Singapore's methodical approach to becoming a net-zero city

Singapore has long taken the approach of adopting innovations methodically. The city authorities conduct pilots and demonstration projects and then scale up after recalibrating technology, delivery systems, regulations and business models. Its approach to becoming a net-zero carbon city is no different. The Singapore Green Plan 2030 outlines national strategies to become more sustainable, with actions taken on the level of buildings and districts forming part of the learning process towards achieving more ambitious sustainability goals.

The following case studies focus on "systemic efficiency", an integrated approach that includes clean electrification, smart digital technology, energy-efficient buildings and infrastructure with a circular resource economy.

The College of Design and Engineering (CDE) at the National University of Singapore is transforming its precincts. This included SDE4, the first purpose-built net-zero energy building in Singapore, completed in January 2019; SDE1 and 3, super low-carbon refurbishments of existing buildings, which will be completed by mid-2022, and a zero-carbon development, SDE2, which is still in the planning stages. This will provide more than 45,000m2 of design studios, workshops, research centres, office spaces and public spaces.

As a flagship project, the design of SDE4 combines contemporary tropical architecture with an innovative hybrid cooling system to effectively manage its energy consumption. Its entire energy demands are met by an extensive photovoltaic array on its large overhanging roof. As of January 2020, SDE 4 exceeded its net-zero energy target and is currently net-positive, i.e., supplying more than 500 MWh energy surplus to the campus micro-grid. Beyond the design intent, SDE4’s net-positive energy outcome is a result of the concerted efforts by the school’s management and occupants who ensure prudent consumption of energy. The project has also been instrumental in opening discussions on the future of healthy building design and sustainability in Singapore and the tropics.

The approach for the redevelopment of SDE1 and 3 demonstrates an effective strategy for renewing existing buildings to create low-carbon, high-comfort environments. The project aims to reduce energy demand, while also using power by on-site solar photovoltaics. The adaptive re-use approach conserves the original embodied carbon and minimizes new carbon expenditure, using less than quarter of the carbon of a new-build on the same scale.

After 12 months of occupancy, the energy performance of SDE1 has shown an Energy Use Intensity (corrected for normal occupancy) lower than 55 kWh/m2 / year. Following the installation of 422kWp capacity roof-top photo-voltaic panels, its energy production is estimated to be 15-20% higher than its consumption.

Under the Singapore Green Plan 2030, Singapore’s second largest business district, Jurong Lake District, has been identified as a model for urban sustainability. It is planned as a car-light district where at least 85% of all trips will be made by either on foot, bike or public transport. The district will also be ready for autonomous and electric vehicles.

The blueprint of the district will aim for zero emissions and waste, and will optimize land use through centralised infrastructure including a cooling system and a pneumatic waste conveyance system. The district has also adopted the Built Environment Living Lab Framework, a regulatory enabler that allows for developers and businesses to work together to pilot sustainability innovations.

Surrounded by lush landscaping and a forest corridor, the Tengah Town development creates nature-centric neighbourhoods in a holistic manner. Tengah residents can connect with nature and enjoy its intrinsic benefits, but also enjoy convenient modes of transport within and around the town. It will be home to the first car-free town centre in Singapore, with the majority of Tengah residents living within walking distance to an train station.

Residents will also benefit from having their homes cooled by a centralised cooling system, which is more energy efficient than installing individual air conditioning units. Rooftops will be installed with solar panels to tap renewable energy for the housing blocks. Sensors are installed in each home, allowing residents to have a breakdown of their energy consumption and make informed choices. All these features could translate to estimated energy savings of up to 30% for residents.

Located in the north-east of Singapore, Punggol Digital District showcases Singapore’s ambition to be a smart nation through the use of integrated master planning and technology. Part of this effort is the Open Digital Platform (ODP), a smart operating system for the district. The ODP is capable of pulling together and overlaying data from various sources, which enables control systems to “talk” to each other through an interoperable platform. The platform not only acts as an exchange for the district systems but can also simulate different operational scenarios through a digital twin. This provides a high degree of situational awareness, sense-making, control, and automation over the energy and resource performance for the district. The ODP is expected to optimise and reduce energy consumption by 15% to 30% and reduce manpower requirements of facilities and security management by 50%.

The various ambitious pilots which lead to transformation at different scales help developers, regulators and solution providers to scale up innovations. Different cities will face different constraints on their paths to net-zero, depending on inherent constraints and governance models. But Singapore’s scaled approach puts the city in good stead to be a fast learner and may offer useful lessons for other cities embarking on similar journeys to achieving net-zero carbon.

The authors would like to thank fellow researchers at CLC and NUS for their inputs, as well as contributions from Singapore agencies URA, HDB and JTC on the case studies