(Nanowerk Information) Photo voltaic power is nice information for planet Earth – however photo voltaic panels will not be as climate-friendly as they need to be. Researcher Martin Bellmann makes use of what he calls ‘black gold’ waste supplies from photo voltaic panel manufacturing to make new panels.
Photo voltaic power is clear power. Pure and easy. However issues begin to get sophisticated with regards to getting the uncooked supplies we have to make photo voltaic panels. Not solely do many of the uncooked supplies come from China, however as a lot as a 3rd of the fabric is misplaced within the manufacturing course of.
“However it’s attainable to recuperate this materials as a part of the manufacturing course of”, says Martin Bellmann. “And perhaps it’s going to allow us to construct a brand new solar-based business in Europe”, he stated. Bellmann is a Senior Enterprise Developer at SINTEF Business and heads the EU-funded worldwide photo voltaic panel mission referred to as Icarus. Photo voltaic panels at present symbolize 60 p.c of the worldwide progress in renewable power.
From quartz to crystalline silicon
Bellmann explains how photo voltaic panels begin with the mineral quartz, which is used to make super-pure silicon. First, the silicon is melted in a crucible and a silicon crystal, or ingot, is eliminated.
“The ingot types a sort of cylinder that grows and expands by slowly pulling the silicon out of the crucible” says Bellmann. “Then it’s reduce to kind a square-sided block that’s sawn into skinny slices, or thins, as we researchers name it”, he stated.
A typical wafer is just 0.13 millimeters (13 micrometres) thick, and these wafers are used to make photo voltaic panels.
However all this sawing leads to lots of ‘sawdust’ powder. It is like sawing wooden – some wooden is misplaced within the type of sawdust. The identical factor occurs while you see by way of a silicon ingot, even in case you use a skinny diamond wire. Some materials usually disappears as ‘silicon powder’.
Photo voltaic panels at present symbolize 60 p.c of the worldwide progress in renewable power.
Mowing wastes 35 p.c
“We misplaced 35 p.c of the silicon within the type of a black powder,” Bellmann stated.
This powder, which he referred to as the brand new black gold, geared toward researchers to use.
“Now, we’re simply throwing this powder away,” Bellmann stated. What the Icarus mission is doing, firstly, is methods to return the powder to the worth chain and use it to make silicon crystals and photo voltaic panels”, he stated.
The powder is collected in a liquid sludge combination that additionally comprises contaminants from the sawing course of corresponding to oxygen, carbon, nickel, iron and aluminum.
“Silicon contaminated with these metals just isn’t good for making photo voltaic panels”, insists Bellman
That is why he’s working with colleagues within the Icarus mission to search out methods to decontaminate silicon powder in order that it may be recycled as a uncooked materials for brand spanking new photo voltaic panels. What we now take into account waste can be utilized for different merchandise corresponding to electrical automobile batteries. Many colleagues have tried alternative ways to separate the silicon from the contaminated combination.
A few third of the fabric is misplaced within the manufacturing course of.
A Europe-wide mission
Naturally, the objective is to make higher use of the uncooked materials, which in flip might be good for the setting and the local weather. However additionally it is a acknowledged objective that Europe should obtain larger self-sufficiency.
“The photo voltaic panel sector in Europe was larger than it’s now, however every little thing has moved to China”, says Bellmann. “In the present day, we’re very depending on uncooked supplies from Asia, and silicon isn’t any exception. We plan to make use of silicon powder to assist cut back our dependence on China”, he stated.
Bellmann hopes that the Icarus analysis mission would be the foundation for a brand new business, maybe additionally in Norway. Norwegian power is clear, and it is a large benefit on this context.
Silicon recycling – and extra
A bonus results of the Icarus mission is that the researchers plan to recycle the quartz crucibles used to soften the silicon earlier than pulling it into crystals.
“The crucibles are damaged after they cool within the smelting oven”, stated Bellmann. “Each time you odor quartz it’s a must to get a brand new crucible and throw away the outdated one. Our objective is to make use of it as a uncooked materials for the manufacturing of silicon carbide”, he stated.
Silicon carbide is used within the electronics business, amongst others, and electrical automobiles are simply one in all many merchandise that include the fabric.
“Usually, we use so-called high-purity quartz to make silicon carbide, however it is vitally costly”, stated Bellmann. “Our thought is that it’s attainable to exchange high-purity quartz with crucible waste, which is actually quartz of very excessive purity”, he stated.
The Icarus mission additionally seems to be at recycling graphite waste as a uncooked materials for use in batteries, amongst others.
“Excessive-purity graphite can also be discarded”, says Bellmann. “It’s utilized in furnaces the place silicon crystals are eliminated however should be changed infrequently as a result of it loses its properties. The Icarus mission is at present working with graphite waste, with the intention of recycling this”, he stated.
Info concerning the Icarus mission
The EU-funded Icarus mission is devoted to exploiting as uncooked materials the waste generated within the manufacturing of photo voltaic panels. SINTEF coordinates the mission.
Companions embody Norwegian firms Northern Silicon, Norsun, Resitec and Fiven; Rosi, Grenoble INP, CEA and Benkei from France; Luxchemtech, Bifa and SGL Carbon from Germany; Cidetec from Spain, College of Cyprus, Magneti Marelli from Italy, Gränges from Sweden and Chemconserve from the Netherlands.
