Having a shade-free area to install solar panels is one of the most important qualifications to determine if a clean power installation will be worth it for your home.
As solar panels work most efficiently in full sunlight conditions, even a small amount of shade on your installation can cause a reduction in your system’s total performance.
To help you maximize your renewable energy investment, this article will explore the effects of shading on solar panels, before outlining what can be done to minimize any negative impacts of shade.
Do solar panels work in the shade?
Although direct sunlight is optimal for energy production, solar panels can still produce electricity in partially shaded conditions. That said, the effect of partial shading on a solar panel will reduce its potential power output at a rate based on the percentage of shaded individual solar cells, the solar panel’s efficiency, and several other factors.
Without the right equipment, wiring configurations, or necessary precautions (we will dive more into these later), shade on a single solar panel can also reduce the performance of other panels in a solar system, reducing the overall power generation. If you are concerned about partial shading on your solar panels, talk to your installer about the impact it may have on your system’s total performance.
Are there shade-tolerant solar panels?
While some will say that there is no such thing as a “shade-tolerant solar panel” there are several technologies that can help curb the adverse effects of shade on solar power production. Today, most solar panels use built-in “bypass diodes” to help partially shaded panels continue to produce electricity safely and efficiently, even if a cell (or multiple cells) is shaded.
In an industry that never stops innovating, companies such as the San Francisco-based Optivolt are working on ways to increase the shade tolerance of solar panels. According to their website, Optivolt’s patent-pending Pulse technology can replace the bypass diodes found in ordinary solar panels, delivering “up to 25 times more power” in shady conditions.
Our Top 3 Solar Panel Shading Solutions
If your property is partially shaded by trees, roof obstructions, neighboring buildings, or anything else under the sun, here are three things you can do to make the most out of your solar installation.
1. Find the best location with a solar panel shading analysis
Even before you start talking to installers, it is relatively easy to determine the best place for solar panels on your property. Using a resource such as Palmetto's solar calculator, you can instantly see a shading analysis of your property to discover the best, shade-free spots for installing solar panels.
If you are wondering how solar shade calculators work, the most important thing to remember about panel placement is that they should receive full sunlight (if possible) during peak sun hours. While a little shade on your panels close to dusk or dawn will reduce smaller amounts of solar output, harnessing full sunlight midday and early afternoon is critical for your system’s overall performance.
As such, the optimal location for solar panels installed in the United States is typically found on a southern-facing roof that receives direct sunlight during the majority of the day, every day of the year.
2. Consider module-level power electronics (MLPEs)
If you have already done everything in your control to optimize the location of your solar panels, the easiest way to boost their shade tolerance is by utilizing module-level power electronics (MLPE) like microinverters or power optimizers.
When solar panels are wired together into a traditional string inverter, one single shaded panel may reduce the performance of other connected panels, even if they are still in direct sunlight. This is because multiple solar panels wired in a “string” or “chain” may only “be as strong as their weakest link” causing overall power outputs to drop when a single panel is shaded.
To prevent such losses, MLPEs can be added at the “module level” (one per solar module or panel) to allow your solar panels to operate more independently than in a string inverter system. While power optimizers can boost panel performance alongside a string inverter system, microinverters are an alternative to string (or central) inverters and are usually installed directly beneath each panel.
3. Work with an expert
When partial shading comes into play, working with an expert to design and install your solar energy system will be the best way to optimize its performance. With an experienced solar expert by your side, you can ensure that you are maximizing your property’s space and generating the most solar power possible to save on energy bills and recoup your investment.
Occasionally, you might also be able to trim or remove trees to allow for more direct sunlight to reach your panels. If you are working closely with a knowledgeable designer, they may be able to help you calculate whether or not the increased efficiency of your solar panel system will make up the costs of hiring an arborist.
For questions about your property’s unique solar suitability, you can contact a Palmetto solar advisor at no cost or obligation. Alternatively, if you would like to jump ahead and see how the shade on your property will affect the performance and ROI of your solar panels, you can calculate your solar savings today.