Last year (2017) was a big year for photovoltaics, with shipments exceeding 100 GW (0.1TW) for the first time and the year forming the 20th in an unprecedented growth cycle where shipments have increased at a compounded rate of 40% each year, increasing by 1,000 times over this period. If this growth can be sustained for another 7 years, annual shipments would then exceed 1TW.
This terawatt level is particularly significant since, if displacing coal from electricity production or oil from transport, it would reduce global CO2 emissions by the figure of approximately 1.4Gt/year needed by then to maintain an emissions trajectory limiting global temperature rise to 2oC. Continually decreasing photovoltaic system costs will be key to sustaining this growth.
Cell efficiency is becoming increasing important in contributing to such cost reduction as the area dependent costs of encapsulation, transport and installation become increasingly important. The UNSW high efficiency Passivated Emitter and Rear Cell (PERC) now accounts for a third of global manufacturing capacity with 42.38 GW PERC capacity reported by EnergyTrend at the end of 2017, with PERC expected to account for most well before 2020. At UNSW, we are now working towards tandem cell stacks that have the potential to eventually double module efficiency to values close to 40%.