Zero-Energy Buildings-A Review

A zero-energy building (ZEB), which is an autonomous building energy option, is defined as a building that produces as much energy as it uses from renewable energy sources at the site. Zero-energy buildings can exchange energy with the power grid as long as the net energy balance is zero on an annual basis.In terms of the thermal energy transfer and storage, zero-energy buildings can achieve annual energy consumption levels down to 0 kWh per square metre through the use of renewable energy sources, which compares favourably with the passive house energy criteria per square metre. Energy plus houses, in contrast with both the passive houses and zero-energy buildings, focus on producing more energy per year than they consume, which can lead to an annual energy performance of -25 kWh per square metre. Zero-energy buildings should have features like: i) Enable building owners to be isolated from fluctuating energy prices through the on or off-grid renewable energy supply ii) Help reduce peak electrical demand by self-supplying energy demands on site iii) Go hand in hand with the transformation of energy infrastructure and market. Zero-energy buildings can be achieved by incorporating energy efficiency measures and on-site renewable energy generation technologies and its energy efficiency measures include: creating a high-performance building envelope, installing energy efficient appliances and lights, increasing the use of passive solar cooling and heating techniques and installing high-efficiency mechanical systems that match the lower energy requirements of the home. On-site renewable energy generation systems can be available within a building’s footprint by using PVs, solar hot water and wind located on the building or at the site by means of PVs, solar hot water, low impact hydro and wind located on-site not on the building. Zero-energy building is still in the conceptual stage in the Asia-Pacific region. A few pilot projects have been applied to public buildings, such as research institutes, for demonstration purpose e.g., Sustainable Energy Technology Centre in China, Pusat Tenaga Malaysia’s Zero Energy Office (ZEO) Building and National Institution of Environmental Research in Republic of Korea.