Current Technology Trends and Future Advancements in Solar PV

P-type Crystalline Silicon, a technology variant, that has evolved a lot on varied optimised techniques to position solar PV modules in high power and high energy density options in the market. It has successfully emerged as a prominent and accepted PV solution by majority of PV module suppliers. Capability of mass-producing these technology variants with higher power classes and high efficiency determines the long-term viability of these products. P-type Crystalline Silicon has clearly topped the charts as the commercial winner owing to the reduced Levelized Cost of Energy (LCOE) in the last two decades. The technology pretty much paved the path for all the new and upcoming high energy density products penetrating the global solar PV scenario today.

The commercially available P-Type wafers ranging from 158.75 mm to 182 mm or beyond are within the thickness range of 150 to 180 microns and are well diversified within the segment of Mono PERC. This has completely superseded and replaced the 156.75 mm Poly Crystalline P-Type product. All kinds of optimisations in Mono PERC happened within short span of 8 to 10 quarters and is now at the verge of saturation with respect to power and energy density. Global markets constantly foresee reduced tariff trajectories which create the need for new ground-breaking technologies with the metrics of existing P-type Mono PERC as a base case criterion enabling even lower LCOEs.

With the advent of technologies like N-type, PERT, TOPCON, IBC, HJT, etc. that are less prone to induced degradations, the combined benefit will be much better coupled with high efficiency and energy density. At the 2021 SNEC, R&D centres of top-notch PV manufacturers indicated plans specific to these upcoming technologies that may attract big ticket investments. Expected trajectory of technology variants in the existing wafer size can be towards N-type materials like PERT & TOPCON, within the next 12 quarters. This will induce a variety of optimisations in the ‘Bill of Material’ - Cell size, MBB, Spacing between Cells, CTM Efficiency, Multilayer Light Re-directing Films, etc. These advancements shall make the technologies more viable for mass production and give way to commercially competent products (compared to P-type). The market share for Bifacial technologies saw a gradual increase across the globe, especially in ground-mounted projects with GWs of installations. The continued shortfall and rising prices of major raw materials forced most of the developers to shift towards high efficiency and better energy density solutions like Bifacial. Reliability aspects, specific to metrics on Thermal cycle, Damp heat, Humidity Freeze, LeTID and PID instil higher confidence on the longevity of these products to support the 30-year project horizon. LCOE still remains the determining factor for the adoption of Bifacial technology which changed the face of global PV markets.

Tropical Indian climatic conditions with GHIs of 1700-2100 KWh/Sq.mt./Year, require a minimum 300 microns of thickness for backsheet with 3rd generation K film (PVDF) or PVF to withstand these extreme incident irradiances. The reliability factors of these materials can support the 30-year product life. Performance of Bifacial technology varies depending on type of installation, location, and albedo factor and their specific yield is more as compared to Monofacial for a particular location.

Today, we see an increased use of Bifacial variants in standalone PV projects and along with Long Duration Energy storage Technologies within the Distributed Generation segments of some matured markets. The technology is occupying a wider space in the Distributed segment in grid-interactive solutions and in some cases with BIPV + LDES along with Battery bank. Recent tenders with Round the Clock (RTC) demands can be assessed with these latest PV Technologies along with LDES. Thus, operational challenges with intermittent renewables and tropical climates can be mitigated with technology advancements.

- Sai Charan Kuppili, Technical Director,  JinkoSolar