Carbon Emission Reduction Measures and Strategies

• Representatives from various divisions and service providers across CAD’s network have participated, through regular meetings, in the implementation of a 5-year energy saving plan to reduce energy consumption by at least 6% from FY20/21 to FY24/25 and a carbon management plan to achieve net-zero carbon by 2050.
• By active participation in pledges, campaigns and events related to environmental protection and sustainability organized by HKIA, HKAEE, CLP and professional bodies and publication of annual environmental reports in our website, CAD has showcased our environmental achievements to the public including the aviation trade.
• Promotion, training and visits have been organised for staff to gain insights into the best environmental practices and advanced green technologies, which enrich our knowledge and foresights.
• CAD has endeavored to adopt innovation and technology in decarbonisation. It used artificial intelligence to augment energy optimisation systems, in order to enhance the cooling efficiency of chiller plants across its operations. Meanwhile, a pilot trial of immersion cooling system for the control tower simulator is being conducted to evaluate energy saving performance for the planning of any scaled-up applications.
• CAD has implemented a comprehensive plan to reduce, recycle and reuse wastes such as paper, glass bottles, plastic materials, rechargeable batteries, rain water and cooling tower water condensates.
• Electrification of all vehicles is part of CAD’s long-term commitment to reduce carbon emissions, and presently 80% of its fleet of vehicles used across operations are electrified.
• CAD has progressively decarbonised its daily activities to combat global warming, through green housekeeping measures, energy and carbon audits and site walks. It has also installed PV panels to capture clean energy, and replaced less efficient air conditioners, conventional lightings and other equipment.

Case Study: AI Optimization and Advanced Cooling Technologies for Decarbonisation

Application of AI in Decarbonisation
The water-cooled chiller system of the A/C system serving CADHQs is already equipped with an Energy Optimisation System (EOS) to optimize its cooling efficiency. CAD further advanced the EOS to Artificial Intelligence-Energy Optimisation System (AI-EOS). The operational parameters of the A/C system including chiller sequence control, cooling tower sequence control, cooling water supply temperature control, secondary chilled water system pressure control, and chilled water supply temperature control are fed back to the control system for modelling and prediction using Artificial Neural Network (ANN) technique and optimisation of energy consumption using Particle Swarm Optimization (PSO) technique. After a period of measurement and verification, the AE-EOS has been put into full operation. With the application of AI, an optimisation of efficiency by 3.0%, on top of the EOS, has been achieved.

Exploring Two-phase Immersion Cooling for Decarbonisation
Since early 2023, CAD has studied the technical feasibility of application of the two-phase immersion cooling for mission critical and large-scale systems. A pilot trial on applying two-phase immersion cooling system in CAD’s Control Tower Simulator (CTS) commenced in April 2024 on pilot trial setup implementation.

Utilising the two-phase immersion cooling technology, heat generated from the electronic components is efficiently transferred to the dielectric coolant when it changes from liquid to vapour phase upon reaching its boiling point. The rising vapour is then cooled by a circulating coolant at the top of the container and is condensed back into liquid droplets. The cycle of heat transfer, dissipation and condensation repeats to maintain the operating temperature of the electronic components.

The energy efficiency data and operational data will be collected to evaluate the cooling capability and explore its operational practicality, pros and cons for planning of any scaled-up application in the future.