RECYCLING OF PHOTOVOLTAIC SOLAR PANELS

                RECYCLING OF PHOTOVOLTAIC SOLAR PANELS

What are solar panels?

Photovoltaic solar panels are responsible for generating electricity using the most renewable source of energy that is sunlight. PV modules consist of 6×10 photovoltaic solar cells combined together. Each of the solar cells consists of several compartments as named below:

·        Glasscomprising front of solar panels

·        Aluminium comprising of frame

·        Synthetic material used to seal in the silicon

·        Silicon solar cells

·        Metal

Solar panel consists of large no. Compartments hence it is not easy to regenerate or recycle these solar panels. But the question arises that what is the need to recycle these solar panels? Solar panels can be destroyed by the natural disaster, if interior wires are not installed properly causing a short circuit. PV cells if damaged or stop working the material energy used to manufacture them will not be lost. Approximate age guarantee of PV cells is 25 to 30 years. Eventually after 10 years its efficiency decreases by 10%, after 20 years its efficiency get down by 20%. Thus, PV cycle goes through recycling process to reuse the components.

The PV panel waste on regulatory aspect comes under general waste. But an exception occurs at EU level here these PV panel waste are stated as e-waste in Waste Electrical and Electronic Equipment (WEEE) Directive. Those who manufacture solar cells are bound by certain laws so that they fulfil recycling standards and legal requirements, as to not become a burden on the environment later on. Hence, recycling of solar panels is necessary.

There are two type solar panels i.e. Silicon based and Non Silicon based. Both types of solar panels can be recycled through different approaches.

Silicon based recycling process

All the PV modules are collected and transported to specialised sections toseparate the waste materials. Different kinds of wastes are separated such as plastic, glass, metal etc. Conveyer belts are used to transport these separated wastes to the plant. Further wastes are sorted through hands for better separation.

Through this method 95% of the glass and aluminium parts are separated. Then the remaining parts are gone through thermal processing where silicon and plastic are separated. Silicon wafers are dipped in chemical baths or high tech light sensitive sorting technique, depending on the PV technique used in installation of PV cells. It is further refined till it is safe for new product.

Non Silicon based recycling process

All the PV modules are broken down very harshly. They are hammered till the pieces are not more than 4mm in size. These pieces of PV modules consists both solid and liquid particles. Then it goes through a rotating screw in which all the liquid get dripped to a container and solid particles are kept in the rotating tube of screw.

For ensuring the purity of liquid it goes through precipitation and dewatering process. As soon a new substance is generated it goes to metal processing for proper separation of semiconductors. This technique totally depends on the technique used to install the PV cell. But it results in 95% semiconductor purification.

Solid materials present in the tube are contaminated with inter layers. They are separated through vibration and glass is obtained. Then it goes through rinsing and thus pure glass is obtained, producing 90% glass elements.

Thus, solar panels can be recycled.