Solar Energy: Recycling process promises 'better than new' silicon wafers

[Caribbeans]

A new process to recover wafers could dramatically cut the energy cost required to produce recycled silicon cells. Image: Ministère de la Transition écologique

Recycling process promises ‘better than new’ silicon wafers

PV-Magazine.com | June 16, 2022 | Mark Hutchins

As the solar industry comes of age, dealing with the growing volume of products reaching end of life is already a research priority at universities and institutes the world over. Many different approaches are on trial, though experts are waiting until later this decade when the volume of products is expected to grow significantly, giving them room to experiment with processes at large scale.

Processing and purifying silicon from end-of-life cells back to a state where it can again be inserted back into the PV supply chain to make new cells has proven a major challenge here. It requires high levels of energy and a complex understanding of tiny impurities left in the recycled silicon that differ from brand new material.

Some already say that diverting this silicon to applications with lower purity requirements is the best solution. However, a group of scientists led by the Key Laboratory of Urban Pollutant Conversion at the Chinese Academy of Sciences may have come up with an alternative – one that cuts out the energy-intensive ingot production stage entirely.

...With this in mind, the group sought ways to recover silicon wafers suitable for production of high efficiency cells and modules. They demonstrated a series of chemical treatments that are shown to both purify wafers and improve their surface characteristics, making them suitable for use in new, high-efficiency cells. The process is described in full in “A systematically integrated recycling and upgrading technology for waste crystalline silicon photovoltaic module,” which was recently published in Resources, Conservation and Recycling. MORE:
https://www.pv-magazine.com/2022/06/16/recycling-process-promises-better-than-new-silicon-wafers/

RELATED:

World’s largest solar plant goes online in China



PV-Magazine.com | OCTOBER 1, 2020

...Chinese inverter manufacturer Sungrow, which supplied the inverters, said that the 2.2 GW solar plant was built in five phases. It involved an investment of RMB15.04 billion ($2.2 billion) and includes 202.8 MW/MWh of storage capacity. The company announced the storage system as a solar+storage project in mid-May, but at the time it did not reveal that it was to be connected to a giant solar plant...more
https://www.pv-magazine.com/2020/10/01/worlds-largest-solar-plant-goes-online-in-china/

Isn't everyone glad that the US Congress gave tax credits to US Corporations to outsource their manufacturing to China - back when the US made things besides surveillance gear and war toys?

China is.

[Finishline42]

1. Obviously I would rather solar panel mfg was in the US... but

I think the mfg of solar panels is similar to flat screen TV's in that you rarely get the long life of the equipment you need to generate profit. The technology is improving at a rapid pace. Build a plant in 2-3 years, get 3 yrs production from the equipment and now you are out of date with the latest and greatest and struggle to sell enough to cover cost. I think that is what happens with Flat screen TV's.

The money is in the jobs provided to installers and long term savings solar provides.

IMO, there should be a program to build out solar at schools and govt facilities. Especially for schools, they own the land, are open mainly in the daytime, are closed in the summer (would generate excess power to be used by the local community) and generally don't move around. Would be able to take advantage of the long life of the panels (less than 1/2% degradation of output per year). Has me shaking my head on why we tax payers continue to pay utilities (typically monopolies - supposedly regulated but those PSC's are normally filled with utility supporters) the ever increasing amounts every month.

[NNadir]

2. The tragedy of this scheme will involve the chemistry.

In all my years in the lab - I've worked with many extremely dangerous reagents - the scariest moment was when some subordinates caused an HF leak in a hood. Because I could not rely on their competence I cleared the lab, suited up and cleaned it up myself.

Now we are hearing that processing millions of tons of HF for a putative solar industry that has zero success at addressing climate change is admirable and "green."

Ignorance isn't bliss. It's dangerous.