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For those looking for the most efficient solar panels for their solar energy system, the first thing you need to know is how to compare efficiency metrics for different manufacturer brands. Solar panel efficiency is one useful metric used to determine how much power a solar panel produces compared to other products.
Key takeaways about solar panel efficiency
- The most efficient solar panels available today are approximately 23%
- SunPower, LG, and REC Solar make the most efficient solar panels
- Start comparing solar quotes with high-efficiency equipment on the EnergySage Marketplace
Solar panel efficiency: what you need to know
Simply put, solar panel efficiency (expressed as a percentage) quantifies a solar panel’s ability to convert sunlight into electricity. Given the same amount of sunlight shining for the same duration of time on two solar panels with different efficiency ratings, the more efficient panel will produce more electricity than the less efficient panel. Solar panel efficiency is determined by the production of electricity by solar cells, which are in turn influenced by their composition, electrical configuration, surrounding components, and more.
In practical terms, for two solar panels of the same physical size, if one has a 21% efficiency rating and the other has a 14% efficiency rating, the 21% efficient panel will produce 50% more kilowatt-hours (kWh) of electricity under the same conditions as the 14% efficient panel. Thus, maximizing energy use and bill savings is heavily reliant on having top-tier solar panel efficiency.
Many consumers and people in the solar industry consider solar panel efficiency to be the most important criterion when assessing a solar panel’s quality. While it is an important criterion, it’s not the only one to consider while you evaluate whether to install a particular solar panel. Solar panel efficiency relates to the ability of the panel to convert energy at a low cost and high supply rate.
How efficient are solar panels?
Most solar panels are between 15% and 20% efficient, with outliers on either side of the range. High-quality solar panels can exceed 22% efficiency in some cases (and almost reach 23%!), but the majority of photovoltaic panels available are not above 20% efficiency.
Most efficient solar panels: the top 5
Here are the top five best solar panel manufacturers in 2019 ranked based on the highest efficiency solar panel they have to offer:
The most efficient solar panels on the market today have efficiency ratings as high as 22.8%, whereas the majority of panels range from 15% to 17% efficiency rating. SunPower panels are known for being the most efficient solar panel brand available on the market. Though they will come with a higher price tag, SunPower will often be the consumer favorite for anyone concerned with efficiency as a primal metric of interest. However, check out Exhibit 1 to learn about all the top brands and the most efficient solar panels you can get your hands on.
Maximum Production or Maximum Offset: If your goal is to maximize the amount of electricity your system produces or want to ensure you buy the least amount of electricity from the utility, but the amount of roof space you have available to install solar panels is limited in size, you may choose to install higher efficiency solar panels. This will ensure you get the maximum production from your solar panel system.
Cost vs. Value: More efficient solar panels tend to cost more than their less efficient counterparts. You may want to analyze whether that upfront cost difference is justified by the increased saving achieved by generating more electricity over the lifespan of your solar energy system. Increased electricity production means you have to buy less power from your utility and in some states, may also generate higher SREC income. The EnergySage Solar Marketplace makes it easy for you to easily compare your savings from solar panels that vary in their efficiency ratings and if their premium price is justified.
What determines solar panel efficiency?
There are several factors that determine how efficient a solar panel is. At its core, solar panel efficiency is determined by how much incoming sunlight the solar panel can convert into usable electricity. But what factors into that end conversion rate? There are several items that solar cell researchers and manufacturers consider when designing and producing efficient solar panels:
- Material – the type of material (monocrystalline silicon, polycrystalline silicon, cadmium telluride, etc.) impacts how light converts to electricity
- Wiring and busing – the organization of wires and “busbars” on a solar panel that actually capture and transfer electricity impacts efficiency
- Reflection – if light is reflected away from a solar panel, it’s efficiency may be lowered. This is why the glass layer on top of silicon solar cells is so important.
Additionally, factors like being able to absorb light on both sides of a cell (bifacial solar panels) and being able to absorb variable wavelengths of light (multijunction solar panels) change the efficiency equation for solar panels. All in all, there are a multitude of levers that scientists and researchers can pull when working on improving solar panel efficiency. In the end, it’s all about converting more incoming sunlight into electricity.
How efficient are solar panels? Efficiency comparison tables
The two tables below present different views of the solar panel efficiency characteristics of the leading manufacturers who sell solar panels in the United States. Most panel manufacturers produce several solar panel models which range in efficiency ratings. The leading brands in this category will be those that utilize high-efficiency solar cells such as LG and SunPower (who have battled back and forth for the world solar efficiency record) who are widely considered to be the top panel brand on the market for solar efficiency. However, it’s important to understand the difference between setting a maximum efficiency record and maintaining strong and consistent average solar energy efficiency ratings. Therefore, the following efficiency table breaks down the best ways to compare different solar panel options by module efficiency metrics.
Solar panel efficiency rating of PV models by manufacturer
|Solar Panel Manufacturer||Minimum Efficiency (%)||Maximum Efficiency (%)||Average Efficiency (%)|
|BenQ Solar (AUO)||15.50%||18.30%||17.19%|
|Hanwha Q CELLS||17.10%||19.60%||18.31%|
|Mission Solar Energy||18.05%||18.95%||18.55%|
|Neo Solar Power||16.00%||17.00%||16.48%|
|Trina Solar Energy||16.20%||18.60%||17.42%|
To learn more about solar panel efficiency as well as other criteria to evaluate solar panels, see the EnergySage research titled, “How to Evaluate Solar Panels“. If you’re wondering why you even need to care about solar panel efficiency, check out our video below:
Three Tips for Solar Shoppers
1. Homeowners who get multiple quotes save 10% or more
As with any big-ticket purchase, shopping for a solar panel installation takes a lot of research and consideration, including a thorough review of the companies in your area. A recent report by the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) recommended that consumers compare as many solar options as possible to avoid paying inflated prices offered by the large installers in the solar industry.
To find the smaller contractors that typically offer lower prices, you’ll need to use an installer network like EnergySage. You can receive free quotes from vetted installers local to you when you register your property on our Solar Marketplace – homeowners who get 3 or more quotes can expect to save $5,000 to $10,000 on their solar panel installation.
2. The biggest installers typically don’t offer the best price
The bigger isn’t always better mantra is one of the main reasons we strongly encourage homeowners to consider all of their solar options, not just the brands large enough to pay for the most advertising. A recent report by the U.S. government found that large installers are $2,000 to $5,000 more expensive than small solar companies. If you have offers from some of the big installers in solar, make sure you compare those bids with quotes from local installers to ensure you don’t overpay for solar.
3. Comparing all your equipment options is just as important
National-scale installers don’t just offer higher prices – they also tend to have fewer solar equipment options, which can have a significant impact on your system’s electricity production. By collecting a diverse array of solar bids, you can compare costs and savings based on the different equipment packages available to you.
There are multiple variables to consider when seeking out the best solar panels on the market. While certain panels will have higher efficiency ratings than others, investing in top-of-the-line solar equipment doesn’t always result in higher savings. The only way to find the “sweet spot” for your property is to evaluate quotes with varying equipment and financing offers.
For any homeowner in the early stage of shopping for solar that would just like a ballpark estimate for an installation, try our Solar Calculator that offers upfront cost and long-term savings estimates based on your location and roof type. For those looking to get quotes from local contractors today, check out our quote comparison platform.
NOTE: the data in this piece was last updated July 2019 and is updated every 6 months.