An introduction to solar panel efficiency and performance
Table of contents
The energy efficiency of solar panels is a measurement of how effectively solar panels convert sunlight into electricity. It’s a crucial indicator of overall system performance and energy output. High-efficiency panels produce more electricity from the same amount of sunlight compared to lower-efficiency panels, making them more desirable for those looking to maximize energy production and system yield. SolarEdge power optimisers can further enhance efficiency by enabling each panel to operate independently, reducing losses from shading and mismatched panels. Solar panel efficiency is a complex topic; in this guide, we’ll explore some of the basics.
How efficient are solar panels? Factors influencing efficiency
Several key factors influence the efficiency of solar panels, including cell technology, material quality, temperature, shading, orientation, tilt angle, and spectral response. These elements collectively determine how well a solar panel can convert sunlight into usable electricity.
Spectral response
The ability of a solar panel to convert different wavelengths of light into electricity affects its efficiency. Solar panels that capture a broader spectrum of light, including infrared and ultraviolet, tend to be more efficient. This is because they can harness more of the available sunlight, converting it into usable energy. Panels with a wide spectral response are particularly beneficial in diverse weather conditions, where the quality and intensity of sunlight can vary. By capturing a broader range of light wavelengths, these panels can maintain higher energy production even on cloudy days or during early morning and late afternoon when sunlight is not at its peak.
Types of solar cell technologies
Understanding the various types of solar cell technologies is crucial for selecting the most efficient panels for your needs. The primary types of solar cell technologies include monocrystalline, polycrystalline, and thin-film solar panels. Each type has its own set of characteristics, efficiency levels, and ideal applications.
Monocrystalline solar panel efficiency
Known for their high efficiency and long lifespan, monocrystalline panels are made from a single crystal structure. These panels are ideal for areas with limited roof space because they provide the highest power output per square foot. The manufacturing process for monocrystalline panels involves growing a single crystal of silicon, which results in a purer and more efficient solar cell. The uniform structure allows for better electron flow, leading to higher efficiency and greater energy production. Monocrystalline panels are often more expensive than other types, but their superior performance and durability make them a popular choice for residential and commercial installations.
Polycrystalline solar panel efficiency
Polycrystalline panels are slightly less efficient than monocrystalline panels but are more affordable. They are made from multiple crystal structures and are suitable for larger installations where space is not a constraint. The manufacturing process involves melting silicon fragments together, resulting in a cell with multiple crystal structures. This process is less costly than producing monocrystalline cells, making polycrystalline panels a more budget-friendly option but these panels have largely been superseded by Monocrystalline panels in Australia .
Understanding efficiency ratings
Efficiency ratings provide a standardised way to compare the performance of different solar panels. Let’s run through some common terms and concepts you’re likely to encounter.
Peak efficiency
This is the maximum efficiency a solar panel can achieve under ideal conditions. It represents the highest percentage of sunlight that the panel can convert into electricity. Peak efficiency is typically measured in a controlled laboratory environment, where conditions are optimised for maximum performance.
Average efficiency
This is the typical efficiency a panel can maintain over time in real-world conditions. It takes into account factors like temperature fluctuations, shading, and dirt accumulation, which can affect the panel's performance. Average efficiency provides a more realistic measure of how the panel will perform in everyday use.
Temperature coefficient
This indicates how much a panel’s efficiency decreases as the temperature increases. Panels with a lower temperature coefficient perform better in hot climates because they are less affected by temperature changes. The temperature coefficient is an important consideration for installations in areas with high ambient temperatures.
Maximising efficiency through design and installation
Maximising the efficiency of your solar panel system involves careful planning and installation. Here are some key considerations.
Optimal panel placement
Panel placement is critical for achieving optimal solar panel performance. Panels should be installed in a location that receives the most sunlight throughout the day, with minimal shading from trees, buildings, or other structures. The orientation and tilt of the panels should also be optimised based on your geographical location to ensure they capture as much sunlight as possible. The reality is, you have to work with the roof you have - and if design flexibility is important, SolarEdge Power Optimisers can help. They allow each panel to work independently, enabling placement on different roof aspects and ensuring the energy efficiency of your solar panels remains high even in challenging layouts.
Regular maintenance
To maintain optimal efficiency, regular maintenance of solar panels is essential. This includes cleaning the panels to remove dirt, debris, and other materials that can block sunlight and reduce efficiency. Regular checks and repairs of the mounting and wiring systems also help prevent efficiency losses due to physical damage or wear and tear. It is best to let a licensed professional carry out this maintenance work.
Temperature effects and heat management
Understanding the impact of temperature on solar panel efficiency and implementing effective heat management strategies are crucial for maintaining high performance, especially in hot climates.
Heat reduction strategies
Using materials with high thermal conductivity for the backing of solar panels can help dissipate heat more effectively. Additionally, installing panels with enough space for air circulation behind them can reduce temperature buildup. Some newer panel designs include integrated cooling systems to further manage heat.
Selecting panels with low temperature coefficients
Choosing solar panels with low temperature coefficients is important for installations in hot climates. These panels are specifically designed to withstand high temperatures without significant drops in efficiency.
Financial implications of efficiency
The efficiency of solar panels directly affects the financial returns of a solar energy system. Here’s how higher efficiency can lead to better financial outcomes.
Faster payback periods
Highly efficient solar panels generate more electricity, which can significantly reduce your energy bills or even earn you money through feed-in tariffs where excess electricity is sold back to the grid, although these feed-in tariffs are generally being lowered across Australia. This increased energy production may lead to faster payback periods for the initial investment in solar technology.
Real-world performance vs. lab conditions
The efficiency of solar panels can vary significantly between ideal laboratory conditions and real-world environments. Understanding this difference can help set realistic expectations for solar energy production.
Factors affecting real-world performance
The average efficiency of solar panels in terms of real-world performance may be lower than under laboratory conditions due to various factors such as partial shading, dust, and bird droppings, which can obstruct sunlight. Weather conditions like cloud cover, humidity, and high temperatures can also affect efficiency. This is where a power optimiser can help. SolarEdge power optimisers mitigate these issues by performing Maximum Power Point Tracking (MPPT) at the module level, ensuring each panel operates at its peak efficiency despite shading or soiling. This leads to higher overall energy output and improved system performance under diverse real-world conditions.
Key takeaways
Ready to harness the power of the sun? SolarEdge uses smart panels to improve solar panel efficiency. Get in touch with one of our trusted solar installers to explore the best solar solutions tailored to your needs. Got another question? Don’t hesitate to contact us directly.
