Let's Solarize Our Future

Site assesement

With PV modules, energy production is golden—as long as sunshine is hitting them. But shade (and even partial shade) can make your modules as useful as garden gnomes.

A PV module’s output is directly proportional to the amount of sunlight hitting it. Modules produce electricity when photons—little packets of energy contained in sunlight—hit the cells and knock available electrons loose and into motion. When fewer photons hit the PV cell, for example due to haze or poor orientation, fewer electrons are put into motion, and less electricity is produced. But shade—even a small amount—can in some cases shut down production completely.

Solar Site Analysis Tools

Predicting shading throughout the year from various obstructions—such as tall trees, nearby buildings, roof dormers, and even chimneys—can be challenging if done by sight alone, requiring many observations over the course of the year. But several tools, including the Solar Pathfinder, the Acme Solar Site Evaluation Tool, and the SunEye, can help you quickly assess shading on your site throughout the year—with one site visit. Although these tools differ in technique and price, all will get the job done. All require that they be used at a proposed array location to evaluate it.