The world has witnessed a rapid in­cre­ase in installed solar photovoltaic (PV) capacity over the past few yea­rs. Acc­o­rding to IRENA, in 2020 alone, over 126 GW of solar PV capacity was installed glo­bally. As of now, over 713 GW of solar po­wer has been insta­lled, having multiplied ne­arly 10 times over the past 10 years. In 2011, the capacity stood at 73 GW, and has grown at an average of 70 GW per year.

Solar modules have a life of around 25 years, at the end of which they become un­­profitable. Thus, it is expected that star­ting in 2026, around 70 GW of solar ca­pacity will have to be retired every year. This translates into about 4 million panels per GW or 280 million panels decom­m­issi­oned per ye­ar. Most of these panels will find their way to landfills where they will do more harm than the good done over their lifetime. Moreover, as the dema­nd for solar pa­nels increases with time, raw materials will become increasingly scarce. It is, the­re­fore, an opportune time to understand and establish a circular ec­o­nomy for solar en­ergy to enable an eco­system that en­co­urages repair, reuse and recycling of solar PV materials.

Intellecap attempts to explore the various aspects of the solar circular economy to en­hance the sustainability quotient of solar energy and create an ecosystem to tackle this massive issue that can potentially overwhelm the global solar PV industry.

Defining the ecosystem

By definition, a circular economy is aimed at minimising waste by segregating materials and components derived at the end of a product’s life and reusing them in the manufacturing process of new products, to keep the raw materials circling within the ec­onomy to the maximum extent possible. Extending this definition to the solar industry, a circular solar economy is essentially a process of extracting reusable valuable components and elements from retired so­lar panels and using them to develop new so­lar cells and panels. Productive re­use generates further value out of the product and prevents essential ingredients from ro­tting in the landfills for aeons to come. It also prevents toxic elements used in products from contaminating the environment by making their disposal sustainable.

Driving a circular solar economy

Solar panels use many elements that are precious and finite in nature including silicon, indium, silver, tellurium and copper. These are rare earth elements that are mined and refined to be used in solar panels. Developing countries have large reser­ves of these raw materials. According to the Center for Strategic and International Stu­dies, China produces nearly 90 per cent of the world’s rare earth metals, a large part of which is also used in making solar cells. Neither the mining nor the refining process is sustainable and leads to gross wastage of resources. Therefore, at the end of a so­lar panel’s life, discarding the panels al­to­gether will not only lead to wastage of precious metals and associated was­tage of resources, but also cause environmental poisoning. Developing a circular economy will create a process to feed the recovered material back into the system to avoid wastage at multiple levels.

As the demand for solar energy increases, the need for these elements will become greater. However, there are not enough reserves of precious metals for the entire fossil fuel-based generation to be replaced by renewable energy, including solar. Re­using elements could be one of the primary solutions for the production of solar en­ergy to match the anticipated global demand in the future.

Increased profits, enhanced job prospects and cost savings are the key consequen­ces of developing a circular solar economy. The manufacturers may be able to re­duce production costs by reusing preci­ous elements recovered from retired panels. Given the magnitude of solar waste expec­ted to be generated, third-party recycling could become an independent segment of the solar industry and provide sustainable livelihood opportunities, especially in deve­loping countries.

Building a circular solar ecosystem

A circular solar ecosystem has three foundational factors that need to be developed – technological expertise, economic maturity, and regulatory support. At present, a circular solar economy is largely a theoretical concept with little on-ground progress. Only a handful of companies are engaging in buybacks or refurbishment of solar panels after the end-of-life is ac­hieved. The market is also at a nascent sta­ge at present since the number of retir­ed solar panels is very low. However, this may soon change.

In 2019, the world generated 720 TWh of solar power, accounting for 3 per cent of the total power generation, using 46 million metric tonnes (mmt) of solar panels. It is expected that by 2026, around 70 GW of solar power capacity will be ready for decommissioning every year. As per estimates, around 8 mmt of decommissioned solar panels could be accumulated by 2030. Technological expertise that can re­furbish solar panels at scale will be re­quir­ed to tackle such massive quantities of so­lar waste. While other components su­ch as aluminium frames, glass, ethylvi­ny­la­cetate and backsheets are also used, the rare earth metals used in manufacturing the ce­lls and other metals such as copper can justify the refurbishing costs. In some cas­es, general e-waste recycling processes are being employed for solar waste management but there is a strong need for research and development in this area. Veolia, a French waste management company, has developed a recycling line specific to solar panels. ROSI Solar, an­other French enterprise, has created a process to extract precious metals from used panels.

Standards and regulations will be re­quired to sustainably extract the reusable materials from solar panels. Moreover, the un-recyclable materials will also have to be sustainably discarded so as to prevent waste. Initially, manufacturers and waste managers may have to be incentivised to encourage the recycling of solar panels. In India, which is looking at 8-10 GW of solar capacity deployment every year by 2030 through the tendering route, sustainable solar waste management guidelines and requirements at the end-of-life of a project could be built into the tender me­chanisms. This may make it mandatory for developers to put in place solar was­te ma­nagement mechanisms and encourage solar recycling.

The ecosystem will require low-cost investments to effectively develop the required technology and provide recycling and reuse services at affordable prices. Climate finance may be required in the form of public-private partnerships. Initially, government efforts might be nee­ded to push the mandates and set up facilities. However, the future of the circular solar economy lies in engaging with the private sector. It may be necessary for large-scale solar manufacturers to de­velop this technology using low-cost investments to ensure in-house circularity of the process. Alternatively, third-party recyclers may be encouraged to develop a technological core competency, which may further be licensed to provide de­centralised recycling systems. Many te­chnology start-ups are taking positive steps towards this.

Challenges and outlook

The price volatility of metals extracted from used solar panels could create a ch­allenge in determining a standard economic model for recycling of solar waste. Moreover, technologies are being explo­red for replacing rare earth elements in the solar cell development process, whi­ch, if popularised, may make the investments in the circular solar economy un­jus­tifiable. Further, quantification of the sustainability quotient of solar panel production and recycling is not currently avai­lable, which may be able to provide a definite direction for creating the circular solar economy.

Every solar panel ever deployed presents an opportunity for recycling and can play an important role in building a circular solar economy. According to Mercom In­dia, it is ex­pected that the global solar ca­pa­city may increase to around 3,000 GW by 2030. The amount of solar waste generated during this period and beyond presents a colossal challenge to the sustainability of the sector and the environment. It is, therefore, the right time to build mechanisms, technologies and processes to en­able a circular solar economy and make solar more sustainable.