The city of sustainable skyscrapers. BBC 9 February 2021 Matthew Keegan Hong Kong, the world's capital of tall buildings, is turning up the dial on high-rise sustainable design, as the city aims for net-zero emissions by 2050. Looking out over Hong Kong's iconic skyline from the viewing deck of its tallest skyscraper, the 118-storey International Commerce Centre (ICC), it's clear why Hong Kong is known as the world's most vertical city. In every direction you look, countless high-rise buildings are stacked side by side, clustered together, like a real-world version of the game Tetris. In fact, Hong Kong is home to more skyscrapers than anywhere else. While many are impressive feats of construction and have become iconic features of the skyline, the city's 42,000 buildings – including about 8,000 high-rises, of which more than 1,500 are skyscrapers exceeding 100m (328ft) in height – consume up to 90% of the city's electricity and contribute to 60% of the city's greenhouse gas emissions. With limited land supply, building upwards is Hong Kong's only option. But in a world responding to the climate crisis, towering skyscrapers that use massive amounts of energy and materials to construct and operate may look increasingly out of place – particularly given that Hong Kong itself has set a target to be carbon neutral by 2050. 

The problem leaves many asking how sustainable skyscrapers can really be. But there are signs of hope in Hong Kong, which has a thriving green building movement and is committed to making its vast number of skyscrapers more energy efficient. You need look no further than ICC, which at 484m (1,590ft) is the city's tallest skyscraper and also its tallest green building. Making use of the latest smart technologies to be more energy efficient, the ICC is recognised in the top 3% of green buildings around the globe. Inside the 118-storey building, a network of sensors is installed, often wirelessly, across different facilities and equipment, including lighting, elevators, escalators and air-conditioning units. This network provides large quantities of data that enable real-time energy consumption monitoring. Informed by the data, the property management team is able to shut down certain facilities, including lights, lifts and escalators when they are not needed, in order to save energy. "We use Internet of Things (IoT) technology to analyse big data collected through a mobile digital system for energy efficiency optimisation in the building," says Edward Tsui, managing director of Intelligent Technologies, which oversees the ICC's IoT data system. "We can see the energy performance across every zone in the building and optimise the system to perform better.
 
"It's like a body check, if you like, of the building," says Tsui. "Every single day we can monitor what the energy savings are. If we see any abnormal activities we can reset or we can do some quick maintenance before it really wastes any energy."The data collected is also used to prioritise any maintenance they do on the building in addition to retro-commissioning – a process to improve the efficiency of an existing building's equipment and systems by fine-tuning it rather than replacing it. Keeping skyscrapers cool is perhaps the most difficult challenge, especially since most are covered in glass. While floor-to-ceiling windows enable better views and natural light, this can also create a greenhouse effect caused by solar radiation, and air-conditioning systems require huge amounts of energy to operate. At ICC, air-con consumes a staggering 70% of the building's total energy. But with smart IoT devices built into the building's air-handling systems, the building's team is able to monitor each floor in real-time to see the temperature, levels of pollutants, and how much cooling energy is being used. It also means they can control the air distribution to different office floors in order to further optimise the energy usage of the building. 
 
Since 2012, through various energy saving measures, ICC has conserved 15 million kWh of energy, equivalent to the total annual electricity consumption of more than 4,500 three-member households, and a reduction of 10,000 tonnes of carbon emissions. And the team is committed to achieving the net zero carbon emissions by 2050 target set by the government. Among their plans to reach this ambitious goal is to make better use of the building's glass-covered exterior by installing solar panels to generate renewable solar energy. They also plan to utilise the winds that whip past such a tall building by installing wind turbines on the roof and podium to generate renewable energy. To further work towards zero carbon emissions, the team is looking into a battery system to store this renewable power. "There are many possibilities lying ahead and we are hopeful, especially when we talk about battery technologies," says Lewis Lam, deputy general manager of property management at ICC. "We are very certain that in the not-too-distant future we will be seeing the mass application of batteries to even conventional homes, not only large commercial buildings like ICC.
Another pioneer of Hong Kong's green building movement is One Taikoo Place. This 48-storey skyscraper, completed in 2018, was designed and constructed according to the highest green building and human health standards." The building's energy intensity is about 29% lower than a typical Hong Kong high-rise office building. This, in part, is achieved by a state-of-the-art, AI-enabled building management system called Neuron, which performs a similar role to the ICC's team but uses a type of AI called machine learning. Neuron analyses and learns from large historical datasets to automatically optimise building systems and improve energy efficiency. Among other features, the system enables optimal performance of the building's heating, ventilation and air-conditioning (HVAC) systems by forecasting when to switch on and off the chillers and cooling towers, which reduces the total building energy consumption. It can also detect, in real-time, if the building has any abnormalities, which helps prevent excessive energy consumption and operational inefficiency, while identifying when and where critical equipment needs service.....read on    https://www.bbc.com/future/article/20210209-hong-kong-