Compared to the previous generation, this new generation is miles ahead regarding sustainable living. They are conscious about everything they purchase and consume. This increased consciousness plus the advancements in technology is why renewable energy is now the new trend.
While the first commercial solar-powered panels were created in 1881, they were highly inefficient. During the 1980s and beyond, people got to see them being used in calculators. However, the residential use of solar panels is quite recent. It began gaining traction in the 2010s. The rising fuel costs developed an interest in solar energy, leading to more R&D in the technology.
Now, the investment requirement in the system is decreasing steadily while efficiency is increasing. According to a research study, the efficiency of solar panels has increased by 5% in the last 5 years. It has gone up from 17.8% to 23%. But the big question is: are solar panels effective without direct sunlight?
Today’s solar panels can still generate electricity in all kinds of weather and even low light. Soon enough we will have solar panels that don’t need direct sunlight too.
This article delves into the factors that influence solar panel performance. It also explores some tips that can help residential and commercial solar panel users maximize the efficiency of their solar panels.
How Do Solar Panels Work?
What we commonly know as solar panels are also known as photovoltaic (PV) or solar PV panels. These panels are made up of semiconductor materials. While there are a number of semiconductor materials like silicon, boron, carbon, arsenic, etc, the most commonly used is silicon. However, now Copper indium gallium diselenide (CIGS) is also being used to create thin film solar cells.
Before we get onto the concept of how these panels work, there’s one other important thing to know – the properties of light. Light, be it in any form, is made of particles called photons. These particles are bundles of the electromagnetic field and carry a specific amount of energy.
When the particles of light, or photons hit the semiconductor material, the energy from it knocks an electron from its bond. The dislodged electrons of the photovoltaic cells produce an electric current that we can call solar energy. This entire process is called the photovoltaic effect.
However, the photovoltaic effect alone doesn’t yield usable electricity. The electric current at this point is direct current. For use in residential sockets, it needs to be converted to an alternating current. This is where the system’s inverter comes in. Storing the electricity requires a solar battery. How the battery storage works will be addressed in another article.
So, in short, solar panels work using the principle of the photovoltaic effect. They just need photons to start working and producing direct current.
Solar Panel Performance in Low Light Conditions
Solar panels are designed to work optimally in direct sunlight because they need photons with enough energy to make the electrons move. However, the advancement in technology has allowed solar panels to work in low-light and cloudy conditions as well. While the efficiency in low-light might not be as high, it is still a huge breakthrough in the world of solar technology.
The specific characteristics of the solar panels, especially the use of the semiconductor material are what allow it to perform in low-light. However, the angle of incidence and the intensity and quality of light are also some contributors towards the efficiency of a solar panel.
Do Solar Panels Work on Cloudy Days?
In areas that get a lot of rain, a common concern is: are solar panels effective without direct sunlight on cloudy days.
The good news is that solar panels do work when there is an overcast. While the clouds block out the sunlight, they do scatter the light.
This means that the photons from the sunlight are diffused. Their energy is lesser than the energy of the photons from direct sunlight. Still, when they hit the solar panels, especially efficient ones, they can be used to generate electricity.
How efficient the panels are on a cloudy day cannot be estimated accurately since solar panel output depends on a range of factors. The factors include the cloud cover, the type of clouds, and the overall atmospheric conditions.
Thick overcast can hamper energy production. Clouds that are about to pour down make it difficult for solar panels to knock electrons for electricity generation. On clouded days, the efficiency is between 10 to 25 percent of the efficiency on a bright, sunny day.
What Affects Solar Panel Efficiency in Indirect Sunlight?
We’ve talked about how weather conditions can affect the efficiency of solar panels. Now, let’s talk about it in terms of light and other factors:
- Light Intensity: The intensity of sunlight, whether direct or diffuse, directly impacts the amount of energy produced by a solar panel.
- Light Quality: The quality of light, such as the wavelength and color spectrum, can also influence solar panel performance.
- Panel Orientation and Tilt: The orientation and tilt angle of solar panels can affect their exposure to sunlight, both direct and diffuse.
- Panel Temperature: Contrary to popular belief, the panels don’t perform better on scorching days because higher temperatures can restrict the flow of electrons and quicken the degradation. The optimal temperature for the panels is 59°F–95°F (15°C–35°C).
- Panel Age and Degradation: Over time, the panels can degrade, leading to reduced efficiency. Regular maintenance including cleanliness and shade during intensely hot days can slow down the degradation process.
- Unclean Panels: If the panels are unclean, the cells might not be able to work efficiently on any kind of day. However, the efficiency of dirty panels might be extremely low in indirect or diffused sunlight.
How to Maximize Solar Panel Performance in Low Light
Even though the panels can perform during low-light like early hours in the day or when its cloudy, there are still some tips that can help maximise the potential:
Choose High-Efficiency Panels
The first suggestion is to opt for high-efficiency solar panels. Samso Solar’s panels boast a 22% efficiency. Compared to old panels, this efficiency is 7% higher. As a result, solar panels require daylight and not only direct sunlight.
Optimal Orientation and Tilt
At the optimal angle of incidence, the panels can perform better than otherwise. Samso Solar’s experts know exactly how to calculate the optimal tilt and orientation. Therefore, while installing solar panels, they position them in a way that gives you the best performance anywhere and in most weather conditions.
Consider Tracking Solar Systems
Solar panels generate more efficiently when they get direct sunlight. So, when you install solar panels, do consider solar tracking systems. They can be a useful system addition to automatically adjust the orientation of the panels, allowing maximum performance in both direct and diffused daylight.
Regular Cleaning
Lastly, keep the panels clean and free of dirt and debris. If the panels are covered in dust, the particles block the sunlight and limit the photons that impact the panels. Make sure you follow a safe panel cleaning guide to make sure that you’re doing it right.
Real-Life Examples: Efficiency in Different Locations
The efficiency of a solar-powered system can vary significantly based on geographic location and climate conditions. The UK can be divided into four main regions based on the climate. Let’s see what the system efficiency in each of these locations is:
- South-east: The south-eastern region consists of 9 UK counties including Kent, Buckinghamshire, Surrey, and West Sussex. The summers here are warm and dry. In the summer, panels in these regions can achieve high efficiency rates due to the intense solar radiation.
- South-west: The summers in the south-west area are warm and wet. Therefore, you will have some days when the system is working at maximum efficiency, while during the wet days, the efficiency might be low. Winters are also very wet in this region, but efficient panels can work their magic here too.
- North-west: The counties of Cheshire, Greater Manchester, and Lancashire get cool summers and mild winters. It rains heavily throughout the year which is why solar efficiency is comparatively low.
- North-east: Northumberland and Cleveland are a part of this region that experiences cool summers and cold winters. It rains steadily throughout the year. While solar panels may not be as efficient as in south-eastern regions, they can still generate significant amounts of electricity, especially during the summer months when it is clear.
Conclusion
The energy efficiency of solar is highest when they absorb high-energy photons from sunlight. However, modern panels can even perform in low light. Even though the performance in cloudy weather drops down to 10-25% of the normal output, the system still generates electricity.
However, some tips can help maximise cloudy-day panel performance too. Strategies like keeping the panels clean of dirt and debris and getting the right angle of incidence can help maximise performance. Some people also opt for solar tracking systems that keep their solar panels always facing the sun.
While these strategies are important, choosing high-efficiency panels is the most major contributor. Samso Solar can equip you with the latest solar panel technology, so whatever the weather may be, your solar panel will be working hard!
