With rising electricity costs and growing environmental concerns, more and more homeowners and businesses are choosing solar power as a sustainable source of electricity. According to the U.S. Energy Information Administration (EIA), renewable energy will account for a quarter of U.S. electricity generation for the first time in 2025. In particular, advances in solar panel design technology have dramatically improved the efficiency of solar panels, allowing them to generate more electricity in the same space and reduce costs.
Improving the efficiency of solar panels is critical for both individuals and businesses. In this article, we will show you how to improve the efficiency of solar panels.
What is solar panel efficiency?
Solar panel efficiency is the ability of a solar panel to convert sunlight into usable electricity, expressed as a percentage. For residential systems, the average efficiency of a typical solar panel is about 20%. This means that 20% of the sunlight hitting the panel is converted into electricity, while the remaining 80% is either reflected, absorbed as heat, or lost to other factors.
Several factors affect the efficiency of solar panels, including the quality of the materials used (e.g., monocrystalline or polycrystalline silicon), the design of the solar cell, and external conditions such as temperature and shading. Advances in modern solar technology have greatly improved efficiencies, with some high-quality solar panels exceeding 22% efficiency.
Monocrystalline Solar Panels
- Efficiency: 18% to 22%
- Considered the most efficient type of solar panel available, they are made of high-purity silicon, black, and suitable for roofs with limited space.
Polycrystalline Solar Panels
- Efficiency: 15% to 18%
- Polycrystalline panels are slightly less efficient than monocrystalline panels but are more affordable, blue, and suitable for homes on a budget.
Thin-film solar panels
- Efficiency range: 10% to 13%
- Thin-film solar panels are lightweight and flexible, but less efficient and are typically used for commercial projects or special installation scenarios.
| Solar Panel Type | Efficiency (%) | Price (USD/W) |
| monocrystalline solar panels | 18-22% | 2.50-3.50 |
| polycrystalline solar panels | 15-18% | 2.00-3.00 |
| thin-film solar panels | 10-13% | 1.50-2.50 |
Cell Efficiency vs. Module Efficiency
It is important to note that the efficiency of an individual solar cell is not the same as the efficiency of the entire solar panel (module). While solar panels typically have efficiencies of around 15-20%, in some cases solar cells can achieve efficiencies of up to 42%. When evaluating solar panels, it is important to distinguish between cell and module efficiency.
Solar cell efficiency: This measures how efficiently an individual solar cell converts sunlight into electricity. It is calculated by comparing the electrical output of the cell with the solar energy received under standard test conditions (typically 1000 watts per square meter of irradiance).
Solar panel module efficiency: Module efficiency, on the other hand, takes into account the overall performance of the entire solar panel (made up of multiple solar cells). It takes into account factors such as inactive areas (such as gaps or edges between cells) and any losses in the connections between cells.
Why is solar panel efficiency important?
When choosing solar panels, the first question that comes to our mind is: how much sunlight can solar panels convert into electricity? Efficiency is a key indicator because it directly affects how much energy a solar panel can produce. For users, higher efficiency means:
Generate more power in limited roof space
High-efficiency solar panels are ideal for limited roof space. It produces more electricity in the same area as solar panels. For example, for the same area of a 200W solar panel, a 20% efficient panel will produce more electricity than a 13% efficient panel. Choosing a more efficient solar panel allows you to maximize your energy output without the need for a large installation.
Pay back your investment costs faster.
Typically, efficient solar panels are also of superior quality and will produce more electricity over their lifetime, which means more savings on your energy bills. We recommend that homeowners purchase solar panels that are at least 20% efficient or higher, and statistics show that homeowners with high-efficiency solar panels can save between $10,000 and $30,000 over 20 years.
Reduced installation costs
High-efficiency panels require fewer units to meet your energy needs, which can reduce installation costs. Fewer panels mean less labor, fewer mounting hardware components and less wiring. Over time, this translates into significant savings.
Why 100% efficient solar panels are unlikely？
Let's start with solar cells.
The efficiency of a solar panel depends on the performance of its weakest link, the cell. Solar cells are made from semiconductor materials such as silicon and convert photons of sunlight into electrons to produce electricity. The efficiency of a solar cell is the ability of the panel to capture energy from the photons.
However, not all photons are absorbed: some may be reflected when they touch the surface of the solar panel. Other photons may pass through the solar panel without being absorbed, again without being converted into electricity. Still, other photons are absorbed and converted into heat rather than directly into electricity. These processes result in some loss of energy. Some of the remaining photons will excite the photoelectric effect, which converts the energy of the photons into the kinetic energy of the electrons, thus generating electricity.
Solar cell design is an important goal in the field of solar technology. Scientists and engineers are working to improve the following factors to increase efficiency.
Material type: Monocrystalline silicon panels are typically more efficient than polycrystalline silicon panels.
Wiring and busses: Cells with multiple busses and passivation help to capture and transfer power efficiently.
Reflection: Minimising the amount of light reflected by the cell is also an important factor in efficiency. For this reason, cells treated with anti-reflective coatings perform best.
Researchers are also exploring new solar cell technologies, such as chalcogenide solar cells and polycrystalline silicon solar cells, which promise to further increase the efficiency of solar panels. But there will never be a way to make cells that are 100% efficient!
How to make solar panels more efficient?
High-efficiency solar panels are always expensive. If you have limited space, you can choose other configurations and take some measures to increase solar panel efficiency.
Choosing the right solar system
The efficiency of the solar panels is also an important factor in determining the efficiency of the whole system. It is important that you fully understand your energy needs so that you can make informed decisions about how to use these devices more efficiently. This will reduce your overall consumption.
Ensure that the panel is free of debris.
Dust and other debris that accumulate on the surface of the panel can affect light transmission and absorption. Less sunlight will reach the solar cells and the amount of electricity generated will decrease. Many manufacturers recommend that you clean your panels at least twice a year. Even if your system is located in an area where it rains frequently, all panels should be checked regularly for bird droppings, leaves, pollen, ash, and other contaminants and residue.
Some manufacturers are developing ceramic coatings for solar panels to reduce the amount of dust and other debris that covers the panels.
Cleaning solar panels properly
It's important to clean your solar panel correctly; the wrong tools and methods can shorten its life. Generally, solar panel warranties do not cover damage caused by incorrect cleaning methods. Here are some general guidelines to follow:
- Choose the right time: The best time to clean solar panels is in the morning or evening. Don't do it when the panels are very hot, as drastic temperature changes can cause cracks in the panels.
- Avoid using sharp tools: Use a soft cloth, sponge, or soft brush for cleaning as they will not cause scratches.
- Use the right cleaner: Choose a mild cleaner, such as one mixed with warm water or one specifically designed for solar panels, and avoid corrosive or abrasive cleaners.
- Avoid high-pressure water: Avoid washing solar panels directly with a high-pressure water gun or water jet, as this can damage the seals and circuitry of the panels.
- Clean carefully: Ensure that the entire surface of the solar panel is thoroughly cleaned, including the edges and connectors, to ensure that the entire surface can fully absorb sunlight.
- Check for damage: During the cleaning process, be sure to inspect the solar panel for any damage or anomalies, such as cracks or breaks, and repair or replace them immediately.
In the previous article, we discussed the detailed steps for cleaning solar panels.
Avoid installing solar panels in the shade.
Solar panels can make the most of the sun's energy by converting it into electricity in places where there is plenty of sunlight. Shading can significantly reduce the efficiency of your solar panels. If your solar panels are connected in a string, a single shaded panel can reduce the output of the entire array.
In addition to avoiding installation in the shade, be careful to avoid shading from trees, buildings, or other shading objects. It can be difficult to completely avoid shading when installing solar panels. To get the maximum number of sunlight hours and light intensity for your solar panels, try to choose a mounting location that ensures the maximum amount of direct sunlight.
Get a professional installation.
If not connected correctly, solar panels can experience voltage and current problems that can affect their durability and productivity. Professional installers have the experience and expertise to ensure that solar panels are correctly installed in the most suitable locations for maximum sunlight and efficiency.
Topbull offers high-efficiency solar solutions
We understand the importance of solar panel efficiency, which is why we offer state-of-the-art solar panels designed to maximize energy production and deliver long-term value. Here's what sets our products apart:
Industry-Leading Efficiency
Our monocrystalline solar panels are up to 22% efficient, ensuring you get the most out of every ray of sunlight. Whether your roof is small or large, our solar panels provide unrivaled performance.
Durability and Reliability
Our solar panels are made from high-quality materials that can withstand harsh weather conditions, from heavy snowfall to high winds. They have a lifespan of more than 25 years, providing reliable energy for decades.
