SINGAPORE - A new aircraft hangar at Changi Air Base East will produce 30 per cent more electricity than it uses, as part of the Singapore Armed Forces' drive to help meet national targets in tackling climate change.

This is possible through the use of solar panels installed on the hangar's rooftop, as well as reducing energy and water consumption with features to maximise natural ventilation and harvest rainwater.

The hangar for the Republic of Singapore Air Force's A330 Multi-Role Tanker Transport (MRTT), which took two years to build and will be completed later this month, is the Singapore Armed Forces' first net positive energy building.

Defence Minister Ng Eng Hen on Monday (March 2) said the SAF plans to install solar panels on buildings in 12 other camps, which would generate enough electricity to power 5,500 four-room HDB flats, and net about $1.6 million in cost savings annually.

In addition, the Ministry of Defence has commissioned net zero energy buildings - the Ordnance Engineering School building in Kranji Camp III and the headquarters Army Combat Engineers Group building in Seletar Camp - which are fully solar powered.

The green features in these two buildings, the MRTT hangar, and the installation of solar panels in SAF camps is expected to reduce 11,400 tonnes of CO2 emissions by March 2021, Dr Ng told the House during the debate on his ministry's budget.

He said the SAF will also replace 400 administrative vehicles - first with hybrid models, reducing emissions by up to two-thirds per vehicle - and later with electric ones when the island's charging infrastructure is built.

In another effort, a joint collaboration between the SAF, National Environment Agency and the Defence Science and Technology Agency (DSTA) resulted in a waste management system to turn recycled food waste into energy.

Food waste collected from eight cookhouses currently is processed by microbes and enzymes at recycling plants to generate biogas. This will be expanded to 10 more cookhouses, and to all cookhouses if successful, said Dr Ng.

To counter the effects of rising sea levels, Mindef is working with agencies like the Housing Board on Singapore's first polder development at Pulau Tekong - first announced in 2016.

The polder comprises a dike which protects reclaimed land from the sea, and a network of drains and pumps to keep the land dry. The reclaimed land can be used for army training, he said.

The SAF could also reap operational advantages by adapting to "green" technologies, said Dr Ng, citing the navy exploring the use of hybrid propulsion systems in designing its incoming vessels.

"Such technologies enable our new ships to not only reduce carbon emissions, but become more energy efficient than the ships they are planned to replace."

As for the MRTT hangar at Changi Air Base East, it attained the Building and Construction Authority's Green Mark Platinum (Positive Energy) award last month.

It measures 85m by 90m, with a height of around 35m.

In a media preview last Saturday (Feb 29), Military Expert 6 Teo Keng Siang, 44, who heads the Infrastructure and Systems Branch at the Air Plans Department, said the air force worked closely with the DSTA to design the hangar.

Solar panels installed on its rooftop generate 1,225 megawatt-hour of electricity a year, which is enough to power 273 four-room HDB flats.

Rainwater is harvested and recycled for washing, the flushing of toilets, and irrigation of the hangar's "green" roof, which uses carpet grass to act as an insulation layer so that heat build-up can be prevented.

The building is also positioned in a north-south orientation, in line with the predominant wind direction to optimise air flow for natural ventilation. In addition, LED lighting and air-conditioning used are also designed to be energy-efficient.

With these, the hangar is expected to use about 900 megawatt-hour of electricity a year - about 30 per cent less than what it generates. The additional electricity generated will be used to supplement other energy demands within the air base.

Mr Soh Tian Boon, 46, senior programme manager for Transport Aircraft Infrastructure at the DSTA, said surveys will be done to see if energy used is as calculated. "We are quite confident of our design," he added.