Post-event report: Visit to BCA Zero-Energy Building

On the 12th of March, 20 intrepid explorers embarked on a visit of BCA’s Zero Energy Building (ZEB), Singapore’s first zero energy building retrofitted from an existing building.

What is remarkable is that the ZEB is being used regularly and was retrofitted from an existing building rather than designed from scratch. It therefore serves as a model for city planners around the world.

Converted from a former workshop, the ZEB currently houses offices, classrooms and a resource centre. There are also many technologies being tested at the ZEB.

Electricity is generated by the solar panels on the roof and facade of the building, while other technologies allow it to reduce its energy consumption. The net result is that since it was completed in October 2009, the cumulative energy production is larger than the cumulative energy consumption.

Energy production and consumption at the ZEB

This translates to energy savings of about $100,000 a year (depending on prevailing electricity cost), of which about half is due to energy generated from the solar panels, and the remainder is due to reduction in energy consumption.

The cost of retrofitting the building was not cheap, however. The solar energy system alone cost $2 million. Given that it has a typical lifetime of at least 20 years, the energy savings it provides will only pay back half of its cost. However, as the price of solar panels drops with increasing scale of production, while the cost of fossil fuels rises, there will eventually be a point in the future when solar energy becomes cost-effective.

Solar panels on rooftop of ZEB

Solar panels on rooftop of ZEB

Nevertheless, from the visit, it became clear that the cheaper way to go green is not to use the energy in the first place. From the picture above, you can see the red chimneys that help to provide natural ventilation for the multi-purpose hall, thereby dispensing with energy guzzling air-conditioning.

Natural ventilation system

Natural ventilation system

At the same time, we also realised that air-conditioned rooms have a terrible side-effect. While we were at the visitor centre, there was an screen which showed the carbon dioxide concentration in the various rooms. Although we were quite well spaced out, the carbon dioxide concentration had risen to 576 parts per million (ppm), as compared to normal level of about 390ppm! That’s a 50% increase! Although one of our fellow participants, who is a building consultant, said that it is within the “healthy” range, it makes me wonder how that will affect our productivity at work.

Monitoring the vital stats of the building, including carbon dioxide concentration

Monitoring the vital stats of the building, including carbon dioxide concentration

If you want to find out more, visit their website: www.bca.gov.sg/zeb!