With so many options for clean and renewable energy, many people have turned to solar panels as the primary choice for powering their homes. To make the most the most out of your solar panels purchase, the key factor to focus on is how efficient they will be. Thankfully there are several metrics used to measure efficiency so you can be confident that you’re getting the right panels to suit all of your needs.

How Solar Panel Efficiency Is Measured

Solar panel efficiency measures any given panels’ ability to convert sunlight into electricity. If a solar panel has 15% efficiency, then that means it is capable of converting 15% of the absorbed sunshine into energy, with around 17-19% efficiency being the average for most panels in residential use today. However, recent innovations have more than doubled this efficiency, and the new more efficient solar panels are going to make their ways into household use in the coming years. Factors such as the environment and the panel’s individual materials play a role in determining a panel’s maximum efficiency. Thanks to solar panels being a highly competitive market in a booming industry, the efficiency of panels are only raising year by year with costs lowering on the consumer side, dropping as much as 50% since 2014.

What Determines Solar Panel Efficiency


The major factors that go into solar panel efficiency are the materials they’re made of, along with how much sunlight is absorbed into energy instead of refected off. In the case of the materials, most panels are either monocrystalline, where solar cells are made from a single source of silicon, polycrystalline, where many cells are melted together, or thin-film, which are flexible and lower cost, but degrade much quicker.

Monocrystalline panels tend to be more efficient and are the most widely used panels by consumers today. As each solar cell is formed by a single crystal, the flow of electricity is uninterrupted on account of electrons having more room to move freely. This results in greater efficiency for the panel as a whole.

Polycrystalline panels, on the other hand, are less efficient because each cell is made up of many crystals that impede movement for electrons. Less freedom to move results in a lesser flow of electricity. The trade-off is usually a lower price point for polycrystalline panels.

Currently most Monocrystalline panels deliver about 22-27% efficiency, while Polycrystalline solar panels typically range between 15% and 22%. Thin-film panels are made up of many more materials but as they currently lag behind in efficiency, they are mostly used in large-scale solar farms.


Another major factor in determining efficiency is reflectance, or how much a solar panel reflects sunlight away versus how much is being absorbed for use as energy. The greater the amount of sunlight being taken in and the lesser being bounced off results in greater efficiency. Anti-reflective coating and substances are widely used on solar panels today to help mitigate the amount of light reflected off.

Environmental Factors

Other determinants in the efficiency of panels are the various environmental factors where they are installed. Shading from nearby buildings, roof slant, dirt build-up, and direction of the panels all have effects on a panel’s ability to perform in some way, and steps like clearing surrounding foliage can go a long way in raising efficiency. It’s important to take location factors into consideration when choosing where to install panels for maximum output.


As more people every day seek to save costs, reduce their carbon footprint, and get the most out of their energy use, many have shifted over to solar panels. With rapidly improving technology and ease of availability, it’s easy to recognize how the increasing efficiency of solar panels makes them attractive for more and more homeowners.