High-rise buildings account for about 90% of electricity consumption in Hong Kong, and investors along with construction companies are exploring various ways to mitigate the environmental impact of this issue.
Deep within Exchange Square – a complex located in the heart of Hong Kong – lies a mysterious underground system. This system consists of a series of pumps and pipes that use seawater directly from Victoria Harbour to cool the air conditioning systems in the area, where three office towers and a shopping center are situated above, along with the city’s financial market and several consulates.
Approximately 64,000 cubic meters of seawater flows through this system each day, which is enough to fill 26 Olympic-sized swimming pools. It operates noisily but contributes to transforming one of the world’s most densely populated cities by significantly reducing carbon emissions.
Seawater cooling system at Exchange Square.
This system also uses up to 35% less energy compared to conventional air cooling systems, leading to significant cost savings for its owner, Hongkong Land. It’s important to note that nearly half of the energy consumption in this central district is dedicated to operating air conditioning systems.
“We are pioneers in the direct seawater cooling system in Hong Kong,” said Derek Chan, the technical director of Hongkong Land. “This cooling system is automatically controlled, so you will not find any operators here.”
Hongkong Land, a unit of the Jardine Matheson Group, has been utilizing seawater since 1963 to cool its 450,000 m2 property near the harbor. The entire monitoring and management process is located on the top floor of the 52-story Two Exchange Square. Here, artificial intelligence, machine learning, the Internet of Things (IoT), and various 21st-century technological applications are centralized in a 400 square meter command center.
All of these initiatives have enabled the developer to save 30% energy and reduce carbon emissions by 40% by the end of 2021 compared to 2008, when the first comprehensive energy audit was conducted.
Andy Yeung, director and head of technical services at Hongkong Land, mentioned in an email interview: “Working with existing buildings presents many challenges, but we are determined to overcome these challenges with new technologies and systems.”
A panoramic view of Hong Kong.
Hong Kong has over 10,000 high-rise buildings, including more than 2,000 skyscrapers taller than 100 meters. It is no surprise that these tall buildings are becoming a major source of carbon emissions for the city.
According to the 2021 policy address by former Chief Executive Carrie Lam, buildings account for about 90% of electricity consumption in Hong Kong. She emphasized the importance of green buildings in reducing energy demand as part of the government’s efforts to achieve net-zero carbon emissions by 2050.
The government has set the target to reduce electricity consumption in commercial buildings by 30% to 40% and in residential buildings by 20% to 30% by 2050 compared to 2015 levels. They hope to achieve halfway towards these targets by 2035.
Electricity consumption by demand in Hong Kong in 2019.
Electricity production is also a major source of emissions in Hong Kong. It accounted for about 60% of total emissions in 2020, releasing approximately 20.4 million tons of carbon dioxide into the atmosphere, according to the latest data released by the Environmental Protection Department in June. Other major sources of emissions include the transportation sector at 19.7% and waste management at 8.7%.
Another major commercial property developer in Hong Kong, Swire Properties, has launched the Green Performance Pledge. This initiative covers the entire rental cycle, from installation areas to the operation of offices, to help improve the “carbon footprint” and enhance energy efficiency.
The real estate consulting firm JLL has installed a smart metering system in its offices as part of the plan. This system helps monitor energy usage across different areas. JLL found that nearly half of the electricity was consumed outside of business hours. Consequently, they eliminated unused equipment such as ice machines, resulting in a 9.3% reduction in energy usage in areas and cafés from October last year to June this year.
This real estate consulting firm is also researching the possibility of raising the average room temperature of air conditioning in server rooms and will replace all existing lighting systems – over 1,000 bulbs – with LED lighting.
The asset management firm based in the Netherlands, APG Investments Asia, which currently leases offices from Swire Properties, has also joined the Green Performance Pledge and aims to manage a 10% reduction in carbon emissions annually in its new office. This includes using motion sensors to turn off electrical devices and maximizing daylight usage throughout the office.
Swire Properties is also developing a smart waste reduction program by installing smart scales under trash bins to collect recycling data and manage office waste. Simultaneously, they use displays connected to the data system to publicly share the waste reduction progress of participating units.
A seven-month trial involving 15 teams from seven office towers managed by Swire Properties helped reduce waste per employee by 14%. This program is estimated to have saved 51,847 kg of carbon dioxide emissions, equivalent to planting 1,250 trees.
A building featuring typical air conditioning units in Hong Kong.
The engineering technology company Negawatt Utility has chosen to develop a digital-focused platform to manage the carbon emissions of buildings.
Arthur Lam, CEO of Negawatt, said: “With IoT and data analytics, we can understand how the building operates and make recommendations on how to fine-tune it, such as why buildings are sometimes too hot or too cold.”
The company collaborated with Schroders Capital in 2019 to conduct a pilot project at Worfu, a community shopping center in North Point. Since then, the launch of the project has helped reduce energy usage by approximately 200,000 kilowatt-hours (kWh) – equivalent to 14 tons of carbon emissions – through optimizing chillers.
Air conditioning accounted for 28% of electricity consumption in Hong Kong in 2019, according to data from the Electrical and Mechanical Services Department. Therefore, a group of doctoral students and researchers from City University of Hong Kong has sought to minimize air conditioner usage.
They established the company I2Cool in June 2021 and launched their first product, iPaint, a cooling paint that can lower the surface temperature of buildings. This patented paint, inspired by the self-cooling skin of the Sahara silver ant, reflects over 95% of solar radiation and emits infrared heat.
Air conditioning accounted for 28% of electricity consumption in Hong Kong in 2019.
Martin Zhu, co-founder of I2Cool, stated that compared to regular white paint, iPaint can create an instant cooling effect of 4 to 7 degrees Celsius when applied to rooftops. Using one square meter of iPaint can save 120 kWh of electricity and eliminate 70 kg of carbon dioxide emissions annually, equivalent to planting six trees, according to the company’s website.
Additionally, reducing carbon in buildings – the emissions associated with materials and construction throughout the entire lifecycle of a building – is also a crucial factor for decarbonizing the construction environment.
Therefore, construction companies and contractors like Gammon Construction have been using materials with lower carbon emissions. The company has over 480 certified low-carbon concrete products, with carbon emissions lower by about 15 to 30% compared to conventional concrete, according to CEO Kevin O’Brien.
“The reason why concrete is a challenge is that part of its formula is cement, and producing cement uses a lot of energy, both for extracting raw materials and the energy needed to produce cement,” O’Brien said.
According to the research organization Chatham House based in London, cement production accounts for about 8% of global carbon dioxide emissions.
