The solar-ready roofs piloted at Punggol Edge BTO project were inbuilt with infrastructure to enable seamless installation of solar panels to harness renewable energy for block services (Photo credit: HDB)
The Housing Development Board (HDB) in Singapore has announced that from May 2017, all future public housing blocks in the city-state will be designed with solar-ready roofs, adopting a “plug-and-play” approach to solar panel installation.
The initiative will apply to public housing blocks with at least 400 sqm of open roof space, after setting aside space needed for essential services such as water tanks, water pumps and lift rooms. It will enable more productive and efficient installation of solar panels on HDB rooftops. The blocks will be inbuilt with features to enable solar panels to be easily mounted and maintained. This move is aimed at further harnessing solar energy to power common estate services in HDB developments.
In May 2012, solar-ready roofs were piloted on the rooftops of Punggol Edge, a Build-to-Order (BTO) development. Construction of the solar-ready roofs for the six residential blocks in this project was completed in June 2016.
Right from the design stage of the project, the location of essential block services on the rooftops was strategically planned to optimise the available roof space for future solar panel installation and maintenance.
The support structures for the placement of the solar panels on the roof were also designed to integrate seamlessly with the design of the roof, blending in with the aesthetics of the block.
Electrical infrastructure for the solar panels was catered for, such as the construction of dedicated trunking for wiring throughout the block and into the switch room. By connecting the trunking directly to the roof, the need for hacking works downstream was minimised. Service access routes throughout the roof were also inbuilt to facilitate future installation of solar panels and maintenance of essential block services.
In older blocks where residents are already settled in, installation of solar panels on rooftops would require retrofitting and construction works, including re-wiring the building to link the solar panels to the switch room. Another constraint is that the space available for installation of solar panel installation is limited by the placement of the essential block services and the overall design of the roof space. As a result, more time would be needed to assess the optimum placement of the solar panels that will maximise the amount of sunlight received and avoid obstructing maintenance access to the essential block services.
In comparison, this new approach of designing the rooftops to be ready for solar panels, reduces the time and labour required for solar panel installation, making the process more efficient. On a solar-ready roof, about 25 days are required for the installation of solar panels. Compared with the 40 days required to retrofit existing blocks, the time needed for installation from start to end is reduced by about 38%. Consequently, the manpower cost for installation is also expected to reduce by more than 40%.
Following the successful implementation of solar-ready roofs at Punggol Edge, the pilot was extended to 27 blocks at Punggol Northshore (Northshore Residences I and II and Waterfront I and II) in April 2016.
Going forward, all new public housing blocks will be designed with solar-ready roofs where feasible. In addition, HDB will review developments currently under construction to assess if solar-ready roofs can be incorporated into their design. As at August 2017, a total of 18 HDB projects have been designed with solar-ready roofs.
In a separate initiative earlier this year, JTC Corporation, the country's lead agency for development and management of industrial infrastructure, awarded the first contract under a new solar leasing model, which would allow building owners will now be able to generate revenue from the use of their roof space, regardless of their own energy demands. The company would supply, install and maintain solar panels on the rooftops and pay the owner a monthly rental for the rooftop spaces. In return, the company will be able to export the electricity generated by the solar panels to the power grid, and sell it in the open energy market.