Making Solar Energy Cleaner
It is estimated that by 2050, the world could be saddled with 78 million tonnes of solar panel waste. It is important to ensure a circular solar energy model is economically feasible and that laws enforce proper solar panel disposal.
An hour of sun’s energy is enough to power global energy needs for a full year. Unsurprisingly, researchers have found ways to harness this abundance of energy through solar panels.
A 6.6kw solar system will produce 10,600 kWh a year which equates to eliminating 10.6 tonnes of CO2 emissions per year. After the average lifespan of solar panels of 25 years, a 6.6kw system will have a net saving of around 243 tonnes of CO2.
The cheaper cost of solar energy is also hard to resist. Electricity from fossil fuels costs between 5 cents and 17 cents per kilowatt-hour. Comparatively, solar energy only costs between 3 cents and 6 cents and is trending down.
It is no surprise that solar energy adoption rates have been on a steady rise since 1980 with its clear environmental benefits and lower costs. But this growth raises a key and pressing challenge for the solar energy industry – where do all the used solar panels go at the end of their lifespan?
A Potential 78 Million Tonnes of Solar Panel Waste by 2050
The International Renewable Energy Agency estimates that by 2050, the world would have produced 78 million tonnes of photovoltaic panel waste. Pollutants such as lead, or carcinogenic cadmium can almost be completely washed out of solar module fragments over several months by just rainwater into the soil.
“I’ve been working in solar since 1976 and that’s part of my guilt,” the veteran solar developer, Sam Vanderhoof, told Solar Power World in 2017. “I’ve been involved with millions of solar panels going into the field, and now they’re getting old.”
Recycled Material Has To Be The Cheaper Option
The biggest challenge with recycling solar panels is that it is yet to be an economical process. A 2017 study found that is it cheaper to landfill silicon crystalline solar panels which dominate 80 percent of the global market, than recycling them. This makes a circular business model an unfavourable option.
Dr Jai Prakash Singh, a senior research fellow at Solar Energy Research Institute of Singapore (SERIS), National University of Singapore (NUS), said that “the problem is that at US $18 per kilogram, silicon is cheap. To be economical, recovered silicon must (cost) less than that and have high purity.”
China, Japan, India, and Korea are driving the wave of new installations in Asia. By 2050, Asia’s solar capacity could grow to a staggering 4,837 gigawatts (GW), up from 280 GW in 2018.
To date, Japan is the only Asian country that has made efforts to promote solar recycling by subsidising recycling equipment though is not mandated. In Singapore, the onus is on developers to take back the panels at the end of its lifetime.
Efforts Have Been Made to Recycle Solar Panels
Utility firm Sembcorp teamed up with Singapore Polytechnic to develop solar recycling technology. A new method involving mechanical, thermal, and chemical treatment enables recycling rates to exceed 90% without the use of harmful acids. Both partners are looking to commission a pilot solar recycling plant within the next two years.
The technology will eventually be used to help recycle panels from SembCorp’s rooftop solar projects here, that are located at public housing blocks, schools, and government sites.
The initiatives, Sembcorp said, will help Singapore develop an approach in which solar projects will be seen through from the stages of procurement, design, and installation and operation to beyond the end of their operational lives.
Regulations Will Ensure Proper Disposal
Without adequate recycling laws, there is a risk of solar modules being carelessly discarded as manufacturers might resist internalising the cost of properly storing or recycling solar waste.
Recycling laws would stimulate innovation and support the industry by securing a steady supply of solar waste for recycling factories, allowing them to scale up operations and reach the critical mass needed to offset the costs.
If the 78 million tonnes of solar waste that will be generated by 2050 are recycled, the recovered resources could be worth over US$15 billion, IRENA estimated.