New solar panels from photovoltaic panel waste

Nov 29, 2022 10:03 AM ET
  • Solar energy is great information for planet Earth-- but solar panels are not as climate-friendly as they should be. Researcher Martin Bellmann is using what he calls the "black gold" waste materials from solar panel manufacture to make new panels.
New solar panels from photovoltaic panel waste
Image: Thor Nielsen

Solar energy is clean energy. Pure and simple. Yet things start to obtain complicated when it concerns obtaining the raw materials we need to make photovoltaic panels. Not just do most of these basic materials come from China, however as high as a third of the product is shed during the manufacturing process.

" But it's possible to recover this product as part of the manufacturing process," states Martin Bellmann. "And also possibly this will certainly enable us to develop a new solar-based sector in Europe," he claims. Bellmann is a Senior Business Developer at SINTEF Market and is heading the worldwide photovoltaic panel project called Icarus. Solar panels currently stand for 60% of international growth in renewable resource.

From quartz to crystalline silicon

Bellmann describes exactly how photovoltaic panels start with the mineral quartz, which is made use of to make super-pure silicon. Initially, the silicon is melted in a crucible and also a silicon crystal, or ingot, is pulled out.

" The ingot forms a type of cylinder that grows as well as expands by slowly pulling the silicon from the crucible" says Bellmann. "It is then reduced to form a square-sided block which is sawn right into slim pieces, or wafers, as we scientists call them," he states.

A typical wafer is just 0.13 millimeters (13 micrometers) thick, and also it is these wafers that are made use of to make photovoltaic panels.

But all this sawing results in a large amount of "sawdust" powder. It's much like sawing a wood plank-- some of the timber is shed in the form of sawdust. The exact same thing happens when you translucented a silicon ingot, even if you utilize slim diamond wires. Some material will certainly constantly be shed as "silicon powder."

Sawing wastes 35%.

" We lose 35% of the silicon in the form of a black powder," claims Bellmann.

It is this powder, which he calls the new black gold, that the researchers are aiming to make use of.

" Today, we simply throw this powder away," states Bellmann. What the Icarus project is doing, first and foremost, is checking out methods to return the powder to the worth chain and also use it to make silicon crystals and also solar panels," he states.

The powder is accumulated in a liquid sludge mixture that also consists of contaminants from the sawing process such as oxygen, carbon, nickel, iron as well as aluminum.

" Silicon contaminated by these metals is bad for solar panel manufacture," claims Bellman.

This is why he is interacting with Icarus project partners to find methods of sanitizing the silicon powder to ensure that it can be recycled as a raw material for new photovoltaic panels. What today we consider as waste can be used in other products such as electrical vehicle batteries. A variety of partners are evaluating different means of separating silicon from the contaminated mixture.

A Europe-wide project.

Normally, the goal is to much better manipulate the raw product, which in turn will benefit the environment and the climate. Yet it is also a stated goal that Europe ought to achieve greater self-sufficiency.

" The European solar panel industry was once bigger than it is now, but every little thing has actually been moved to China," states Bellmann. "Today, we're heavily reliant on resources from Asia, as well as silicon is no exception. We're planning to make use of the silicon powder to help reduce our reliance on China," he claims.

Bellmann is wishing that the Icarus research project will certainly form the basis for a new sector, perhaps likewise in Norway. Norwegian energy is clean, and also this is a major advantage in this context.

Recycling silicon, as well as much more.

A bonus resulting from the Icarus project is that scientists are planning to recycle the quartz crucibles that are made use of to smelt the silicon prior to it is pulled right into crystals.

" The crucibles fracture when they cool down in the smelting stove," claims Bellmann. "Every single time you smelt some quartz you need to get a new crucible and also throw the old one away. Our objective is to use this as a basic material for making silicon carbide," he claims.

Silicon carbide is utilized in the electronic devices market, to name a few, and electric vehicles are just among many items which contain the material.

" Normally, we make use of so-called high-purity quartz to make silicon carbide, but this is extremely pricey," says Bellmann. "Our idea is that it could be possible to change high-purity quartz with crucible waste, which is also fundamentally quartz of extremely high purity," he states.

The Icarus project is likewise looking into recycling graphite waste as a resources for use in batteries, among others.

" High-purity graphite is also discarded," claims Bellmann. "It is utilized in the stoves where the silicon crystals are pulled out but needs to be replaced every now and then since it sheds its homes. The Icarus project is currently collaborating with graphite waste, with the goal of recycling it," he says.

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