Is it necessary to have a south facing exposure to have a solar power system?

MEP Solar
2

yes it is

3

East/West works quite well. I installed 10 Mega watt east/west system in Germany in 2013 and you have a lot more watts per sq. ft with that system. So the loss in output at 6% can be offset with the increased watts in one acre of solar field.

4

It is not entirely necessary to have a south facing roof. A south facing roof is just the most beneficial for optimal production.