When thinking about installing solar panels, one of the most important things to consider is roof shading.
Shading can have a huge impact on the energy production of your solar panels. That’s why it’s so important to know how much your roof is shaded and how it will impact your solar production.
Plus, it’s also important to know how you can overcome the problems of shading and maximize the output of your solar panels.
CAUSES OF SHADE ON YOUR ROOF
The causes of roof shading come in several shapes and forms. These can be natural shading from trees and shrubs, or manmade shading from buildings and structures on the roof.
The most obvious and most common source of shading is trees. While trees are nice to have around your home, they can cause issues when it comes to solar panels. The shade these trees produce can block the sunlight falling on your solar panels and greatly reduce their energy output. Sometimes this shade is minimal, just a branch or two. Other times, it can be the entire tree shading the entire roof.
As we will address later, resolving the issue of tree shading on your solar panels can be a simple and easy fix.
Another source of shading on solar panels is other buildings. These can be buildings on your property, such as a barn or shed, or buildings on other people’s property, such as homes or commercial buildings.
The issue of shading from other buildings can be a bit more difficult to address, as we will discuss later. This includes legal routes to resolve the issue.
The final type of shading can come from obstructions on the roof, such as chimneys, skylights, vents, and even other solar panels. Shading from these obstructions is normally very minimal and can be addressed fairly easily. We will discuss solutions to this shading later in the article.
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HOW MUCH DOES SHADE REDUCE SOLAR OUTPUT?
Because solar panels create energy from sunlight, shading can create a big problem by blocking this source of energy. However, the resulting decrease in solar energy can vary quite a bit.
In general, the less shade there is the less of an impact there will be on solar energy production. If only a small branch or a thin vent pipe are shading a solar panel or two, solar energy production will barely be affected.
However, if an entire tree or building is blocking a whole row of solar panels, solar energy production will likely be greatly reduced or entirely shut down.
Thankfully, there are solutions to solar panel shading problems. Let’s explore those solutions and see if they could resolve your shading issues.
SOLAR PANEL SHADING SOLUTIONS
When it comes to resolving the issue of solar panel shading, there are several potential solutions. Each solution will depend on the individual circumstances of each household or business.
While trees are one of the most common sources of solar panel shading, they are also one of the easiest to address. Many times, trees can be trimmed or cut down to clear the way for sunshine.
But, does cutting down a tree to install solar panels make environmental sense?
In fact, A 25-year solar installation can offset more CO2 than the average tree can consume in the same period. In other words, your carbon footprint shrinks more if you remove trees to make room for a solar installation.
But what if the tree is on your neighbor’s property? Unfortunately, the only way that you could resolve this problem is by convincing your neighbor to trim or cut down their tree, or by having them agree to a solar easement.
A solar easement is a legal agreement between two parties that says one or both parties shall have access to the sun on their property. For instance, the agreement could stipulate that the neighbor without solar can grow trees up to a certain height, at which time they must be trimmed or cut to prevent shading on the other neighbor’s property and solar panels.
Shading caused by buildings can be a bit more challenging to address. If the building is on your property, you have the option to tear it down or alter it in a way to no longer block the sun.
If the building is not on your property, there is little a homeowner can do. The only thing that could be done is to speak with the property owner before construction to come to a mutual understanding, or agree to a solar easement agreement as explained above.
Roof obstructions normally don’t cause very many shading issues. Vents are normally thin enough not to cast much of a shadow, or they can potentially be rerouted to prevent shading. Skylights are normally very shallow and cause little to no shading. Chimneys, while sometimes large, are normally built around in a way to minimize or eliminate shading problems.
To learn more about installing solar panels around chimneys, vents, and skylights, read our blog article on the topic.
INVERTERS & GROUND MOUNTS REDUCE SOLAR PANEL SHADING ISSUES
Another solution to solar panel shading is through equipment and placement choices. This includes the type of solar inverters you choose, as well as installing ground-mounted solar panels.
The type of inverter you chose to pair with your solar panels can have a large impact on the production of your solar panels. This is especially true if your solar panels will experience shading.
The most common type of solar inverter is the string inverter. String inverters work by connecting a string of solar panels to one single inverter, which converts the total DC input into AC output.
The downside of a string inverter is that if one solar panel is shaded, the energy output of the whole string of solar panels is reduced. This greatly reduces solar output, and therefore string inverters are not recommended for areas with shade.
That’s why power optimizers or microinverters are a better alternative.
Power optimizers are located on the back of each solar panel, and they work in conjunction with a string inverter to convert DC to AC. They do this by conditioning the DC electricity from each panel and sending that conditioned DC to the string inverter to convert to AC electricity.
Because power optimizers can condition the DC electricity produced by each individual solar panel, they can decrease the impact of shading on individual panels. If one solar panel is partially shaded, it will not degrade the output of the entire string as would a simple string inverter setup.
Microinverters work by converting DC to AC directly from the back of each solar panel. No string inverter is needed because each microinverter takes care of DC conversion on the spot.
Because each microinverter is handling the conversion from DC to AC on each panel, that allows the system to be minimally impacted by shading on individual panels. If shade covers one panel, only that panel will produce less power output as opposed to the whole system output decreasing, as in a string inverter setup.
To learn about the different types of solar inverters, check out our blog post on the topic.
Another solution to solar panel shading is to consider ground-mounted solar panels.
If your roof is too shaded for solar panels, a ground-mount can allow you to position the solar panels wherever is convenient and sunny.
Because ground-mounted solar panels are not bound by the limitations of your roof, they can be installed at nearly any location on your property. This will allow you to avoid shading, as well as position the solar panels in a location that is potentially more convenient and more productive.
To learn more about the pros and cons of ground-mounted solar panels vs rooftop solar panels, check out our blog post on the topic.
SOLAR PANELS SHADING ANALYSIS
If you are unsure if your roof is too shaded for solar panels, the best thing to do is request a solar analysis from Green Ridge Solar.
Green Ridge Solar uses advanced solar analysis technology to take satellite images and analyse the amount of shade your roof receives. With this information, we can create a customized solar analysis that shows where your solar panels can be located, as well as your expected energy savings over time.
Contact Green Ridge Solar today for your free solar panel shade analysis.
SHOULD YOU INSTALL SOLAR PANELS?
Solar panels can provide homeowners the opportunity to save loads of money on their energy bills. This is true even for houses with mild to moderate shading.
To find out if solar panels make sense for you, contact Green Ridge Solar.
We can provide you with a free solar analysis that shows where your solar panels can be located, how much energy you can produce, and most importantly, how much money you could save.
Contact Green Ridge Solar today, and find out how solar energy could save you money.