Many people want to install solar panels but their roofs are very shaded. Is it worthwhile to install solar panels?
Clearly, solar panels produce more power when they are in direct sunlight, but they do generate some power when shaded. Here are the typical reasons for shady roof areas and how to place solar panels to take advantage of the light that is available.
Solar Orientation
For optimal power production, it’s best to install the solar panels on a south-facing roof.
If the panels point either west or east, they will not get as much direct sun during part of the day. If the panels face east, they will produce a lot of energy in the morning but very little in the late afternoon. The reverse is true if they face west. North-facing solar panels will receive almost no direct sunlight, so we don’t recommend you install them on the north side of your roof.
To determine the power generation loss due to orientation, use the PVWatts calculator tool and edit the azimuth field, which represents the angle at which your solar panels must be placed.
Trees
Although trees are wonderful for so many reasons, they are not necessarily compatible with solar panels unless they are planted on the north side of the home.
Trees on the south side can be most problematic because they can block midday sun, which is very important for overall power production. Trees can also prevent passive solar gains that can keep your heating energy use down in the winter.
There are a few things to keep in mind with trees. They could shade your solar panels more in the colder months when the sun is at a lower angle (especially if you live farther north). It is also important to consider the type of trees and how much they will grow.
Some smaller trees can be pruned to keep them small while some trees are just immense. Deciduous trees will shade your panels less in the winter months than conifers because they lose their leaves. However, even branch shade does have an impact on energy production.
Dormers, Gables, and Chimneys
These roof features are another culprit for solar electricity production. Aside from strategically placing solar panels where they aren’t shaded, there are few ways to get around these architectural obstacles.
An experienced solar installer will be able to place the panels where they receive the least amount of shading. Unfortunately, this might limit the size of the array.
Other Locations for Solar Panels
Keep in mind that you can install panels on a garage, as an awning, on a carport, or even on a trellis. This will probably increase the installation cost, especially if you need to purchase materials to reinforce the trellis or carport. Yet, these structures can be useful solar locations and provide other benefits.
Join a Community Solar Farm
Community solar gardens or farms are owned by a group of people or a company. They allow a group of households and businesses to use the renewable energy that off-site solar panels generate without installing the solar panels on their properties. Solar farms are ideal for renters, apartment dwellers, low-income households, and people with shaded roofs.
Some states have legislation in place making this arrangement more feasible and economical. Currently, Massachusetts, New York, Minnesota, and Colorado are the the top states for community solar farms. But 15 other states also have policies supporting community solar projects, and in several other states, utility providers and other groups are working to offer community solar. If you live in one of these states and have a shaded roof, joining a community solar farm might be a great option.