Benefit Evaluation of Electric Bus

近年來國際原油價格上升，衝擊每個國家的整體能源消費，尤其全球運輸部門所消耗的能源佔了世界各國能源消費結構係僅次於工業部門，而大部分國家運輸部門所消耗的能源所佔比率均超過20%。因此，如何發展更有效率的公共運輸系統，以減少運輸部門的能源消耗與溫室氣體排放，實為一項重要課題。我國在市區公車以及國道客運車輛之中，至今仍舊以柴油公車為主流，隨著科技發展，目前市面上有諸多替代車種，如純電動公車(Electric Bus)、油電混合電動公車(Hybrid Electric Bus)、天然氣公車(Natural Gas Bus)、燃料電池公車(Fuel Cell Bus)等。上述不同類型的公車不僅可以減少空氣汙染，部分車種亦可減少噪音汙染提升環境品質，並使得能源效率提升。 目前諸多國家逐步提倡採用低汙染車輛取代傳統柴油公車，這些多樣化的新能源公車系統有何差異，以及其生命周期成本為如何，實為重要之研究課題。本研究係利用分析性模式(Analytic Model)以及生命週期成本之概念，探討「柴油低地板公車」、「油電混合低地板公車」與「換電式電動低地板公車」等三種不同動力系統的公車，在營運成本上的差異分析，以提供給業者及決策者在公共運輸能源政策之參考。透過本研究建立之模式與情境分析探討之結果，換電式電動公車成本之電池與換電站成本由政府補助或由第三方業者負擔之前提下，柴油公車與油電混合公車之外部成本提高，電動公車總成本為最低，未來推動電動公車將具有相對的優勢。因此，為了改善交通環境與服務品質，在節能環保的思維下，具有零排放特性的電動公車勢將成為未來公共運輸的發展趨勢，然經由本研究之觀察發展，初期仍有賴政府在考量外部效益基礎下，提供購車、換電站設施以及營運上之補助。Due to the raising of crude oil prices and green house effect, how to reduce energy consumption and green house emissions is an obvious objective for every country around the world. Generally, the transportation sector is the second large energy-consuming sector right below the consumption of industrial sector. As a result, how to develop more efficient public transport systems, and reduce energy consumption and greenhouse gas emissions in the transport sector is important. In bus services, the conventional diesel buses are still the mainstream in Taiwan while the emission has been defined as that of coursing tumors. With the development of science and technology, there are many new energy vehicles such as electric bus, hybrid electric bus, natural gas bus, fuel cell bus, and so on in the world. These buses can not only reduce air pollutions, but will also lower the noise level. Consequently, they can improve environmental quality. In order to reduce the emissions and lower the degree of crude oil dependence, electric bus has become the mainstream in public transportation in the near future. Since there is not a clear comparative analysis in Taiwan, this study aims to develop a mathematical model based on using the concept of life cycle cost to analyze the differences in operating costs of the diesel bus, the hybrid electric bus, and the electric bus in a hypothetical environment. Moreover, numerical examples and sensitive analysis are also conducted to verify applicability of the models. The results of this study have shown that electric bus has significant benefits in terms of external costs. It is also shown that electric bus will have comparative advantage on conditions that government provides subsidies and imposes air pollution tax with consideration of its external benefit and energy savings