Solar Waste Generation and Recycling: Where Are We Heading?

India is witnessing two important developments: an increased impetus for transitioning from fossil fuel-based energy to renewable energy and curbing reliance on China, and establishing its dominance in solar power. That explains India’s ambitious goal of generating 280 gigawatts (GW) of electricity from solar energy. Recent statistics tell us that India is sincerely pursuing its ambition, with the country’s module manufacturing capacities exceeding 39 GW at the end of September 2022.

With the Government of India throwing its weight behind the idea of domestic manufacturers ramping up local manufacturing and competing in global market, India is poised to become a dominant player in the market. Riding on government incentive programs and research & development, solar module manufacturers in India are already looking forward to expand production capacities.

These are all encouraging signs! 

But are we missing the woods for the trees? Maybe. Otherwise, how is it that we do not see equal emphasis given on a lurking problem: handling of thousands of tonnes of solar panels that will reach the end of their lives in the next few years and thousands of tonnes of solar waste that India will continue to generate in the coming years. 

What is solar waste?

Solar modules have a lifespan of 20-25 years, after which they slowly degrade in terms of efficiency and do not generate the amount of electricity they used to do. It becomes unfeasible to maintain and operate the solar modules and hence, the need arises to discard them in an environmentally-responsible manner or recycle. But before we get into the specifics of handling solar waste, let us understand what do these solar modules consist of. 

Any clean energy technology depends on metals and non-metals with varying levels of toxicity. Hence, dumping the waste equipment in the open is a risky proposition with high probability of toxic elements leaching into the environment and entering food chain. Solar technology is no different. 

The most common and efficient solar modules are made of crystalline silicon, which contain some amounts of metals, including lead, cadmium, silver, and copper. They also have longer lifespan as compared to other varieties, including the thin-film solar panels. The thin-film modules contain two different types of semiconductors—cadmium telluride (CdTe) or copper indium gallium diselenide (CIGS)—along with glass, plastic, or metal.

Composition of crystalline silicon module. Source: European Commission

It is a no-brainer that lead and cadmium, if present in high levels, can be precarious for human health and the environment. Their presence in solar modules make its waste hazardous, which makes it necessary to handle and dispose of module waste responsibly.

Recycling end-of-life solar modulesGlobally, solar module recycling follows a three-step process: 

1. Disassembly: This is the first step wherein metal frames and cables are removed from the laminated structure, either manually or automatically. 
2. Delamination: This is perhaps the most challenging part of the recycling process, which involves separating the glass layer, encapsulant, and the backsheet from the solar cells. 

3. Metal recovery is the final step in the recycling process, which involves extraction of valuable metals from the modules. 

Recycling end-of-life solar panels has the potential to unlock a huge reserve of valuable materials in the future, with ​​the International Renewable Energy Agency (IRENA) estimating that the worth of recoverable materials in old solar modules will be $15 billion by 2050.

Solar waste in India

India could generate 50 thousand-325 thousand tonnes of cumulative solar waste by 2030 and more than 4 million tonnes by 2050, according to a 2016 report by the International Renewable Energy Agency. Between 2045-2050, India could become one of the leading solar waste producers globally.

With no protocols or systems in place for collecting end-of-life and decommissioned solar panels, owners of solar modules have been discarding them wherever they are used and eventually, they would get mixed with domestic solid waste and end up in landfills. A recent media report highlighted India’s challenge of growing informal handling of photovoltaic waste. “Only about 20% of the waste is recovered in general; the rest is treated informally. As a result, the waste often accumulates at landfills,” the media report observed. This waste causes acidification, leaching of toxic metals into the soil, and contamination of water.

Lately, there has been some development in the space with the Ministry of Environment Forests and Climate Change including Solar modules and cells in the revised draft E-waste rules on May 19, 2022. This made India one of the first countries to come out with a national policy on solar waste management. 

While this is a positive step towards recycling and reclaiming the materials, and reducing carbon footprint, some experts have expressed concern over clubbing of solar waste with other e-waste. They argue for formulation of provisions specific to solar waste treatment within the e-waste guidelines.

Which countries are generating maximum solar waste?

The International Renewable Energy Agency (IRENA) estimated that the global solar waste will touch 78 million tonnes by 2050, with China, the United States, and Japan are expected to be the top three waste creators, followed by India and Germany. According to an energy research consultancy, Rystad Energy, solar waste is projected to grow to 27 million tonnes per year by 2040.

If IRENA’s predictions are to be believed, by 2050, China will generate about 20 million tons of solar waste — the largest amount of solar waste in the world. Following close is the US, which, according to the US Environmental Protection Agency, is expected to generate an estimated 10 million tons of end-of-life panels by 2050. According to the Union of Concerned Scientists, “Only 10% of solar photovoltaic panels are recycled today in the US, and the rest meet their inglorious end in the garbage heap. Among those that are recycled, very few have 100% of their material recovered.” 

Japan is equally concerned over the piling up of solar waste and the need to develop systems for disposing of this waste. New ventures are foraying into projects that address the looming challenge. Their concern is not unfounded as up to 280 thousand tons of solar modules are estimated to fall into disuse by 2036, according to the estimates of the New Energy and Industrial Technology Development Organization (NEDO). 

Germany saw a frantic growth in solar installations between 2009 and 2011. This fast growth of solar modules will be followed by the first wave of disposal around 2029, around 20 years later when the modules reach end of their lives. Presently, around 10,000 tons of silicon from discarded photovoltaic modules end up in Germany’s recycling market each year. This will increase to several hundred thousand tons per year by 2029. 

While countries explore options for effective recycling of emerging e-waste glut, current discourse is also veering towards ways to extend life of solar panels and reduce waste generation.