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.
Solar panels south facing wall.
Therefore directions like southwest or southeast are fine.
Here are simulations for roof at 30 degrees facing south and mounted vertically on wall facing south.
4258 kwhrs yr on the roof and 3167 kwhrs yr on the wall.
This is less expensive and also gives easy access to the panels if you need to clean them brush off snow or do any other maintenance.
Also there will be more risk of shade on the wall.
Wall mounted vertical panels are still an energy generating option for solar installers.
Well when it comes to solar panels west is second best.
Wall mounted solar arrays produce less but work in a pinch.
Go west young one.
Updated may 18 2020.
Solar panels should face south for any home in america to obtain maximum power generation.
But what if you don t have a suitable south facing roof.
However solar panels can be orientated on any roof that faces south of either east or west.
In the northern hemisphere the sun crosses the sky a little to the south which means putting solar panels on a south facing roof is the best way for homeowners to capture the most solar energy.
Installers have adapted pre existing mounting and racking technology or developed their own to install solar panels on the south facing walls of buildings.
If you have space in your yard the panels can also be mounted on the ground.