the equator north and south facing slopes receive roughly the same amount of sunlight because the sun is almost directly overhead.
Then use a flashlight to represent the sun and rotate the globe.
I live in a north facing home and i love the sun i get in my bedroom.