Heterojunction know-how (HJT) is a not-so-new photo voltaic panel manufacturing methodology that has actually picked up steam within the final decade. The know-how is presently the photo voltaic business’s most suitable choice to extend effectivity and energy output to their highest ranges. HJT combines one of the best qualities of crystalline silicon with these from amorphous silicon thin-film to supply a high-power hybrid cell that surpasses the efficiency of the business’s go-to know-how, PERC.

REC’s Alpha Sequence 60-cell module with HJT

HJT’s newest headline seize got here in Might when REC Group announced the business’s strongest 60-cell photo voltaic panel at 380 W, a feat made attainable by HJT processes perfected by gear producer Meyer Burger, an HJT market chief since 2010. As the one gear provider providing a turnkey HJT manufacturing course of, Meyer Burger is establishing a motion — the corporate supplied equipment to EkoRE’s under-construction 1-GW HJT line in Turkey in addition to SolarTech Common’s line of HJT panels produced in Florida, and an unnamed North American photo voltaic cell startup plans to use Meyer Burger’s HJT know-how because it ramps up.

Different giant Asian names are going all-in on HJT on their very own. Jinergy was one of many first corporations to commercialize HJT modules in China and announced in March 2019 that it has reached 23.79% effectivity on its HJT cells, and its 72-cell JNHM72 module reached 452.5 W. Risen Power broke ground on a 2.5-GW HJT cell and module manufacturing plant in China in August 2019 that must be accomplished in 2021.

The 2019 “Worldwide Expertise Roadmap for Photovoltaic” report expects HJT cells to realize a market share of 12% in 2026 and 15% by 2029 — a gentle rise for a know-how that only a decade in the past was solely utilized by Panasonic.

The grey parts of the bars present heterojunction know-how’s share of the market. Supply: 2019 Worldwide Expertise Roadmap for Photovoltaic

The HJT manufacturing idea was developed by SANYO Electrical within the 1980s (SANYO was acquired by Panasonic in 2009). SANYO was the primary firm to commercially produce photo voltaic cells made from amorphous silicon (a-Si). This thin-film technology, mostly present in pocket calculators, absorbs a variety of the sunshine spectrum however has a low conversion effectivity (the very best effectivity on report for a-Si is 13.6%). So, SANYO performed with a-Si cells, ultimately laminating them with crystalline silicon wafers and a clear conducting oxide (TCO) layer. The c-Si part introduced elevated effectivity stability whereas the a-Si facet included the elevated gentle absorption. Heterojunction know-how was born.

SANYO marketed its HJT modules below the model title HIT (Heterojunction with Intrinsic Skinny-layer know-how), which Panasonic nonetheless makes use of immediately. The first HIT modules, launched in 1997, had been 14.4% environment friendly and produced 170 W. Panasonic’s latest 60-cell HIT models common round 20% environment friendly and produce over 330 W.

Meyer Burger and different photo voltaic gear distributors jumped on the HJT bandwagon after SANYO/Panasonic’s patents on the HIT know-how expired in 2010. Dan Glaser, an engineer at Panasonic Life Options of America, mentioned Panasonic embraces the business’s help of its unique know-how.

Panasonic’s HIT+ N340 collection of module with HJT

“Rising the manufacturing capability and R&D assets for heterojunction know-how shall be wonderful for all downstream prospects. It would solely assist to decrease prices, enhance effectivity and enhance reliability,” Glaser mentioned. “We welcome and encourage others to embrace heterojunction know-how due to its potential to create a greater life for particular person prospects in addition to a greater world.”

Meyer Burger has emerged as a pacesetter in HJT due to its repeatedly examined manufacturing course of. Its HJT fabrication gear makes use of decrease temperatures and fewer vitality than conventional manufacturing strains — an necessary qualification for excellent HJT end-products. The delicacy lies with the TCO layer that primarily bonds the a-Si and c-Si wafers collectively. The TCO deposition should not be too sizzling to have an effect on the delicate a-Si layer.

Count on extra corporations to leap on the HJT bandwagon as they weigh the choice to replace present PERC strains or go in a very totally different path. The HJT manufacturing course of makes use of four fewer steps than conventional PERC, so there may be room for vital value financial savings after preliminary startup. And the potential energy and effectivity positive aspects are even better.

Panasonic’s Glaser mentioned the corporate is sticking with heterojunction know-how as a result of it usually results in a decrease levelized value of electrical energy — which means increased buyer satisfaction.

“One of many benefits of HIT is its low temperature coefficient. By having a decrease temperature coefficient than different modules, we discover that HIT can produce extra vitality over the lifetime of the system than a module of comparable nameplate wattage,” he mentioned. “This in the end can save a client hundreds of {dollars} over the lifetime of the system.”


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