One of the most efficient solar PV panels of 2011 is undoubtedly that manufactured by REC. The reason I say this is because these panels achieved top place in a field test run by Photon magazine, having consistently occupied a leading place over the last eighteen months.
The Photon field test is conducted in Aachen, Germany, and is the most recognised field performance test in the world. The REC panels consistently outperformed competitor panels generating an average of 6% more power. Part of the reason for this outstanding result is that although REC panels are made with polycrystalline PV, they have an anti-reflective coating which enhances efficiency in a variety of weather conditions and light levels.
Close behind REC is the popular Sanyo HIT series of panels. These are hybrid panels, HIT means ‘Heterojunction with Intrinsic Thin-layer’, the panels are constructed of a single thin crystal layer coated with an amorphous non-crystal silicon layer and this helps to reduce surface energy loss thereby improving performance. The acclaimed N-series are particularly popular because its 240 W module has a 21.6% cell conversion efficiency with an overall module efficiency of 19%. The HD series with its 250W module is also highly esteemed with a 20.8% cell efficiency with 18% for the module.
Another good brand is Sunpower and their E19 series is claimed by the company to have more cells within each conventional-sized panel than rival brands. This gives the panels 21.5% conversion efficiency, only slightly behind that of the Sanyo HIT. The Sunpower E20 panel was recently named as the most efficient mass-produced solar panel by the Guiness Book of Records. Like the REC panels it has an anti-reflective coating which helps to improve efficiency.
Another brand worth watching is GEC who earlier this year announced that it was going to build a 400MW factory to produce what it claims will be the world’s most efficient solar panel which will be a thin-film solar cell incorporating cadmium telluride. The company claims that its products will be more efficient than any other solar technology on the planet.