couple standing front of their house with solar panels

As solar energy technology progresses at a rapid pace, there’s never been a better time to take advantage of the significant gains in production efficiency. And the future is even brighter, with promising technologies on the horizon. Here’s what you need to know about solar panel efficiency in 2018.

The Importance of Solar Panel Efficiency

Solar panel efficiency determines how much energy is produced from a certain amount of sunlight and is a function of the materials used and the production technology. The greater the efficiency, the more solar electricity the solar panels produce within a given space. Because solar panel efficiency has never been higher, solar shoppers have more high-efficiency panels to choose from.

Efficiency is most critical where space for panels is limited. If a homeowner wants to generate all their own power, then space constraints can be a real issue. For example, a solar panel that is 18 percent efficient will generate 50 percent more electricity than a panel that is 12 percent efficient.

The Price Premium for Solar Panel Efficiency

SunPower, Panasonic and LG currently manufacture the most energy-efficient solar panels available on the market, with an average efficiency rating of 22.2 percent, 20.3 percent and 20.1 percent, respectively. These manufacturers also offer a 25-year warranty.

By comparison, most solar panels are between 15 and 18 percent efficient. Although this might not sound like much, exploring historical solar information tells a different story. The first solar cells created in the 1800s were less than 1 percent efficient. In the 1950s, Bell Labs produced a solar panel that was 6 percent efficient. There are now solar panels used in space applications that are 40 percent efficient, but these panels contain very expensive materials and aren’t financially feasible for residential solar applications.

Keep in mind that although solar panel efficiency is an important consideration when going solar, it is not the only one. The additional cost of high-efficiency solar panels may not be justifiable for many solar projects, especially if there is ample space. If a roof is shaded, other technologies exist, including microinverters and power optimizers, that mitigate the effects of shade on solar system output.

Solar shoppers will find many options to choose from: There are more than 100 solar panel types on the market. In addition to efficiency, other important considerations when selecting a solar panel include solar panel warranties, durability, cost, value and aesthetics.

Learn More About Solar Panel Options

To find the best solar energy system for your home, do some comparison shopping. UnderstandSolar and EnergySage are two free services that link you to top-rated solar installers for solar estimates. Because of the variety of solar panels available on the market, different solar installers will likely use diverse products. It’s helpful to conduct your own research of solar panels to make sure you get the system that best serves your location and budget.

By Sarah Lozanova

Sarah Lozanova is an environmental journalist and copywriter and has worked as a consultant to help large corporations become more sustainable. She is the author of Humane Home: Easy Steps for Sustainable & Green Living, and her renewable energy experience includes residential and commercial solar energy installations. She teaches green business classes to graduate students at Unity College and holds an MBA in sustainable management from the Presidio Graduate School.