The solar panel industry in Australia must embrace circular economy approaches and stop sending panels to landfill, an engineering conference in Melbourne has heard.

Speaking at the Climate Smart Engineering Conference hosted by Engineers Australia in November, Kavya Santhosh, Solar Asset Manager at photovoltaic power plants technical services provider ENcome Energy Performance, said that the solar PV industry needs to reduce the number of panels which end up in landfill.

According to Santhosh, the industry remains stuck in a ‘linear’ mode of operation.

This adopts a ‘take/make/waste’ approach which sees panels sent to landfill at the end of their useful life.

“This is literally what is happening with PV panels,” Santhosh says, showing a picture of a solar panel stacked on top of a pile of garbage at a rubbish tip.

“As discussed in all these sessions (earlier in the conference), we always talk about moving from the linear to the circular economy.

“At the moment, we (the solar industry) are in the linear phase of it.”

The presentation comes amid growing concern about the level of waste which is being generated as a result of discarded solar panels.

All up, solar power accounted for 14 percent of the Australia’s electricity generation in 2022, according to the Department of Climate Change, Energy, the Environment and Water.

With the nation aiming to increase renewable energy penetration from 34 percent of overall energy generation in 2022 to 82 percent by 2030, investment in new solar farms is ramping up.

With this comes concern about the volume of solar PV waste that is likely to end up in landfill.

According to Santhosh, current projections show that between 1.7 and 1.8 million tonnes of solar PV waste will be lying in landfill around Australia by 2030.

By 2050, this number is likely to increase to between 60 and 80 million tonnes.

Sending panels to waste can lead to soil and groundwater contamination. This is especially problematic where leeching of toxic materials occurs.

(Normally, to prevent leeching, the panels are transported and disposed of in landfill as one piece. However, leeching can occur when panels are damaged or broken either during transport or in disposal. When this occurs, toxic substances can penetrate the soil from broken pieces.)

Whilst there are three broad types of solar PV panels, the most commonly used type is comprised of silicon-based cells which are arranged in thin layers and are sandwiched between two layers of aluminium and glass.

Popular on account of their low cost, efficiency and ease of use, these cells are highly recyclable as their material composition is primarily aluminium, glass, silicon and plastic as well as silver, tin and lead.

For several reasons, however, Santhosh says that the panels commonly wind up in landfill.

First, it is usually cheaper and easier to purchase new panels than to recycle existing ones.

Next, there is a lack of processes which have been suitably developed so as to enable recycling to be done in a cost-effective manner.

Contributing to this is a lack of research and literature on recycling methods. In particular, there is a lack of modelling and analysis regarding the impacts particular recycling methods upon the environment.

As a result, Santhosh says it can be difficult to quantify any costs and benefits which are associated with particular recycling methods in terms of environmental impact.

This leads to difficulty in determining which methods if any offer a solution which is truly sustainable and affordable.

To overcome these challenges, Santosh says three things must happen.

First, governments and stakeholders should develop standardised approaches to the PV manufacturing process along with consistent techniques for manufacturing and assembling panels across industry.

From there, it will be possible to develop standardised processes for disassembly and recycling.

As things stand, solar panel recyclers are being hampered by the need to cater for various types of panels which are manufactured across different countries.

This adds cost and complexity to the recycling process and can drive a need for multiple recycling facilities that each employ different technologies.

Next, it is important to improve the lifespan and durability of the panels themselves.

As things stand, the end-of-life for panels is usually taken to be when the efficiency of the panels drops to below 80 percent.

On average, degradation of the panel causes their efficiency to drop by 0.5 percent annually.

Causes of panel failure can include poor design and manufacturing defects, damage to electrical equipment, light erosion, degradation of the anti-reflective coasting layer of ethylene-vinyl acetate (EVA) on the glass and environmental contributions to degradation as well as contact-related factors such as hailstones.

To extend PC panel lifespan, Santosh says that strategies should include:

• Optimising the novel circuit design to reduce the number of components within the system. This contributes to less maintenance along with improvements in packing efficiency.
• Incorporation of a modular inverter design which allows for easy component replacement and enhances the reliability of the PV system.
• Use of wide-bandgap semiconductor switches which can operate at greater temperatures with a lower likelihood of power failure.

Finally, Santosh says that indicators such as the material circularity index (MCI) and material reutilization score (MRS) should be taken into consideration during the design and manufacture of systems.

Since these standards are not mandatory, Santosh says this further underscores the need for standardised approaches referred to above.

All up, Santosh says the industry needs to move away from landfill.

“At the end of the day, this is what we are looking at,” she said.

“We want to move back to a circular system where you can actually recycle, reuse and refurbish these and get them back into the system.

“That’s when you create a management system for the circular economy.”

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