2.8.2 Integration of Renewables In The Built Environment

year. Not only the wind speed is not high enough to generate wind power effectively, but

also, the direction of the wind changes throughout the year, making it hard to have

stability.

Biomass

Singapore’s neighbouring countries, Malaysia and Indonesia combined account for 80% of world’s palm oil supply [2]. Singapore’s location allows them to have easy access to import biofuels from these neighbouring countries. However, this is not considered as

generating the alternative energy of their own. Although Singapore is in the same climate

zone, they do not own vast amount of land that serves as bioenergy resources, thus it is

hard for Singapore to generate bioenergy.

2.8.2 Integration of Renewables In The Built Environment

Looking at a smaller scale, there are more restrains in generating effective amount of

renewable energy in the built environment, especially densely populated and urbanised

cities like Singapore. Nevertheless, Singapore’s tropical climate allows high amount of

reliable solar radiation to be available. Thus using solar power would be ideal in

Singapore. There are mainly two types of technologies for retrieving energy directly from

the sun: solar thermal and photovoltaics.

Solar Thermal

Solar thermal energy is the energy from the sun that is absorbed by solar thermal

collectors. The solar collectors can be air or water based, and they are in forms of flat

plates or evacuated tubes [4]. For domestic hot water heating (DHWS) systems, there are

passive and active systems. Passive systems use gravity and the tendency for water to

naturally circulate as it is heated through the system without a pump. They are generally

more reliable and easy to maintain. Active systems use electric pumps, valves, and

controllers to circulate water or other heat-transfer fluids through the collectors [5].

Other types of solar thermal system include concentrating high temperature collectors,

such as parabolic troughs, dish system, and central-receiver systems.

There are three main ways that hot water from solar thermal collectors could be used -

space heating, hot water supply and provide heat for absorption refrigeration system.