Solar Shading

Everything You Need to Know

By Adam Glick, Sr Consultant, NATiVE Solar

Solar PV (photovoltaic) panels create electricity from the mostly visible spectrum of solar radiation.

Here’s how it works in a nutshell:

Sunlight Hits the Panel: When sunlight strikes the surface of a solar PV (photovoltaic) panel, it excites the electrons in the semiconductor material (typically silicon) within the thousands of individual solar cells that comprise each solar panel.

Electron Movement Creates Energy: The excited electrons flow through the material semiconductor generating increasing electric current as it goes. This flow of electrons results in the generation of direct current (DC) electricity within the panel.

What Is Solar Panel Shading?
Solar shading is simply any shadow created by any physical obstruction which then falls onto one or more installed solar panels.

Common causes of shading include nearby trees, buildings and construction, debris like leaves or dirt, and of course weather-related factors (i.e. cloud cover)

Even small amounts of shading can significantly impact solar harvesting performance. (and not in a good way!) This is because the thousands of small, individual solar cells which make up a PV panel are typically electrically connected together in series to increase the output voltage. In a series circuit, the current passing through each cell must be the same or the power drops to the level of the lowest performing individual cell.

Any (individual or multiple) shaded cells in a single solar panel will limit the amount of electrical current (power!) for both that panel – and all other attached to the entire string of solar panels – this can significantly diminish the overall solar energy your system can harvest. Modern solar manufacturers are increasingly using clever design approaches to minimize the effects of solar shading – but all currently available solar panels are still susceptible.

Mitigating the Effects of Shading
Technological solutions: Microinverters (such as those made by Enphase) and power optimizers installed behind each solar panel can help by allowing non-shaded panels to continue to produce at top efficiency – even when one or more panels in a “string” are affected by shading. Although less common for residential solar installations, using bifacial solar panels and tracking systems can also help to alleviate potential shading issues.

Strategic design and installation techniques: As long-time solar practitioners, the NATiVE team uses complex site analysis tools to detect, assess and avoid high-shade areas when designing our preliminary recommendations. Of course, initial and/or ongoing tree trimming and vegetation management may also be important for our clients to consider and plan for – as is regular maintenance and cleaning to remove dirt and debris which may not have been fully removed by rain as designed.

How NATiVE Solar Helps You Optimize Solar Performance and Value
For 17 years, NATiVE has been here to help both our residential and commercial-scale clients navigate the potential intricacies and trade-offs related to solar and battery energy storage (BESS) design and system construction. Our highly-competent and well-trained staff utilizes only best-in-class tools and process/project management methodologies -along with careful, consultative requirement discovery engagement- to help ensure every NATiVE project exceeds our customers’ best expectations.

Get in touch with one of our expert solar consultants and let us provide you and your family with a complementary site survey (complete with solar shading analysis) and preliminary set of recommendations backed by nearly two decades in continuous operation under the same ownership.