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How Efficient Are Solar Panels?

Learn how efficient solar panels are as well as who should install solar panels on their home or business. SmartSolar.org can help you get solar energy in place.
Solar Panels
7 minutes
Written by:
Joey Cheek
Updated on:
December 2, 2022

One of the most common questions people have about solar panels is how well they will work in their home or for their business. How efficient are solar panels? Are they worth investing in? Can they really produce enough electricity to meet my needs? At SmartSolar, we can help you learn how beneficial solar panels are for your home when you take the SmartSolar quiz. Our goal is to help you ensure you get the right panels for your home. To get started, contact us now.

Understanding Solar Panel Efficiency

Solar panel efficiency isn’t a simple figure. Different solar panels will have different efficiency ratings. Typically, solar panels can produce between 15 and 22 percent of the solar energy they receive and turn it into usable energy. However, various factors play a role in that. For example, the solar panel itself may be more efficient than other panels. The orientation of the solar panels, as well as their placement of them, can play a role. Even whether there is direct sunlight or other weather conditions present can play a role in this process.

So, how do you know what to expect from solar panel efficiency? The ability of a solar panel system to turn solar radiation into actual electricity is called the performance of the solar panel. The outcome of the solar panel will ultimately define the solar panel’s efficiency.

How Is Solar Panel Efficiency Determined?

Standard Testing Conditions (STC) processes help to determine solar panel efficiency. That means that all panels are tested using the same equal environment to get a better idea of how efficient one is compared to others.

STC sets the specific temperature at which solar panels are measured at 25 degrees Celsius. Additionally, an irradiance of 1,000 w/m2 is used. This formula is the equivalent of a sunny day where the incident light hitting the solar panel's surface is a sun-facing 37 degrees with a tilted surface. By creating specific test conditions like this, it is possible to compare solar panels to each other easily.

Solar panel efficiency of 15 percent, then with a 1 m2 surface area, would produce, on average, 150 watts of power. Keep in mind this is just one solar panel and set of solar cells. Most homes will have more than one solar panel system in place, which means it would generate a significant amount of energy to meet the home’s specific needs.

Which Solar Panels Are the Most Efficient and What Are Each of The Benefits of Solar Panels?

Many factors play a role in how efficient solar panels are, but one thing not to overlook is the type of solar panel itself. Solar panel efficiency partially depends on the materials used within the solar panel itself. Which are the most efficient solar panels, then? Here is a look at some of the high-efficiency solar panels that you may have as a part of your ‘solar system.’

Monocrystalline solar panels

This type of solar panel, sometimes called a single-crystalline cell, uses the highest quality, the purest form of silicon. A complex process is used to create this type of crystal that produces a long rod, which is then sliced into thin wafers. These wafers are what make up the solar cells. These are the highest-efficiency solar panels in most STCs. These can offer solar panel efficiency of 22 to 27 percent in many situations.

Polycrystalline solar panels

This type of solar panel, sometimes called multi-crystalline cells, is a bit less efficient, ranging from 15 to 22 percent in most cases. This difference is because there is a different solar panel production process for these. The silicon itself is not grown in a single cell like it is with monocrystalline solar panels. Rather, it is done in a block of crystals. The blocks are then sliced and cut into thin wafers. This produces the individual solar cells.

Thin film solar panels

The third type of solar panel is a thin film solar panel, which has a substrate material on the top of it, such as glass, plastic, or in some cases, metal. This has very thin layers of photovoltaic material on them. Most designs of these solar panels incorporate thin films that are flexible and lightweight. The difficulty with these solar panels is that they tend to degrade faster than other types. Producing solar panels like this is less complex and more affordable, but they do not reach the same solar panel efficiency. Thin film solar panels typically have an efficiency rating of 15 to 22 percent.

One key thing to know about the most efficient solar panels is that they are getting even 

more efficient. Today’s high-efficiency solar panels are being improved repeatedly to boost their solar efficiency. The higher-efficiency solar panels are worth the investment, and over time, you are likely to see more thin-film solar panels become accessible at a lower cost.

How to Buy the Best Solar Panels

Understanding how solar panels work is critical. Choosing solar panels based on how much energy they produce is the core of getting the most out of solar cells and solar energy overall. How do you know which are the most efficient solar panels or how to buy the best pricing?

Whenever possible, aim to purchase monocrystalline panels because they are the highest efficiency solar panel currently available. However, get to know the other options on the market. As solar power becomes more readily used and solar technology improves, solar panel manufacturers will have far more options to improve these products.

There are a few key things to remember when looking for efficient panel options for your home.

  • Maximizing energy does not just mean buying a super high-efficiency system. Be sure to purchase enough solar panels to meet your energy needs. It is important to know what your power generation needs are as well. To do that, you’ll want to consider how much power you use at home consistently.
  • Location matters. As you consider the options best suited for your energy needs, remember that other factors impact overall efficiency. That includes the roof direction. If the panels can capture sunlight easily, efficiency improves. If the sunlight shining isn’t hitting the panels, though, due to shade, that reduces efficiency overall.
  • For commercial solar panels, consider not placing them on your available roof space if it is limited. Instead, consider positioning solar panels on the ground in a solar array that’s directed at the sun. Some systems will move with the sun throughout the day, increasing solar efficiency.

What’s most important is to see out higher efficiency panels that fit your specific needs. The best panels generate enough solar power to consistently meet your home’s needs. However, the cell efficiency of photovoltaic panels will range between manufacturers.

Get Started with Solar Energy Today

Even if you’re unsure if solar energy is right for you, you can take the first step in getting more information. Solar panel installation from SmartSolar is one of the most effective steps you can take now to create energy security for your home or business. Contact us now to learn more about the process.

Joey Cheek

Frequently Asked Questions

It’s common for people to have many questions about solar panels and energy in general. Our team is always available to answer your questions. Here are some of the most common questions about solar panels and solar power systems.

How efficient are solar panels, really?

While solar panels will meet energy needs for most people, they are not that efficient overall. However, it is possible to generate as much electricity as you need in nearly all situations. The key here is that solar panels do not need a lot of direct sunlight constantly to meet your energy needs in most cases. As higher efficiencies become available, you are likely to see the number of solar cells needed to power homes or businesses drop.

Are 100% efficient solar panels possible?

There are no solar panels that are 100% efficient right now. Could that happen in the future? As more demand for clean energy occurs, you can expect new products to be developed that better meet the needs of homes, lower upfront costs, and help convert sunlight faster.

Why are solar panels not very efficient?

There are various reasons why this occurs. For example, solar panel efficiency is limited because some of the photons that hit the surface of the solar panel are reflected away from it. Not all of the solar radiation that hits the panel is absorbed. And, some of what does hit the panel will turn into heat during the process and do not lead to the production of electrical current.

Meet the author:

Joey Cheek

Joey Cheek spent 10 years on the US National Speedskating Team where he competed in two Olympic Games, winning gold, silver, and bronze medals. He attended Princeton before diving into the startup and tech world. In 2011 he launched a livestreaming platform for sports before leading a team of engineers building next-gen news and content apps for Fortune 100 companies. He is the CEO and co-founder of SmartSolar.org, whose mission is to move the earth to cheap, abundant, carbon-free energy.

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