(6 September 2023 Hong Kong Free Press)
In recent years, more and more people have installed solar panels on their roofs. Solar panel owners can sell the green electricity generated by these solar panels to power companies for a handsome income. In turn, the power companies can sell renewable energy certificates to companies and organisations interested in reducing their carbon footprint.
The feed-in tariff scheme was supposed to help Hong Kong in its transition to green energy, but Super Typhoon Saola, which battered the city last Friday night, has exposed some of the weaknesses of solar energy development in Hong Kong’s urban context: the proper installation, disposal and treatment of used solar panels.
Although the inconvenience brought by Saola was not as significant as Mangkhut a few years ago, it caused chaotic scenes throughout Hong Kong. One particular danger was the solar panels being blown away from the roofs of some high-rise buildings. Many netizens took pictures and videos of broken solar panels crumbling under the roaring wind.
The solar panels installed in my neighbourhood five years ago fell to the ground during the typhoon. Fortunately, their shards did not injure anyone. Since mainstream recycling stations, like Green@Community, do not collect photovoltaic panels, these used and damaged panels are often treated as regular municipal solid waste and sent directly to landfill.
Solar panels contain valuable and recyclable materials such as silicon (glass), aluminium (frames) and copper (wires). Ninety per cent of the glass and 95 per cent of the semiconductor materials in solar panels are recyclable and reusable, while thin-film photovoltaic modules carry heavy metals such as lead and cadmium.
Improper disposal of used solar panels can cause water and soil pollution. Some countries, therefore, have already taken steps to address the potential environmental impact of solar panels upon their end of life.
As early as 2012, European Union member states passed laws requiring manufacturers, distributors and installers of solar equipment operating in the EU to collect and process used solar panels, and to recycle at least 80 per cent of the components to ensure the sustainable cycle of electrical and electronic equipment. Proper recycling systems not only cover the increasing need for sustainability but also strengthen consumer confidence in choosing green energy.
What about Hong Kong? A few months ago, hikers in Sha Chau and Lung Kwu Chau Marine Park found many discarded solar panels floating in the water. In response to media enquiries, the Environmental Protection Department said: “Solar photovoltaic panels are mainly made of solids such as glass, aluminium and semiconductors. Under normal circumstances, they do not release hazardous substances and can be disposed of as general waste.”
Although this statement contradicts what scientific facts suggest, it shows that used solar panels in Hong Kong will eventually end up in landfills.
The fate of used solar panels does not meet the expectations of their environmentally-conscious users, and authorities should look into this issue immediately to address the life-cycle of solar panels, or possibly other green solutions.
Solar panels have a lifespan of around 25 years, with their power generation capacity dropping to 80 per cent after 20 years of use. On the other hand, solar inverters, which convert direct current generated from the solar panels into alternating feed-in current, could have a much shorter lifespan of five to 10 years.
Six years after introducing the feed-in tariff scheme in Hong Kong in 2018, more must be done to create a circular system that can adequately handle and recycle used solar panels. The first wave of component replacement will start very soon. We need to act now to develop a “producer responsibility” system that would encourage proper recycling of used solar panels to prevent them from being disposed of in our dwindling landfills.
Steven Chan Wing Kit and Thomas Chan Ting Hin are members of the environmental affairs team at The Green Earth, a local environmental group. They are interested in light pollution, waste management, plastic pollution and the climate crisis. Their works hope to shape better environmental policies in Hong Kong.