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Solar 101

Do Solar Panels Work in the Shade?

Optivolt

May 15, 2023

5 min read

Solar panels have quickly become the future of energy production. Solar arrays can make use of ineffective space like a roof and turn it into an energy generator. But when a tree, building, or other obstruction shades just one portion of a panel, the entire panel's output can be rendered useless.

Most solar panels are ineffective in the shade, but a new innovation by Optivolt is changing this fact. In order to determine whether or not solar panels work in the shade, we first need to take a look at how this technology functions in the first place.

How Solar Panels Work

In order to determine if solar panels work in shade, we first need to understand how they function. As we know, photovoltaic (PV) panels convert sunlight into usable electricity. Each panel is composed of many solar cells. Sunlight causes the electrons in a cell to move from low-energy to high-energy states, which generates voltage and electric current. This process is known as the photovoltaic effect.

The solar cells in a panel are typically connected in series to achieve a high voltage. In a series circuit the voltage of each cell adds up but the current is the same throughout all of the connected components. When a cell is shaded, fewer electrons become excited and less current is generated. This leads to the rest of the connected cells being limited to the reduced output of the one shaded cell.

This phenomenon unfortunately works on a larger scale as well. When one panel in an array has reduced output due to shading, the rest of the panels are also affected (assuming that they are connected in series). These bottleneck effects explain why partial shading can have such a drastic effect on solar panel output.

Will Solar Panels Work in the Shade?

Yes, solar panels will still work under some shade. However, their output will decrease dramatically. Most solar panels utilize the same basic technology outlined above, in which the shading of even one cell will reduce the entire panel's output. If 10% of the panel is shaded, you don't just lose 10% of the power output — a panel (or an entire array of panels) can be rendered practically ineffective if just a few cells become blocked.

Best Solar Panels for Shaded Areas

Shade-tolerant solar panels are the best solar panels for shaded areas. They are a new advancement in solar technology that gather more energy in real-world, shaded conditions. Until now, nobody had been able to solve this problem at a price point that made sense for consumers. Now, Optivolt is making shade-tolerant solar panels available for both residential and RV solar systems.

optivolt shade-tolerant solar panels in campground

Optivolt’s shade-tolerant solar panels improve upon high-efficiency monocrystalline panels by embedding Pulse power electronics technology into each panel. In a traditional panel, a shadow creates a wall that blocks the flow of power through the entire panel, drastically dropping power output. Optivolt’s Pulse technology cleverly re-routes the power flow around the shadow(s) and back out, enabling up to 60X more power delivered under shade.

These solar modules are a great option for solar-powered RVs and camper vans, as these mobile setups are always in and out of shaded areas. With the limited space of an RV roof, maximizing the array's output is especially important. Flexible panels have been used in the past to try and increase solar panel real estate, but the sun often reaches these curved modules in uneven ways which leads to lower output.

For example, a small camper van or RV may have three 100W solar panels attached to their roof. In optimal summer conditions, this 300W array may generate around 1.2 kWh of power per day.

When just one cell becomes shaded by 40%, that covers just 0.37% of total solar area, yet the entire output of the array could decrease by 40% (depending on how the panels are wired together). If this shading was consistent throughout the day, the potential output would decrease to only 720 kWh. Plus, the shaded cell will generate heat and degrade at a faster rate.

When this same scenario occurs with shade-tolerant solar panels, the results are much different. The panel's shade-affected zone is the only section that experiences reduced production — the rest of the cells are able to contribute their full power. This means that the overall power output only drops by a small portion.

Avoiding Shade with RV Solar Systems

Summer RV trips usually involve searching out a shady spot in the forest — unfortunately, this means less sunlight for your RV solar panels. This could pose a problem if you use a lot of energy, but you can take a few steps to avoid running out of charge.

It's important to remember that the summer provides more sun hours than winter. So even if your panels are partially shaded by towering ponderosas for a few hours, you should still be able to capture an adequate amount of energy while the sun is overhead.

That being said, installing shade-tolerant solar panels can help you eke out every last bit of sunlight. When foliage shades a fraction of your array, it will provide much more power than other RV solar systems. This can be the difference-maker in being able to support high-powered appliances like refrigerators, water heaters, and microwaves.

solar powered rv driving and casting a shadow

Making the Most of Partial Shade

You can take various steps and precautions to reduce or eliminate the negative effects of shaded solar panels.

  • Avoid Regular Shading: If you have a choice of where to install your panels, then avoid future issues by placing them in a sunny area. Before installing your array, monitor the potential site and watch for potential shading issues. Does a chimney, building, or tree shade the area for a significant portion of the day? If so, try to identify an alternative location for your solar panels.

  • Install Shade-Tolerant Solar Panels: Optivolt has innovated new technologies to reduce the effect that shade has on a solar array. Shade-tolerant solar panels are finally bringing new ideas to a stagnant industry. With the advent of their Pulse technology, the Optivolt 100W solar panels are able to harness energy in the shade with high efficiency. This technology is essential for RV solar systems that will inevitably end up in the shade.

  • Use MPPT Charge Controllers: Maximum Power Point Tracking (MPPT) is a technology used in solar charge controllers and panels to maximize electricity generation. This technology continuously tracks and adjusts the various power characteristics to operate the panel at its maximum power point (MPP), which is calculated as a product of voltage and current. MPPT doesn’t solve the shading problem like shade-tolerant panels do, but they will ensure that the system isn’t wasting power by operating the panel at a non-ideal voltage.

  • Move Your Panels: A solar-powered campervan or RV allows for the luxury of moving panels throughout the day. An attentive camper can re-park the vehicle over the course of an afternoon to maximize the gathered sunlight. Solar arrays mounted on tiltable brackets — either automatic or manual — allow the user to adjust the angle of the panels. This could be the difference between receiving full or partial sun.

  • Be Energy Conscious: If you are experiencing a bout of cloudy weather or other shading issues, you can always attempt to reduce your energy usage until you are generating full power again. Turn lights off when they are not in use, only open the refrigerator when necessary, and use the heater only when necessary.

Conclusion

Partial shading can have drastic effects on the output of your array due to the manner in which most traditional solar panels are constructed. Since they are a series circuit, the output of the entire panel or string is brought down to the level of the weakest cells.

Optivolt has worked to solve this issue and create the best solar panels for shaded areas. Optivolt has been engineering new technologies for over five years to great success. Their unrivaled Pulse technology is now available to use in the form of a 100W solar panel, delivering up to 60x more power in shaded conditions vs traditional panels.

What steps will you take to limit the effects of shading on your solar panels?