The following are examples of various types of mounting approaches we've used for solar photovoltaic panels.

Ground Mount - More expensive than roof mount but less than pole mounts, they are the easiest to clean on a regular basis.

Pole Mount - More expensive than roof or ground mounts, they are almost as easy to clean as ground mount panels but don't take up as much ground area. They allow for planting a garden or flower bed under the array and can get the panels up and off the ground if there is ground level shading from low-growing bushes to the south.

Roof Mount - Roof mounted modules are the least expensive to install but are difficult to clean on a regular basis. Note the vertical spaces between rows - these spaces keep the array cooler (and therefore more efficient) and provide access for cleaning leaves out from under the modules.