The efficiency of a solar module deals with the ability of a PV panel to convert the incident solar light into electrical energy per unit area. With many advancements taking place at both cell and module level, the average efficiency of a solar panel has been continuously increasing. According to the International Technology Roadmap for Photovoltaic 2018 (ITRPV), the average module efficiency in 2017 was 17.7%, a 0.2% absolute jump over 2016's level of 17.5%, both referring to a 1.6 m2 module area.
When it comes to the best crystalline module efficiency, Kaneka holds the world record of 24.4% for a solar panel built with heterojunction back contact cells. Such record module efficiency shows the potential for the respective technologies, but usually commercial production values are somewhat lower.
According to TaiyangNews' research (status: July 2018), the highest commercial module efficiency for a 60- cell panel was a standard product from SunPower, which comes with back contact mono cells and reaches 22.7%, 1.2 percentage points higher than in our 2017 report. The other two of the top 3 – LG with 21.1% and Jolywood with 20.9% – are also based on back contact solar cells (see graph). Most of the other high module efficiencies in the graph are based on advanced module technologies, such as shingling, half cells or MBB.
However, today it is still possible to reach high module efficiencies for standard products solely by using high-efficiency front-contact cells. Panasonic, for example, offers a 19.7% module, while the same module efficiency was reached by NSP's standard PERC module.
The text is an excerpt from the TaiyangNews Advanced Module Technology Report 2018, which was released at Renewable Energy India Expo 2018 and can be downloaded for free here.
Correction: The text was changed and graph updated as SunPower had first provided old data for their record commercial module, which actually comes with an efficiency of 22.7% (and not 21.5% as reported earlier)