Solar energy is a growing part of the global energy mix. But even in sunny regions, one issue continues to limit performance i.e. shading. Whether caused by nearby objects, weather changes, or layout limitations, shading can lead to real energy losses in a photovoltaic (PV) system.
Shading is one of the most common and underestimated challenges in solar photovoltaic (PV) systems. Even minor obstructions like trees, poles, or nearby buildings can lead to significant shading losses in solar panels over time. As solar adoption continues to rise, especially in space-constrained or complex environments, managing shading losses has become essential for ensuring long-term performance and financial returns.
Among the various solutions available today, bifacial solar modules are gaining attention for their ability to capture light from both the front and rear sides, making them a practical and efficient choice for improving energy yield in partially shaded or diffused-light conditions.
Understanding Shading Losses in PV Systems
What are shading losses?
Shading loss occurs when sunlight is blocked from hitting a solar panel. This is not just a surface-level issue. Even a small shadow on part of a solar panel can affect the entire row of panels if they’re wired together. The result is a solar energy loss due to shading that’s often greater than it seems.
Types of shading
- Permanent/static – caused by nearby buildings, trees, poles, etc.
- Temporary/dynamic – caused by cloud cover, moving objects, or seasonal shifts in the sun’s position.
How shading affects energy output
Because of how solar cells are connected in a panel, even a shadow on just one cell can reduce the current through the entire circuit. This is why a 10% shaded area can sometimes lead to a 30-40% drop in output for that panel.
Traditional Strategies to Minimize Shading Losses
Here’s how traditional systems try to limit shading impact:
- Smart site planning – placing panels away from potential shade sources
- Row spacing and tilt – designing layouts to avoid panel-to-panel shading
- Bypass diodes – built into modules to allow current to “skip” shaded cells
- DC optimizers and microinverters – help each panel perform independently so that one shaded panel doesn’t pull down the others. While these methods help, they come with added cost and complexity. This is where bifacial modules come into play as a more passive, yet highly effective, solution.
What Makes Bifacial Modules Different
Bifacial modules capture light from both the front and rear surfaces. Traditional (monofacial) panels only use the front side. The rear of a bifacial module picks up reflected light from the ground or nearby surfaces. This helps recover some of the energy that would have been lost due to front-side shading.
Why this matters
In environments where full sunlight isn’t guaranteed like industrial rooftops or areas with partial obstructions, bifacial panels can help maintain output consistency by using indirect light.
How Bifacial Panels Recover Shading Losses
Several factors help bifacial modules offset shading losses:
- Ground reflectivity (albedo): White gravel, concrete, or painted surfaces bounce light onto the rear of the panel
- Panel height and tilt: Raising the panels helps more light reach the back.
- Use of tracking systems: Solar trackers improve both front and rear exposure throughout the day
- Include Weather Impacts: Light diffused through cloud cover still benefits bifacial panels slightly — note this as an advantage in monsoon-prone or temperate zones.
Studies show that under partially shaded conditions, bifacial panels can recover anywhere from 5% to 20% more energy compared to monofacial systems.
Design Strategies to Maximizing Bifacial Panel Efficiency
To get the most from bifacial modules, certain solar panel optimization for shading choices can make a big difference:
- Use high-albedo ground materials
- Elevate panels by at least 0.5–1 meter
- Optimize tilt angles to balance front and rear exposure
- Space rows to prevent mutual shading
- Pair with tracking systems, when possible, especially for utility-scale installations
These choices don’t require drastic redesigns but offer meaningful returns in overall system performance.
Economic Value of Bifacial Systems
Choosing bifacial modules over traditional ones may come with a slightly higher upfront cost, but the lifetime gains often justify the investment:
- Higher energy yield: More kWh per kW installed means better ROI
- Better land use: Especially important for ground-mount systems where space is limited
- Reduced payback period: Some studies show bifacial systems recover costs 6-12 months faster than monofacial systems
- Grid contributions: In areas where feed-in tariffs or net metering exist, additional energy translates to more savings or revenue
For commercial and utility-scale projects, even a 5-7% gain in energy can translate into lakhs (or more) in recovered revenue over the system’s life.
Real-World Performance Evidence
- A 2023 study in Clean Energy journal found that bifacial solar panels produce nearly 19% more energy per year than traditional one-sided panels when both face the same shading challenges. The researchers discovered that light hitting the back side of these panels helps keep energy production steady even when shadows block sunlight from the front.
- Testing by the National Renewable Energy Laboratory (NREL) showed that bifacial solar panels can produce 9-20% more energy by capturing light from both sides. This extra power helps offset losses when shadows fall on the front of the panels, making these systems more reliable throughout the day.
A Smarter Way to Handle Shade
Shading losses have always been a limiting factor in solar performance. While traditional design strategies have improved things, bifacial modules offer a built-in way to offset these losses. Their ability to harvest light from both sides helps ensure more consistent performance, especially in variable conditions.
At GREW Solar, we design and manufacture high-efficiency bifacial modules that
are built to thrive in real-world environments. From reflective rooftops to utility scale projects, our modules help deliver dependable power, even when the sun’s path isn’t perfect.
Looking to make the most of every ray, front and back?
Contact us to explore how we can brighten your future with our solar solutions. Partner with GREW Solar to explore bifacial modules that offer better performance and better economics.
Connect with us to learn more about our products or request a quote
Frequently Asked Questions [Faqs]
- What are shading losses in solar panels?
Shading losses occur when part of a solar panel is blocked from sunlight, reducing the panel’s ability to generate power. Even partial shading impacts overall system output. - How do shading losses in solar panels affect the performance of a PV system?
Shading can disturb the flow of electricity through the panel, lowering voltage and power output. In string-connected systems, even one shaded panel can reduce the efficiency of the entire array. - What are bifacial solar panels, and how do they differ from traditional panels?
Bifacial solar panels generate power from both the front and rear sides. Unlike traditional panels that only capture direct sunlight, bifacial modules also absorb reflected light from the ground or nearby surfaces. - How do bifacial solar panels help mitigate shading losses?
Since bifacial panels can absorb light from both sides, they can still generate additional energy even if the front side is partially shaded, reducing overall performance loss. - What is the role of ground reflectivity (albedo) in bifacial panel performance?
Higher ground reflectivity increases the amount of light reaching the rear side of bifacial panels, improving their energy generation. Surfaces like white gravel or concrete enhance this effect. - Can bifacial solar panels be used in areas with temporary shading, such as cloud cover or moving objects?
Yes, bifacial panels are suitable for such areas as they can capture diffuse and reflected light, helping maintain performance during intermittent shading conditions. - What factors can maximize the performance of bifacial solar panels?
Optimal tilt angle, elevated mounting, high ground reflectivity, and minimal rear-side shading are key factors that improve bifacial panel output. - What are the economic benefits of using bifacial solar panels?
Bifacial panels can produce more energy from the same footprint, improving land-use efficiency and lowering the levelized cost of electricity (LCOE) over time. - How much more efficient are bifacial panels compared to traditional panels?
Depending on the site and setup, bifacial panels can generate 5–20% more energy than monofacial ones, with higher gains in reflective or open-space environments. - Are bifacial solar panels more expensive than traditional panels?
While bifacial panels have a slightly higher upfront cost, the increased energy generation often offsets the price difference, making them cost-effective in the long run. - Can bifacial panels be used in residential solar systems?
Yes, bifacial panels can be used in residential setups, especially when installed on reflective rooftops where both sides of the panel can capture light.
