In Hong Kong, buildings account for over 90% of electricity usage, creating over 60% of the city's carbon emissions. One of the critical measures to achieve the carbon neutrality target is to reduce coal-fired and natural gas-fired electricity generation, while increasing the proportion of electricity production from renewable energy. As a pioneer in renewable energy research, PolyU spares no effort in developing relevant technologies with applications and testing on the campus. A good example is the installation of solar photovoltaic systems at the Lee Shau Kee Building (Y-Block).
“Due to the high land price in Hong Kong, it is impossible to mount photovoltaic solar panels on the ground as in mainland China,” says Professor Yang Hong-xing from the Department of Building Environment and Energy Engineering of PolyU, who has been conducting research on renewable energy applications for more than 30 years. “Therefore, we have to adopt the building-integrated photovoltaic (BIPV) technology here. By integrating photovoltaics into the building envelope on a massive scale, we will be able to minimise carbon emissions and create a green campus.”
Currently natural gas dominates the fuel mix for electricity generation in Hong Kong at around 50%, and coal, with high carbon emissions and causing high levels of pollution, accounts for 25%. Non-fossil fuels, including imported nuclear power and renewable energy, only account for a quarter, but less than 1% from renewable energies. We are particularly lagging behind other developed countries like Japan and Germany in adopting solar energy and wind energy, and there is even no comparison with mainland China.
Therefore, the “Towards a Better Hong Kong: Pathways to Net Zero Carbon Emissions by 2050” report published by the HKSAR Government urges to take an active stance in adjusting the electricity generation fuel mix, including a substantially increased share of renewable energy sources to eliminate 70% of carbon emissions. The report also refers to a PolyU research report which suggests that 10% of electricity in Hong Kong can be generated from renewable energy sources, including solar and wind power.
“Since coming on board at PolyU in 1995, I began to develop experimental systems on solar photovoltaic integration in buildings,” says Professor Yang, who set up Hong Kong’s first BIPV experimental system on the PolyU campus in 1999. An 8-kilowatt photovoltaic system was installed on the roof water tank of Shaw Amenities Building (Block VA) to absorb energy from the sunlight for power generation. Later, the same kind of device was also installed on the roof of Tang Ping Yuan Building (Block F-C) for testing different kinds of BIPV systems.
Leading projects implemented on the PolyU campus not only brought demonstrative effects to the society, but also raised the attention of the Government and the industry, and attracted many visitors to the sites. More BIPV systems were consequently set up in different locations of Hong Kong by the Government and industrial organisations, which further demonstrated how BIPV works. Since then, Professor Yang has helped design and install BIPV systems for various development projects at the Kadoorie Farm, the Hong Kong Jockey Club and Ma Wan Park. This significantly promoted BIPV and drove the development of renewable energy technologies in the territory.