Get what you pay for – pv magazine International

March 23, 2023 George Touloupas

From pv journal 03/23

Advances in PV module know-how have accelerated since 2018. The chart above – based mostly on CEA high quality assurance information – exhibits the most typical modules for utility-scale initiatives in 2017, individually in know-how, has a glass-backsheet construction and has 72 six-inch cells. – a kind of module launched in 2008.

Since 2018, we’ve witnessed the transition from multicrystalline aluminum again floor subject cells to mono PERC (passivated-emitter, rear contact) gadgets; the adoption of half-cut cells; the dominance of bifacial, glass-glass merchandise; the introduction of multi busbar gadgets; a transition to bigger muffins – 166 mm, then 182 mm, then 210 mm; the emergence of gallium doped p-type wafers; and, most not too long ago, the rise of n-type cells – principally n-TOPCon (n-type, tunnel-oxide, passivated contact) merchandise.

Wafer sizes have grown to cut back prices. The market share is at the moment divided between 210 mm and 182 mm wafers as a result of some great benefits of every rely on the venture specs. Because the manufacturing traces might be modified to provide any measurement, the market share is fluid.

Whereas “unique” codecs comparable to 218 mm wafers are unlikely to develop, 182 mm variants are rising, comparable to 182 mm vast 185 mm merchandise designed to reduce the white house between cells in excessive module route. Trina Photo voltaic not too long ago launched a 182 mm vast by 210 mm excessive wafer. In the end, such variants depend on the M10 or G12 photo voltaic ingot platform and provide chains.

N-type actions

N-type (negatively-doped) options have made a formidable entry in 2022 with a number of gigawatts of TOPCon technology capability already being shipped. TOPCon and heterojunction (HJT) cells are the primary high-efficiency contenders to exchange mainstream, p-type PERC cells. The TOPCon and HJT cell structure can be utilized on p-type or n-type wafers however years of analysis have satisfied producers that solely n-type TOPCon and HJT variants can obtain the an optimum value effectivity relationship.

TOPCon is at the moment main the race as a result of legacy PERC cell manufacturing traces might be upgraded to provide them, whereas HJT requires retooling. TOPCon can also be cheaper, because of decrease capital and working prices.

The alternative high-efficiency know-how, interdigitated again contact (IBC) photo voltaic, is acknowledged because the “end-of-the-road” single-junction silicon PV know-how as a result of the larger than 26% conversion effectivity requires tandem cells. IBC cells have their contacts on the again facet, theoretically providing the very best effectivity for single-junction gadgets. Nevertheless, front-contact TOPCon and HJT cells might be transformed to back-contact gadgets and plenty of producers appear to be planning such a improvement. Longi, nevertheless, selected a p-type IBC structure that seemingly makes use of PERC and TOPCon passivation.

The benefits and downsides of competing cell applied sciences are summarized within the following desk, the place IBC refers to any passivation methodology, though properties comparable to bifaciality and tooling capital expenditure (capex) are linked again – contact cells. An intense effort has been made to cut back the silver content material of HJT gadgets.

Benefits and downsides of competing cell applied sciences

Levelized power prices

The tempo of n-type growth will speed up quickly as soon as know-how and value are overcome. Module consumers will settle for a worth premium for n-type if excessive effectivity and improved power yield cut back capex and LCOE.

To measure such financial savings, CEA studied a 100 MW single-axis horizontal tracker system in Spain. PERC and TOPCon cells have been in contrast. Steadiness-of-system element prices are estimated from a number of sources, module value and worth information factors are taken from CEA’s “PV Worth Forecasting Report” and worth monitoring. PVsyst is used to measure power yield.

For the evaluation, CEA outlined a “most worth premium” metric to point out the worth {that a} excessive effectivity module can generate in a PERC panel with out giving up the LCOE benefit.

CEA equates the LCOE for PERC and TOPCon techniques, deriving the TOPCon module worth by including the utmost premium to the PERC module baseline. Calculations present that TOPCon producers can cost a premium of as much as $0.0327/W in PERC with out struggling LCOE. Whereas consumers will not pay the very best premium for the zero LCOE benefit, they are going to pay extra for some LCOE achieve. The next chart exhibits the sensitivity of the LCOE benefit to the premium worth, with premiums under 50% of the very best determine leading to an LCOE benefit of two.5% or greater. On this state of affairs, a premium of lower than $0.016/W could be affordable.

The worth premium for HJT modules – identical effectivity as TOPCon however with greater power yield – might be roughly 30% greater than TOPCon: about $0.005/W. HJT producers ought to work onerous to cut back their value delta at TOPCon and purpose for an excellent lead.

Modules decrease LCOE however pushing previous tipping factors accelerates the speed of change, making it tough to estimate improvement timelines. As an online of things affect LCOE, producer claims require verification.

Concerning the writer: George Touloupas is the senior director for know-how and high quality at photo voltaic and storage advisory Clear Vitality Associates.