Making solar panels more sustainable

As first generation large-scale solar panels reach and surpass their estimated 25 to 30-year lifespan, many thousands of units will need to be removed and dismantled, with many potentially ending up in landfill. To address this, recycling companies and other cleantech innovators are exploring ways to improve the solar power industry’s circularity

The UK’s solar capacity has been growing rapidly in line with the Government’s clean power initiative, which aims to ensure that at least 95% of the nation’s energy comes from low-carbon sources by 2030. In fact, 2025 was a record year for UK solar power generation, with an estimated 18,314GWh of solar electricity generated, according to the National Energy System Operator (NESO). However, the rapid expansion of solar power generation brings with it a major environmental challenge, with estimates suggesting that 78 million tonnes of solar panel waste could be produced globally by 2050.

Whilst many of the materials used to manufacture mainstream crystalline silicon (C-Si) solar panels are widely used and in high demand, they can be challenging to extract, which makes them difficult to recover and recycle. Glass is the main component of solar panels, representing about 75% of their overall content, but other components include aluminium and plastics. The silicon used to make the active region is a valuable material, but it is typically held in a layered structure, coated with ethylene-vinyl acetate and can therefore be challenging to recover.

Compared to silicon solar panels, thin-film solar panels can be cheaper to manufacture and require less active material. However, thin-film solar panels often use hazardous chemicals such as cadmium telluride. As a result, these solar panels require careful end-of-life management.

Research scientists with an interest in driving the sustainability of the solar power industry have been searching for new alternative materials for use in solar cells, which could eliminate the need for harmful chemicals. For example, research scientists at the University of Bath have been using AI-powered computational methods to identify new materials that offer strong energy conversion performance, with a view to replacing the need for silicon. One promising candidate material is kesterite, which is a mineral made up of copper, tin, zinc/iron and sulphur. An innovative method of obtaining a kesterite thin-film solar cell has been granted recently in the US - (US12154995B2) by Italian manufacturer, Isopan S.p.A.

Another prominent strand of innovation activity is focused on developing tests for used solar modules. A patent granted in the US last year - (US12005485B2) - describes techniques that might be used individually or in combination in order to determine whether a module is unfit for reuse and therefore should be sent for recycling, or whether the module requires refurbishment. The patent claims a method including a step of testing a solar cell module prior to shredding by applying polarised light to the glass sheet. The testing also comprises photoluminescence, which involves exposing the module to light in order to generate an electric response (e.g. current).

Recycling a solar module will typically involve chemical processing techniques. For example, a patent granted recently in Australia - (AU2023229502B2) - describes how an ionic liquid comprising organic acid and organic base can be used to dissolve at least one layer of fluoropolymer from a substrate. The patent specifically refers to a potential application in separating a solar panel into recyclable components. As another example, UK company, Solar Recycling Solutions, claims to offer 99% recycling of silicon solar panels, and has developed innovative processes to purify the recovered silicon to a grade suitable for industrial reuse.

In a rapidly growing industry where there is an urgent need for more recycling infrastructure, cleantech innovators should aim to patent their technologies at an early stage. Depending on their business model, doing so could bring lucrative licensing opportunities and attract investor interest.

Contributed by Chris Hunter, a senior associate at European IP firm, Withers & Rogers. Chris is a patent attorney specialising in the clean energy sector.