As we all know, south facing produces the most. East and west produces the longest. What about combining the two into one ? Take 2 rows of panels, sitting side by side on a south roof. Like 2 playing cards sitting side by side and touching. Now take the cards where their touching and raise them to form them into a inverted v /. Now take several sets of rows and do the same thing. /\/\/\ Calculate the angles to be 15 degrees. Take 2 68" panels sitting end to end, left panel, left side on the roof, right side 17.6" high. second panel, left side 17.6" high, right side on the roof. Both 17.6" connected together to form center. 0 / 17.6 \ 0 Two right triangles back to back.