November 8, 2022 / Solar Panel

How Efficient Are Solar Panels in Cloudy Weather? Do They Work?

Solar energy has emerged as a centrepiece of sustainability. But many wonder about its efficacy under the veil of clouds. This blog explores the resilience of solar panels in the case of overcast skies. While sunlight is their lifeblood, modern panels are adept at harnessing even the diffused light on cloudy days. This ensures a steady energy flow.

We will explore the factors that impact their efficiency. We will also check out practical strategies to get better performance regardless of the weather’s whims.

Join us as we shine a light on the capabilities of solar panels in cloudy conditions.

Factors that affect solar panel efficiency

Only a fraction of the sunlight that reaches a PV cell is converted into electricity; the majority is lost. Several factors in solar cell design contribute to limiting a cell's capacity to convert received sunlight. Incorporating these factors into the design process can help achieve higher efficiencies.

1- Wavelength - Light is made up of tiny energy packets called photons. They are of different sizes and strengths. Sunlight contains a mix of these photons. These can range from ultraviolet to visible light to infrared. When sunlight hits a solar cell, some photons bounce off. But others tend to go through. Some of the photons that get absorbed turn into heat. The rest have just the right amount of energy to release electrons from their atoms, creating electricity.

2- Recombination - In a semiconductor, just like a solar cell, electric current is found to flow when the charged particles, known as the “charge carriers,” travel through the material. An electron, which is negatively charged, is one such carrier. The other type is called a "hole," which acts like a positively charged carrier. Sometimes, when an electron meets a hole, they combine and cancel out their charges, reducing the electric current. This happens in two ways –

• direct recombination, where light-created electrons and holes meet and emit light,
• and indirect recombination, where electrons or holes encounter something that makes them combine more easily and release heat instead of electricity.

3- Temperature - Solar cells work better when they are at the right temperature. When it gets hot, the material in the solar cell changes. This causes a small rise in current but a significant drop in voltage. Also, excessive heat can damage the solar cell, impacting its durability. Hence, it is important to prioritise effective thermal control to maximise the durability and efficiency of the panel and cells.

4- Reflection – To enhance the efficiency of cells, you must minimise the amount of light that reflects away from them. For instance, 30% or more of incident light is reflected by untreated silicon. Using a textured surface and an anti-reflection coating, you can easily decrease reflection. Once highly efficient, the cell will appear either dark blue of black in colour.

How These Panels Generate Electricity in Cloudy Conditions

Even in cloudy conditions, solar panels can produce electricity. They do so by harnessing both direct and diffused sunlight. Photons in sunlight, for instance, possess energy. So, when they strike solar panels, some are absorbed while others reflect off. The absorbed energy generates heat or separates electrons from atomic bonds. In turn, producing charge carriers and electric current.

Despite reduced sunlight intensity, modern panels are designed with high sensitivity. And this is why they are able to capture and convert available light effectively. This technical adaptation ensures consistent power generation. Thus preserving the investment in solar energy. As an investor, you are provided with a sustainable source of electricity for your daily needs.

Effect of Cloud Cover Duration on Energy Production

The duration of overcast skies can notably impact the creation of solar energy. Brief cloud cover may minimally affect output. The reason is that solar panels continue to draw energy from diffused light. However, prolonged overcast conditions can lead to a noticeable decrease in electricity generation. One key point to note here is that while production dips, it doesn’t halt entirely. Solar panels are still operational and contribute power. Of course, this happens at reduced levels. This resilience underscores the viability of solar energy as a reliable source throughout the year.

Strategies to Maximize Solar Panel Efficiency During Cloudy Weather

During cloudy weather, you should consider these three strategies:

- Enhanced Maintenance – It is prudent to clean solar panels regularly. Such action ensures maximum light absorption. Periodic maintenance comes in especially handy when sunlight is limited.

- Energy Storage – You can think about investing in a robust battery system. It will store excess energy generated on sunny days. This stored energy can be used during cloudy periods.

- Smart Inverters – You can also use advanced inverters that optimize energy conversion from the solar panels. Doing so makes certain that you get the most out of the diffused light available during overcast conditions.

You can apply these strategies to significantly bolster your solar panels’ performance, even when the skies are grey.

Fine-tuning Solar Panel Installation for the Most Sun Rays

The amount of sun rays hitting the panels dictates its ability to generate energy. Here are four key points to think about:

- Site Assessment: You need to carry out a thorough analysis of the installation site. Doing so will help you identify the sunniest location. The ideal place would also be free from obstructions like trees or buildings.

- Panel Tilt: The next step will be to adjust the tilt angle of your panels. The idea is to match your latitude. During summer, a lower angle is ideal. Similarly, a steeper angle is better in winter. This entails tweaking the angle at which sunlight hits the panels throughout the year.

- Orientation: Consider positioning the panels to face the true south in the Northern Hemisphere or the true north in the Southern Hemisphere. This will result in maximum sunlight exposure.

- Shading Analysis: Solar panel installation experts can use tools to predict potential shading. You can also reposition panels or trim obstructions to ensure consistent sun exposure.

When you focus on these aspects, you can significantly enhance the efficiency of your solar panel installation.

Use of Tilted or Tracking Mounting Systems

You would hear these terms a lot when you discuss solar panel performance. Tilted and tracking mounting systems are advanced solutions that significantly enhance the efficiency of solar panels. Tilted mounts are fixed at an angle to catch more sunlight, especially during peak sun hours. Tracking systems, on the other hand, are dynamic. They will move with the sun’s trajectory all day to maximize exposure.

Here are some points to consider for these systems:

1 - Space Efficiency: Tracking systems, especially dual-axis trackers, require more space between rows of panels to avoid shading as they move. This can be a limiting factor if the installation area is restricted. You need to achieve a fine balance of the increased energy output against the space needs and likely shading issues.

2 - Maintenance: Moving parts in tracking systems can wear out over time. These may require more maintenance than fixed systems. Regular inspections and servicing are necessary to ensure the tracking mechanisms function correctly and efficiently. This may add to the operational costs. However, the increased energy production can offset these expenses over time.

To conclude

This was a detailed analysis of how solar panels work. It covered the ability of these panels to generate electricity even in overcast conditions. We also saw how to tweak the panel angle and position with a single aim – to get the most sunlight coverage. As a result, you can use this knowledge and extract the most optimal performance from your solar panel setup. Make sure to connect with a reliable expert for the installation process and configuration work.

References

https://www.solvingsolar.com/panel-orientation-and-tilt-for-maximum-solar-panel-efficiency/

https://www.forbes.com/home-improvement/solar/best-angle-for-solar-panels/

https://pvcase.com/blog/fixed-tilt-vs-tracker-system-comparison-for-ground-mounted-pv-systems/