in flat country with no trees and other houses around yes. all it takes is a shadow and you might get more power in the afternoon from the white wall of a house across the street.
I just checked - the panel on my toy system faces directly east but only gets about 2ish hours of non-optimal light a day (between 10ish and 12ish - after that there are chimney shadows) due to houses being in the way. This is peak in summer - for the rest of the year i get less because the sun is lower longer.