Rooftop Solar LayoutEnter the roof, parapet and stair room. It lays out every panel row with shade-free gaps for the winter sun, and gives the kWp, panel count and yearly units that really fit.

Rows face the equator. The gap behind each row keeps the next row out of shade for the hours you pick on the shortest day, so it is shade-free all year. Parapet and stair-room shadows at those hours are kept clear too.