Energy efficiency on the equator

The discussion of how to increase energy efficiency often turns to the building sector, where a great deal of energy is used for space and water heating, at least in Europe.  Having seen plenty of energy efficiency projects in northern and western Europe in recent years I’ve grown accustomed to some of the energy efficiency technologies that that are commonly used  by housing associations, local governments and other institutions to drive down costs and emissions.

However I recently travelled to Singapore to shoot a series on the development of cities and was able to see how the issue is dealt with from a completely different, equatorial perspective. If you’ve never been there, Singapore is really very warm all of the time. Even at night it rarely dips below 18 degrees and in the day the temperature hovvers around 30 degrees, and that’s pretty much it for weather – hot and warm, or dry and warm. There isn’t any demand for space heating and even demand for hot water is lower than the UK, where I come from. The big issue is how to keep buildings cool.

Now Singapore isn’t exactly a paradise for fans of low-emissions green technologies, as the city seems to survive on fossil-fuel powered air conditioning, but that doesn’t mean that there aren’t new and innovative approaches to energy efficiency being put into action. One Saturday morning we went to the north of the country to see a new development called Punggol, a kind of ‘eco-town’ built by government authorities to explore how energy efficiency measures can be put into practice.

These measures include some quite simple ,and some would say obvious, changes to how apartment blocks are built. For example, the buildings are oriented towards the prevailing north-easterly wind, and on an east-west axis to limit the solar gain inside. The apartments have high ceilings, and windows positioned to encourage north-south airflow. The residents I talked to try to keep their air conditioning use to a minimum, mostly at night so they can sleep comfortably.

On the roofs you’ll find a jumbled layer of paving slabs that acts as a thermal shield, with the slabs raised a foot off the surface to allow air to circulate below and again keep the solar gain to a minimum. The slabs look like they’ve been scattered across the surface of the rooftop willy nilly, but in fact they are carefully positioned to channel rain water down into the main municipal water catchment channel.

On one of the blocks we were also shown a site where the housing authority is testing tubs of different plants to see how well they protect the buildings against the heat. The plastic containers tesselate nicely and contain their own drainage system so they can make a low-maintenance natural barrier. The local architect told us that the plants can reduce the ambient temperature around the building by up to two degrees, and can cut the surface temperature of the building by over 15 degrees.

It’s not rocket science, but it works, and is exactly the kind of easy to apply, low-cost solution that makes a genuine difference to the energy costs of the building.