What is solar panel efficiency?

Solar panel efficiency is a measure of how much sunlight that hits the surface area of a solar panel is converted into usable electricity. So, if a solar panel has an efficiency rating of 15%, that means 15% of the sunlight that hits the solar panels will be converted into electricity. The higher the efficiency rating, the more sunlight your solar system can turn into electricity to power your home. 

As solar technology has improved, the average solar cell efficiency rating has continued to increase. At the same time, the cost of solar has continued to decrease. That means you can now get solar that’s cheaper and more efficient than ever! 

Most solar panels sold in 2020 have efficiencies between 15% and 20%, according to the National Renewable Energy Laboratory (NREL). Some solar panels in the market have efficiencies over 20% – these are known as high efficiency solar panels. 

What are the most efficient solar panels in 2020?

Right now, SunPower manufactures the most efficient panels on the market, the Series X, which boast a whopping 22.8% efficiency rating. 

There are a few other solar panel manufacturers that produce premium efficiency panels, which all clock in with efficiencies above 20%. 

The following table lists some of the highest efficiency solar panels on the market:

These solar panels have higher-than-average efficiencies, and also come in at a higher price tag.

So, if you plan to use high efficiency solar panels, keep in mind that your solar panel installation could end up costing you more money than if you used standard efficiency panels. 

Find out how much you can save with solar

What affects solar panel efficiency?

Solar panel efficiency is impacted by many things, but it’s mostly impacted by how the panels are manufactured. Some common factors that affect solar panel efficiency include: 

  • Type of wiring
  • Color of the backing
  • Type of solar cells used

For example, monocrystalline panels will have a higher efficiency than polycrystalline silicon panels because of the way electrons flow through the cells. Most premium efficiency solar cells are made of monocrystalline silicon. 

Learn more: Polycrystalline vs. monocrystalline solar panels

There are other variables that influence your solar panels’ efficiency rating, including their temperature. Higher temperatures will cause the efficiency to drop, whereas colder temperatures will cause the efficiency to increase. 

Additionally, bifacial solar panels, which can absorb light on both the front and the back of the panel, have higher rates of energy production and higher efficiency ratings than traditional solar panels. That’s because solar panels with multi-junction cells are able to absorb different wavelengths of light, bumping up their efficiency. 

However, these types of solar panels aren’t typically used for residential solar installations. 

Learn more: Bifacial solar panels

Is it always better to get high efficiency solar panels?

High efficiency solar panels aren’t necessary for all solar installations. You’ll want to invest in high efficiency solar panels if you have limited roof space and need as few solar panels as possible to produce the most amount of power for your home. 

In most cases, you can get high quality, standard efficiency solar panels and cover all of your electricity needs. Then, you don’t have to worry about paying a premium for the extra efficiency. 

Plus, standard solar panel efficiency is much higher than it used to be, so your panels will still convert a lot of sunlight into solar power for you to use. 

Here are some popular, highly reviewed standard efficiency solar panels:

Advantages of high efficiency solar panels

Despite the good reviews and popularity of standard efficiency panels, there are some clear-cut advantages of high efficiency solar panels – one of which being that they will produce more electricity over the lifetime of the solar system. 

As solar panels get older, their ability to convert sunlight into solar power drops. Since premium efficiency panels already start with a high efficiency rating, as they degrade, they will still have a relatively high efficiency. This means they can produce more energy over time as compared to standard efficiency panels. 

Besides producing more energy over time, high efficiency solar panels have the ability to produce more energy per square foot of roof space. This is because they turn more of the sunlight that hits the roof into solar energy. 

If you have a limited amount of space on your rooftop where solar can be installed, premium efficiency panels may be the best solar panels for your home. 

Final thoughts on solar panel efficiency 

Solar panel efficiency is just one thing to consider when shopping for solar panels. Some other things to consider are the power output rating, the warranty, and the brand of solar panels. 

It’s important to remember that just because a solar panel is the most efficient, doesn’t mean that it’s the best for your home. Your solar installer will be able to help you find the right solar panels to meet your energy needs.

You can also use our solar panel calculator to get a personalized estimate for how much a solar installation would cost for your home.

See which solar panels work best for your specific home