Choosing high-efficiency solar panels could save you $3,600—here's how

Solar technology is constantly improving—the efficiency of the average solar panel on the EnergySage Marketplace has increased by about 10% in the last five years alone. 

Most solar panels are at least 20% efficient, but the best ones are over 22% efficient. We reviewed the efficiency ratings of hundreds of home solar panel models and found that five brands stood out: Maxeon, Qcells, Canadian Solar, REC, and Panasonic. 

Highly efficient solar panels can generate greater electric bill savings than their less efficient counterparts, but they cost more upfront. We'll help you decide if the highest-efficiency solar panels are worth it for you and offer some advice on how to keep your panels producing electricity as efficiently as possible.

A solar panel's efficiency measures its ability to convert sunlight into usable electricity. If the sun shines on a solar panel with a 20% efficiency rating, 20% of the sun's energy will convert to solar energy in ideal conditions. Given the same amount of sunlight shining simultaneously on two equal-sized solar panels with different efficiency ratings, the more efficient panel will produce more power than the less efficient panel.

Solar panels comprise multiple silicon solar cells, which determine their overall efficiency rating. The structure and type of silicon crystal (generally monocrystalline or polycrystalline), electrical configuration, and surrounding components of the solar cells all influence that number. 

Higher-efficiency panels are typically more expensive, but depending on your energy needs and the configuration of your roof, they can be worth it.

1. Maxeon 440 W

Maxeon Solar Technologies

Maxeon isn’t just our most efficient panel; it’s our top panel overall. It comes with the highest price tag but can be worth it if your roof has limited space or a lot of shading. Otherwise, you may be better off choosing one of the other highly efficient but more affordable solar panels on our list.

2. Qcells Q.TRON BLK M-G2+ 440 W

Qcells

Our second most efficient solar panel goes to Qcells. While 0.3% less efficient than Maxeon, Qcells gives you a great bang for your buck as the second most affordable brand on our list. But it also places last for temperature coefficient—which means its efficiency drops the most at temperatures above 77°F—so if you live in a warmer climate, it might not be your best option.

3. Canadian Solar TOPHiKu6 455 W

Canadian Solar

Canadian Solar ranks in the middle of the pack of our most efficient panels. At 22.3% efficiency, it has a slight edge over REC and Panasonic. Additionally, it places higher than Qcells overall on EnergySage’s Equipment Rating System. But it’s pricier, so consider another option if budget is a concern.

4. REC Alpha Pure 410 W

GRID Solar and Electric via REC Group 

REC may be tied for the fourth most efficient solar panel, but it ranks second best overall on EnergySage. In addition to its 22.2% efficiency, REC boasts one of the lowest temperature coefficients on the market and has the most affordable price per watt. While it’s a longtime EnergySage favorite, it won’t output quite as much power per square foot as the options above.

5. Panasonic Evervolt 430 W

Panasonic

The Panasonic Evervolt rounds out our most efficient panels. It’s tied with REC as the least efficient panel on our top-five list but takes first place in temperature coefficient. The Evervolt is an excellent option for those in warmer climates, but if you’re not concerned about hot temperatures affecting your system’s performance, you can find a more efficient panel elsewhere.

Choosing efficient solar panels is important, but you don't always need to opt for the most efficient model. Here are some scenarios when selecting the most efficient panels makes sense:

You want to maximize your solar production

Let’s say you want your system to produce as much electricity as possible. Or, maybe you want to buy the least amount of electricity from your utility but have limited roof space. In either of these cases, you should choose the highest-efficiency solar panel.

You want to save more money long-term

Highly efficient solar panels tend to cost more than their less efficient counterparts. But, the higher your panel's efficiency, the more electricity you'll produce, and the more you'll save on your electric bills. 

To understand the cost-effectiveness of each panel option, calculate whether the increased savings you achieve by generating more electricity over the lifespan of your solar energy system with high-efficiency panels justifies the higher upfront cost.

Let's consider two solar panel systems located in Massachusetts. Both have 20 solar panels of the same physical size. One system has Maxeon’s 440-watt panels with 22.8% efficiency, while the other includes panels with 21% efficiency.

Solar savings with high-efficiency panels

*Based on EnergySage Marketplace data.

In the example above, after considering your upfront costs and 25-year electric bill savings, the Maxeon system would save you $3,658 more overall.

We've gone over the basics of monocrystalline versus polycrystalline panels and the impact each material design has on efficiency, but there's more than just the structure of your panel that determines how well they can turn sunlight into electricity.