Installing a commercial or residential solar system is a great way to save money and contribute to creating a more sustainable society. By converting sunlight into electricity, you cut your electricity bills while also reducing carbon pollution emitted during the burning of traditional fossil fuels.
While solar panels are a great way to accommodate these goals, it's important that these modules have a direct and unobstructed source of light shining down on them at all times. Any sort of obstruction to the photons hitting the solar cells reduces the overall efficiency of the system and ultimately lowers the energy output.
It's important for all solar panel end users to ensure they've taken the necessary pre- and post-installation steps to eliminate as much shading as possible to facilitate as much solar energy generation as possible.
Why is shade bad for solar panels?
A high level of shading that reduces the energy output means that it will take longer to recoup your return on investment. In addition, too much shading means the system isn't converting as much sunlight as possible and your electricity demand may need to be met with traditional sources of energy generation, thereby contributing to greater amounts of CO2 emissions.
Essentially, if there's too much shading that's blocking sunlight to the solar panels, it begs the question: What's the point? End users operating solar panels want to ensure these major investments are generating as much energy as possible. Not obtaining the highest levels of electricity might prolong the ROI much longer than it should take.
Think of a string of solar panels as a pipe. In this case, the solar power running through the panels are like water flowing through the pipe. Using this metaphor, shading is analogous to a clog in the pipe, as the output of the entire string can be reduced to close to nothing if a shadow lingers over the solar panels. Worse, shading on even just one cell could potentially drop the entire panel's output to near zero.
In addition to shade, dust particles can also lower the overall efficiency of a solar panel. End users in areas with a high concentration of dust and sand need to remain vigilant in their efforts to keep their panels clean from all of this debris.
Thankfully, there are ways to combat this drag on energy generation. Consider these five tips for handling PV system shading:
1. Plan before you install
This should go without saying, but it's always worth repeating, just in case. It's important to carefully plan the layout of the solar panels prior to their installation and site the array in a location where little to no shade will fall. In addition to ensuring the area is free of potential shading obstacles, such as trees, chimneys and other buildings, it's also wise to try to envision what the area will look like in 15 or 20 years. Since solar panels have a lifetime warranty of between 25 and 30 years, there's enough time for a sapling to grow into a big leafy tree that has the potential to shade your solar panels. This also includes watching where a tree's shadow falls throughout the entire year. As the seasons change, the sun will shine from a different angle in the sky, which can greatly influence what parts are shaded and when.
2. Consider a ground-mounted installation
Sometimes chimneys, gables, HVAC systems or other design features of the building simply do not leave a place to install a solar panel array without risking a considerable amount of shading. In these instances, the U.S. Department of Energy and National Renewable Energy Laboratory suggested installing a ground-mounted system or freestanding PV array instead. Although this doesn't help those who have already installed a solar panel on a roof and are now experiencing shading, it can provide a sensible solution to those with shady rooftops.
3. Do some yard work
Sometimes the problem with shading stems from a tree that grew larger than anticipated and its branches are now blocking sunlight from shining on a rooftop solar installation. In a situation like this, it's easy to simply trim back some branches and expose the solar panels to the sun's rays. While you can easily cut some branches by using a ladder and shears, some trimming jobs need to be handled by professional landscapers. Be sure to implement safety precautions if undertaking the work by yourself.
4. Use an easement
Obstacles other than tree branches can potentially be more of a hindrance. A new building going up next door can cut off sunlight to the panels and create a drag on energy production. As noted by NOLO, depending on which state you live or operate in, you may be able to protect your solar access through the creation of a "solar easement." Whereas a traditional easement would allow a pipe from your house to run underneath your neighbor's property, a solar easement restricts what a neighbor may build or grow on his or her property that would occupy airspace blocking sunlight from reaching your solar panels. This ensures you will have access to sunlight even if the neighbor sells his or her land. Although solar easements are largely voluntary, having one of these agreements in place and on file with a local county clerk can guarantee unfettered sunlight shines down on your solar panels year round.
5. Take advantage of a smart PV system
Sometimes, no matter how you try to avoid it, shading happens. Since shading on a single panel can impact the performance of the entire string of panels, installing a smart modules solution allows each panel to operate at its maximum power while eliminating mismatch loss on a single string.
In areas where shading will potentially be an issue, Trinaflex enables selective deployment of Trinsmart modules to these areas to avoid a drop in panel efficiency and optimize the system's energy generation. Trinaflex lets you install Trinasmart, Trinaswitch and standard modules all on the same string, which creates additional flexibility to maximize the number of panels on the roof while also avoiding any potential shading areas.
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