A Decision-Analytic Study of Transport Fuel Alternative for Singapore

Lee Ian Wurn

Abstract

With the depletion of available supplies of oil world-wide, it has become increasingly urgent for countries to develop new technologies to better use the limited supplies of oil or to change altogether to another alternate source of energy.

The objective of this project is to formulate a framework of a decision-analytic study which can be applied to Singapore for the purpose of evaluating a suitable fuel alternative for land transport vehicles for the Year X. The Year X is defined as a year between 2020 and 2030. A previous study conducted on this similar topic has yielded that the top three fuel alternatives to use are electricity, natural gas and oil, which signifies no change from the current choice of fuel. In this project, we have analysed in detail the potential of these three fuel alternatives. In the course of the project, the viewpoint of policy makers have also been adopted.

The previous study was performed using the Analytic Hierarchy Process (AHP), which is commonly used due to its simplicity. In this project, we would like to give considerations to more factors and hence, the Influence Diagram (ID) technique has been selected to assist in analysing the problem. An Influence Diagram can clearly map out the relationships between the innumerable factors that we would have. That is one of the advantages of using the ID technique. However, the ID technique also introduces a lot of complexities into the problem, the biggest of which is the need to determine probabilities for any factor brought into consideration. This proves to be a cumbersome and time consuming process, but we feel that the results at the end would justify its use.

The results from the ID technique is then further analysed using sensitivity analyses. This is done for two reasons. The first is that we need to know that a slight change or some uncertainty in a factor will not lead to another optimum fuel alternative. If it does, we will have to ensure that the information regarding that particular factor is determined properly. The second reason for sensitivity analyses is to allow us to know how much of a change and in what factors we need to change in before we can have a targeted fuel alternative as the choice alternative.

The results tells us that natural gas is the fuel alternative of choice in the Year X for Singapore. The sensitivity analyses tells us that this decision is stable provided that we do not shift development of natural gas as a fuel alternative to another emphasis, like for example, concentrate on development of electricity as a fuel alternative. Barring all that, natural gas will be the best transport fuel alternative.

The feasibility of applying this decision-analytic study framework on other countries have also been explored and the results are promising. A set of weights and factors have also been derived to allow users to have some quick start figures to use in the evaluation of a country without going through the hassle of evaluating every single factor there is.