IES developed a Performance Digital Twin model of the super-efficient Green Mark Platinum Keppel Bay Tower building and achieved an additional 7% kWh/m2 annual energy savings from better operation and control. The Digital Twin was calibrated to accurately reflect the energy performance of the actual building using a live link to its operational BMS data.
IES was one of five technology partners in an innovation project jointly funded by the Building Construction Authority and Keppel Land in Singapore. The aim of project was to use innovative technology to achieve energy savings beyond the more traditional measures already implemented in the Keppel Bay Tower (KBT) building and go beyond the Green Mark Platinum standard, which is currently the highest building performance rating that can be achieved in Singapore.
This $1.28 million grant from BCA was to testbed new and emerging technologies which would reduce the building’s energy consumption significantly and improve its energy efficiency by 20% compared to other Green Mark Platinum buildings by June 2020. The goal, which has been achieved, was to reduce the annual energy consumption of Keppel Bay Tower to 115 kWh/m2 per annum from its initial consumption of about 145 kWh/m2 per annum.
The Keppel Bay Tower is an 18 storey 394,000 sqft commercial building located at the Harbour front in Singapore’s Central Business District. IES’s role in the project focused on delivery of a highly calibrated Digital Twin model, which accurately reflected the current performance of the building, using live operational Building Management System (BMS) data. At IES we call this a Performance Digital Twin, as it takes the existing VE model and replaces building assumptions with real metered data which then produces a realistic physics-based digital representation of the building in operation, enabling better informed decisions to reduce energy consumption. In this case the physics-based model was used to fully analyse the building’s performance and identify a range of twelve energy savings opportunities for the building. Of these a final eight were installed and energy savings of 7% kWh/m2 per annum were measured and verified as being achieved.
IES carried out site visits and connected to multiple data-sources on-site to continuously collect and import data into its iSCAN platform which relays the building’s performance in real-time to the virtual Digital Twin. The model was calibrated to ensure it was over 99% accurate and used to identify and virtually test the impact of a range of viable energy conservation measures (ECMs). As the other four technology partners were focused on installing new retrofit applications in the building, IES’s measures could only focus on identifying energy savings resulting from optimising the existing operation of the building.
Through the use of the digital twin IES initially identified twelve viable ECMs to be implemented in the building. After consultation with Keppel Land and their BMS supplier, eight of these suggested ECMs were then implemented in the building over a 3 month period which resulted in a measured EEI (kWh/m2 per annum) saving of 7%. The measures installed were mainly low/no costs measures, achieved by making changes to the operation of the existing BMS. These included improving the chiller sequencing and ACMV plant operation, new VAV static pressure settings, increasing space thermostat settings on all floors, and applying a CWH reset up until 12oC.
To ensure the building does not operationally drift from this new optimal configuration, IES developed a continuous monitoring system using a combination of an interactive 3D model and online dashboards which display information about the project, information on each partner, key performance indicators and the savings achieved as confirmed through various Measurement and Verification (M&V) processes.
A fault detection system integrated into this was also developed by IES, using a set of rules and predictive analytics specific to Keppel Bay Tower. This enabled automated and continuous identification of sub-optimal or faulty operation in the building, as well as daily feedback to the building operators on optimal set-points for the day ahead.
Mr Hugh Lim, CEO of Building and Construction Authority, said, “The efforts for Keppel Bay Tower demonstrate a good example of how even existing large commercial buildings can tap on innovation to achieve Super Low Energy (SLE) status, by combining smart air-conditioning and lighting with integrated controls. The reduced energy demand can be met by renewables harnessed onsite and offsite through Keppel Land’s holistic approach. We hope more building owners and industry players will be inspired to set new benchmarks for how we build and operate buildings – new and existing - contributing to the urgent task of mitigating climate change through Super Low Energy Buildings.”
This initiative is part of Keppel’s continued efforts to transform Keppel Bay Tower into Singapore’s first Super Low-Energy High-Rise Existing Commercial Building. It was the first time that any of these technologies were implemented in a development in Singapore. This has resulted in overall energy savings of about 2.2million kWh per year, or a 30% reduction in yearly energy consumption, compared to its 2017 Green Mark Platinum level. At this stage, KBT’s annual energy consumption is half that of a typical office building in Singapore, resulting in electricity cost savings of around $400,000 annually.
Source for all measurements and statistics: KBT- Singapore First_s Green Mark Platinum _Zero Energy_ Commerical Building _High-Res_5 Dec 2022.pdf (sleb.sg)