More details have emerged regarding the plans for collaboration between Tesla and Panasonic at the SolarCity gigafactory under construction in Upstate New York. Citing SolarCity, Recharge reports that SolarCity has stated that it will be a combination of Silevos Triex and Panasonics Heterojunction Intrinsic Thin Film (HIT) technologies.
Tesla had earlier declined to clarify this matter for pv magazine, and there is no documentation of this on either Teslas or SolarCitys website. However, this is par for the course for SolarCity and Tesla, and at the time of publication pv magazine was awaiting confirmation from SolarCity.
While both Panasonic and Silevo make silicon heterojunction solar PV, they are very different. Silevo was a start-up when it developed its Triex PV cell architecture only seven years ago, and while it began mass production in 2011, such production has remained at a relatively small scale. A year ago SolarCity/Silevo claimed that it had produced a 22.04% efficiency PV module, however the company has declined to provide information on the current efficiencies of mass-produced Silevo PV modules.
Panasonic, on the other hand, is a massive conglomerate that has decades of experience with silicon heterojunction devices, and has produced these modules at a much larger scale than any other manufacturer. The company is currently selling 330-watt, 1.7 square meter PV modules which offer 19.7% efficiency.
SolarCitys Kady Cooper told Recharge that Panasonic will combine the best of the two technologies, however it is unclear how the Japanese PV maker will do that. While both designs incorporate a layer of crystalline silicon PV between two layers of amorphous silicon and while SolarCity notes that the tools used are similar, Silevos design is based on Metal Insulation Semiconductor PV technology, and in the past has emphasized the difference between the two.
Under the agreement, which is still a non-binding letter of intent, Panasonic will operate the factory and sell modules to SolarCity under long-term contracts. Of course, all of this is still dependent upon Teslas acquisition of SolarCity, which will go to a vote of shareholders on November 17.