Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur eleifend tortor nec augue pretium
Recent advances in sensing technologies and data-driven applications have increased research on digital twins (DTs) in the built environment. A DT provides a virtual representation of a physical object or system, such as buildings, allowing real-time monitoring benefits.
However, the use of DTs for carbon neutrality is relatively limited in built environment research. From the practitioners’ perspective, most of the focus is on monitoring indoor data sensors, construction progress and construction safety. Although the potential in the built environment is enormous, inadequate attention to net-zero research may hinder a DT in achieving its optimal prospects. In our study, we explored the nexus between DTs and net zero in the construction body of knowledge to gain a broader picture of the prominent and under-researched areas.
Explaining the concept
The concept of DTs evolved from the aerospace and manufacturing industries. Essentially, they comprise of three main characteristics – a physical object, digital representation and a two-way connection.
In construction, the physical object refers to buildings, infrastructure, components and materials, and the digital representation refers to virtual models or building information models (BIM).
The two-way connection refers to bi-directional information transfer using sensors between the physical and virtual objects in real time (see right).
Uses for net zero
A scientometric analysis was conducted to quantitatively map topics explored in the literature on the intersection between DTs and net zero – the analysis resulted in 61 nodes (keywords) and 942 links.
Regarding prominent nodes, IoT, energy efficiency, carbon emissions and energy utilisation are part of the nodes with the largest sizes and connections to other topics. IoT shares strong link strengths with carbon emissions and energy efficiency, however, the strongest link strength in the network is between carbon emissions and carbon neutrality.
While this occurrence underpins the motive to use sensing technologies to monitor emissions, it further highlights researchers’ interest to digitalise emissions assessments as the intelligence of buildings increases.
Furthermore, topics that are under-researched include digital storage, energy computing, big data, blockchain and renewable energies.
Based on the articles extracted, similar topics were synthesised to generate broader themes for comprehensive discussions: building energy, emissions assessment, artificial intelligence (AI) and solar energy.
Building energy: While DTs have been used to enhance inter-sharing processes for energy sharing among building stocks, other studies applied DTs to monitor and understand the energy savings from net-zero energy buildings . Energy-efficient manufacturing DTs (EMDT) are another application that is emerging for handling uncertain energy behaviour in buildings.
Emissions assessment: Zhou and Zheng (2024) used DTs as an integrated platform to simulate material-component-district building analysis for decarbonisation quantification. The majority of past studies used DTs as an integrated platform to improve accuracy of carbon footprint accounting from multiple-source data and monitor emissions from existing assets. Another area of interest is near real-time dynamic energy performance certificate. In this regard, Koltsios et al. (2022) explored how DT data framework can facilitate automated carbon-neutral buildings.
AI-enabled infrastructure: DTs offer two leveraging benefits – access to large dynamic data and machine learning opportunities. In that regard, AI in DTs has been applied in energy demand management, specifically to balance supply and demand under diverse situations for building stocks. Increasing the intelligence of buildings is crucial to achieve a positive energy building. AI has been integrated in DTs to maximise passive and active systems, improve material selection and develop building envelop designs .
Solar energy: Reducing non-renewable energy sources in energy supply is a vital artery to achieve net-zero targets. Solar energy is the most discussed alternative energy source in the DT and net-zero building literature. Particularly, detecting faults in solar photovoltaics and building integrated photovoltaics performance have been explored in DTs for carbon neutrality Other studies focused on the trade-off between building comfort level and PV battery remaining energy in a DT-enabled platform.
Research gaps and future needs
Blockchain: The integrity of data transferred within the DT-net-zero platform is crucial for real-time information sharing. However, the emerging DT research has not evidently explored the core attributes of blockchain (i.e. immutability, transparency and trust) regarding the multiple sources of large data transacted in DTs. Since the majority of net-zero buildings would depend on multiple or hybrid forms of energy supply, having an immutable system for information sharing would be beneficial to facilitate trust among individual and community-wide energy demand management.
Other renewable energy resources: Although some past studies explored solar energy, there is little attention on integrating other types of renewable energy in the DT-net-zero literature. While most studies acknowledge hybrid energy supply as the significant path to net-zero buildings, this is not strongly evident in the emerging literature. The assumption that IoT research explored renewable energy sources would not help optimise the potential of DTs in the net-zero agenda. This is because DTs offer a two-way information transfer which would help in developing effective interventions automatically to either reduce or avoid energy wastage. Future studies can focus on developing automated interventions in DTs to be implemented on other renewable energies regarding net-zero buildings.
Cost effectiveness: The cost implications of implementing DTs for net-zero buildings have been considered in the current literature. Multiple sensing technologies have been applied to monitor and evaluate building environments. However, investing in heterogenous sensors for monitoring and decision-making interventions without clear evidence of cost savings or benefits would impede the adoption of DTs in net-zero buildings. Perhaps, this could be one of the major challenges influencing the practical applications of DTs in net-zero buildings. Developing cost-saving estimating models associated with the automated interventions in DT-net-zero buildings would be an efficient pathway for future research to justify DT adoption.
Conclusion
While the majority of studies in net-zero research focus on IoT sensors to address several issues, research is relatively limited , with energy control and emissions prediction having dominated the literature. However, research areas that would further improve DTs in net-zero building research include blockchain applications, other renewable resources integration, and cost-savings evidence. The finding in the study provide valuable insights for researchers to comprehensively improve DT applications towards a net-zero built environment.
The study won ‘best paper’ at the SEEDS 2024 Conference, and was authored by Sitsofe Yevu, Chris Gorse, Patricia Carrillo, and Kambiz Rakhshanbabanari, from the School of Architecture, Building and Civil Engineering at Loughborough University.
