2018 was another big year for photovoltaics, with Australia installations tripling and the global market also growing, despite initial fears arising from a cutback in China. Manufacturing of the UNSW invented and developed PERC cell (Passivated Emitter and Rear Cell) also grew more quickly that expected, with the PERC cell now dominating worldwide production, accounting for over $15 billion in PERC module sales in 2018.
Average module wholesale selling price also decreased rapidly, from US$0.331/watt in 2017 to to US$0.269/watt averaged over 2018, a 20% decrease, further decreasing another 20% to $US0.219/watt for January 2019 (PVinsights data for multicrystalline modules). Such price decreases are expected to drive module production to the terawatt/year level over the coming decade. 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 2K.
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. This accounts for the rapid uptake of the PERC cell. At UNSW, we are now working towards tandem cell stacks that have the potential to eventually double module efficiency from values now approaching 20% for PERC modules to values close to 40%.