Technical & economic evaluation of district cooling system as low carbon alternative in Kuala Lumpur City

Abstract

Kuala Lumpur (KL) city which has started its initiatives to become one of the low carbon cities in Malaysia, has the potential of implementing District Cooling System (DCS) in its existing energy system. Nowadays, most office buildings in Malaysia are utilising the conventional air-conditioning at each individual premise for space cooling purpose. In the development into a low carbon city, DCS could replace the conventional air-conditioners as it is more energy-efficient and subsequently reduces carbon emission to the environment. This study aims to compare and evaluate on four different cooling systems that are suitable to be implemented in KL city. A case study is created where a cooling load of 250,000 kWh/month of five office buildings in the same vicinity in KL city is to be met. Three parameters are studied to evaluate the cooling systems, namely energy consumption, costing and carbon emission, on a yearly basis. The result shows that centralised DCS is expensive in term of its initial investment and operational costs compared to individual air-conditioner. However, the type of energy source in DCS is an important factor to determine the total energy consumption and carbon emission of the cooling system. DCS that combines biogas-fired steam boiler and absorption chiller is the best option to be implemented. The system can generate own electricity to be used on-site, while the use of biogas effectively can achieve a carbon-neutral electricity production.