Trial / Demo
In this article, featured in the latest issue of Energy Future magazine, Rohan Rawte envisions how digital replicas of physically built structures can help predict their lifespan, resilience, and operational emissions through simulation and real-time data. The successful implementation of digital twins in Singapore’s prominent commercial complex gives a glimpse of the future of low-emission and more resilient buildings.
Globally, buildings account for 34% of global energy and process-related CO2 emissions, while also being responsible for 32% of global energy demand. Concerns around energy security and costs have risen in recent years, after successive political and economic pressures culminated in full scale global energy crisis.
Poor performing buildings not only lead to energy waste, but also result in increased operating costs, CO2 emissions, reduced asset value, and negatively impact the health, well-being and productivity of their occupants. Understanding areas of energy waste within buildings is an important first step in reducing the overall energy demand, as well as providing quick wins across aspects like energy resilience, emission reduction and costs.
To curtail the impacts of climate change, India has committed to achieve net-zero carbon emissions by 2070. However, current projections indicate that emissions from buildings alone between 2020 and 2070 will exceed the carbon budget allocated for the entire country by 2%.
Fortunately, opportunities exist to address this. Building energy efficiency presents a solution to address these issues simultaneously. In a report published by the Center for Study of Science, Technology and Policy (CSTEP), annual building operational emissions could be reduced by up to 69% by carrying out energy efficient interventions. However, architects, engineers, planners, owners and operators need access to the right tools and data insights to be sure of deploying the right strategies.
This is an area where advancements in building data infrastructure, and innovative technologies, such as digital twins, are making it possible to gain deeper insights into how buildings perform across their lifecycle and help stakeholders identify where operational, and capital improvements can be made to decarbonize and increase energy efficiency.
Additionally, higher energy prices and lower technology costs are beginning to yield quicker paybacks on net-zero building interventions. However, challenges remain when it comes to de-risking these investments and calculating the long-term cost and carbon returns to build a fully informed business case for net-zero. These are all instances where having access to digital twins can provide invaluable insights to aid the transition to a more energy-efficient future.
In the present context, a digital twin can be described as a virtual replica of a building, which gathers real-time data and uses physics-based simulations to respond and behave in the same way as its real-world counterpart. It allows stakeholders to analyse how their buildings are performing now, gain insights into how they should be performing and explore different scenarios to understand the impacts of future changes. It can also provide decision support information to improve asset performance, influence future building designs and retrofitting, and reduce investment risks.
Accurate data is important for understanding a building’s energy consumption, to help establish a performance baseline and compare it to Energy Use Intensity (EUI) benchmarks. While each building is different in terms of occupants, building fabric, controls and technologies, most buildings fall short in terms of performance expectations. Utilizing a building digital twin which accurately reflects all the varying factors, and leverages data from building management systems (BMS), IoT sensors, metered data and historic files, can help identify operational quick wins, which have been shown to save 26% EUI on average in commercial building types. Optimization provides a low-cost solution to set existing buildings on the pathway to net-zero and brings the added benefit of often having the lowest embodied carbon impact of any potential decarbonization or energy efficiency measures.
Once the initial operational quick wins have been addressed, the same digital twin can be used to simulate the impact of deeper retrofit investments or renewable installations. This provides a virtual test bed for evaluating the impact of investments designed to improve the energy performance of a building, to understand the potential impacts before they are deployed in the real world. This can significantly de-risk investments and increase overall confidence in energy efficiency and decarbonization strategies.
Notably, improving building performance is a lifetime process, requiring continuous monitoring and tracking to ensure a building continues to perform as expected, preventing operational drifts and keeping buildings on track towards zero-carbon goals. This is where a digital twin can really come into its own, allowing stakeholders to ensure that the building operates optimally across all parameters, encompassing occupant comfort, carbon emissions and costs, as opposed to considering energy efficiency as an isolated factor.
Recent technological advancements are making this process much more accessible, whilst also enabling the ability to track key performance metrics on a continuous basis, as opposed to reviewing single points in time. One such solution, IES Live, is enabling this next generation approach to building energy, carbon and comfort management. As a cloud-based platform, designed to be delivered by engineering consultants as part of a whole-life building performance approach, it connects near real-time operational building data with daily simulations from a performance digital twin of the building which is hosted online. This enables a single pane view across key building data, highlighting when the building moves away from optimal performance as predicted by physics-based simulation, and delivering daily insights on the cost, comfort and carbon impacts of customized operational improvement strategies. Results are visualized through intuitive front-end dashboards so building owners, sustainability and facilities teams can see clearly whether improvements have paid off and ensure that they continue to perform optimally over time.
As a global leader in digital twins for the built environment, IES has supported many projects globally to demonstrate the role of digital twins in action. One such example is the super-efficient Green Mark Platinum Keppel Bay Tower (KBT) in Singapore, an 18-storey 394,000 sqft commercial building located at the harbour front in Singapore’s central business district.
As one of the five technology partners involved in the project, IES’s role focused on the delivery of a highly calibrated performance digital twin, which accurately reflected the current performance of the building, using live operational BMS data and physics-based simulations. 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).
Using the digital twin, twelve viable ECMs were initially identified to be implemented in the building. After consultation with Keppel Land and their BMS supplier, eight of these suggested ECMs were implemented in the building over a 3-month period, resulting in a measured EEI (kWh/m2 per annum) saving of 7%. The measures installed were mainly low/no cost measures, achieved by tweaking 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 across 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 can be monitored via the system.
An integrated fault detection system 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 operations in the building, as well as daily feedback to the building operators on optimal set-points for the day ahead.
The initiative formed part of Keppel’s continued efforts to transform Keppel Bay Tower into Singapore’s first super low-energy high-rise existing commercial building. It is the first time that a high efficiency air distribution system, an innovative cooling tower water management system, fresh air intake control system, smart LED lighting solutions, and an intelligent building control system have been implemented together in a development in Singapore. The combined efforts of the project partners have resulted in overall energy savings of about 2.2 million kWh per year, or a 30% reduction in yearly energy consumption as compared to the building’s 2017 Green Mark Platinum level. Following the implementation of the chosen ECMs, 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.
Projects like these are a reassuring reminder of the significant energy savings that stand to be gained within the built environment. And while there is no ‘one-size-fits-all’ approach when it comes to energy efficient buildings, digital twins can help find the right solutions.
Find out more about IES' Digital Twin solutions at https://www.iesve.com/digital-twins.
