How much does orientation of PV solar cells affect their efficiency?
Gary in Prescott Valley

Gary, even north facing solar cells catches a decent amount of solar.  And putting panels on east or west roof pitches is a pretty good option.  To make up for the lower efficiency, you just add a couple more panels.  Housing and the environment connect 100% of maximum annual collection with a South face, 94% at a Southeast face, 77% at an East face, 54% at a Northeast face and 42% at a North face.  Installation of tracking devices to follow the sun is probably not worth the extra money.  You might possibly be gaining about 2% gain at best.