What appear to be slabs of golf course sod strewn across Singapore public buses are in fact part of a pilot program attempting to ascertain if green roofs for vehicles can reduce heat waste.
As part of the "Garden on the Move" initiative launched earlier this week, Singapore has installed two patches of grass on ten city buses, each spanning 1.8 meters by 1.05 meters. After a three-month trial period, officials will examine if the vegetation lowers temperatures inside the vehicles, potentially cutting down on air-conditioner fuel use.
Oh Cheow Sheng, group director of National Parks, explained: "This is a creative initiative that seeks to extend Singapore’s greening efforts, and which truly encapsulates the vision of a biophilic City in a Garden. We hope that this will spur others to explore other similarly innovative ways to green up Singapore."
Wind-resistant plants adapted to the climate and able to thrive on minimal amounts of water were selected for the roofs. Moreover, conventional mats of growing plants would typically weigh 125 to 200 kilograms, which is a strain on the buses, so the project turned to Gaiamats, a layer of woven organic natural fibers that act as soil. Each mat only weighs 25 to 40 kilograms; the material requires less water and only needs maintenance two to three times a year as opposed to every month.
Typically reserved for buildings, green roofs can lower temperatures by 20 to 30°C, according to Dr. Terrence Tan from the National University of Singapore (NUS). If it's proven that similar effects hold true for buses, the plan might be expanded. Sensors will be placed on each roof to monitor the endeavor's effectiveness. “It’s the same as having parks—you get cooler temperatures outdoors. Collectively, if we have enough vehicles with green roofs, we could reduce temperatures and increase our thermal comfort," explained Dr. Tan Chun Liang, also of NUS.
The Temasek Foundation, National Parks Board, Moove Media, and Singapore Green Building Council contributed funds for the project. Designed by GWS Living Art, the buses operate in the city's lakeside area where the Singapore Garden Festival Horticulture Show is being held.
[Photo via Straits Times]
