Technology

Big size Is the Big Trend

Shravan Chunduri

With the aim to inform the PV community about current and future technology trends, the International Technology Roadmap for Photovoltaic (ITRPV) came out with its latest 12th edition summarizing the results of its research for 2020. The roadmap's basic layout remained the same covering three important aspects of each station of the value chain – material, process and products – however, the latest version adapted few changes following the market dynamics more closely. One important change is module prices determination is adapted to current maker conditions. In the past, only multicrystalline was considered; but now reflecting to the ground reality different products are considered. At the same time, the roadmap has eliminated outdated parameters, for example, related to multicrystalline. Inline to the current trends, the 12th edition of the roadmap has discussed the various parameters related to wafer size / module formats in detail.  This year's results are summarized with the help of 56 international experts along the PV value chain, the edition summarizes and discusses over 100 parameters in several diagrams.
According to the latest edition, PV modules worth of 135 GW were installed worldwide in 2020 with which the cumulative PV capacity significantly exceeds 700 GW. The annual shipments increased despite most of the year suffered from COVID-19 situation. The global production capacity at the end of 2020 was estimated to have reached 270 GW, double the shipment and 93% of this account to crystalline silicon.
For several decades, the analogous trend to the general concept of an experience curve has been observed. This shows that each doubling of cumulative PV module capacity installation is associated with a price reduction of 23.8%. However, an accelerated learning of 40.2% was observed between 2006 and 2020. Based on recent results, the trend is expected to continue along this experience curve over the next several years, even though module prices went up in recent months due to high demand, and component and material shortages.
The long term reduction trend will be realized through a combination of several measures: improved and larger silicon wafers, implementation of cell perfections, optimized cell fronts and backs, refined layouts, the introduction of bifacial cell concepts, and optimized cell and module technologies. It is quite evident that PERC is today's workhorse of the PV industry and the roadmap found that new formats are attracting some price premium.
As for the wafer type, the roadmap is very optimistic about the wider adaptation of the market towards monocrystalline silicon, which has reached a 80% share already in 2021. It also anticipates that the share of higher-quality n-type material will increase from the current 10% to about 50% in 10 years.  In the area of new formats, a strong trend is observed towards larger wafers. The roadmap forecast that yesterday's standards such as 156.75 mm (M2) and 158.75 mm (G1) will disappear in favor of larger formats within the next 4 years. Currently, the main wafer size is 166 mm (M6), 182 mm (M10) and 210 mm (M12/G12). The market share of the current mainstream format M6 is expected to drop from 34% in 2021 to 5% in 2031, while M10 and M12 will lead with 42% each.
At cell level, PERC cell technology was the dominant technology in 2020 with a market share of 8 % and this cell architecture is expected to retain its dominance with a share of 70% down the line over the next 10 years; during this time, HJT is expected to achieve a 17% market share, while other high efficiency technologies, such as integrated back-contact (IBC) and tandem approaches are expected to gain 5% share each.
The implication of larger wafer formats is mainly felt at the module level, resulting in larger modules both in rooftop and in power plant applications. In rooftop applications, modules smaller than 1.8 m² have a market share of 83%. The limitation in terms of module area can be attributed, among other things, to manual installation. In power plant applications, 25% of modules are currently larger than 2.2 m², with this share expected to increase to over 90% in 2031. The 12the edition anticipates that very large modules with areas exceeding 3 m² will have a 16% share. These larger modules based on larger wafer formats are often combined with half-cell layout; products with rated power exceeding 600 W have started hitting the market.
At the product level, with the advent of high-quality n-type wafers and gallium doping of p-type material, the product warranty is expected to increase to 15 years and performance warranty is to increase to 30 years across the board. Even the spec for first year degradation is expected to come down from the current level 2% to 1%.
The new ITRPV roadmap is for download here.