Improving the energy efficiency of high speed rail and life cycle comparison with other modes of transport

Abstract

The world energy crisis and global warming call for a reduction of energy consumption. High speed rail, increasingly viewed as an effective solution to inter-city passenger transportation challenge of the 21st century, has the significant ability of increasing passenger capacity and reducing journey time. The advent of high speed rail provided many research opportunities. So far studies have been contributed from different perspectives: economical, environmental, and technical. The main research gaps are: addressing the problem of the effects of route geometry on train energy consumption and quantifying the contributing factors towards differences in energy consumption between different types of high speed trains. In addition, this energy assessment cannot be based solely on the energy consumption in the operation phase. In the life cycle assessment of the whole railway system, the vehicle evaluation is relatively straightforward, but the infrastructure raises many difficult issues. In this thesis, an existing approach for modelling the traction energy of electric trains is developed and extended to simulate the train operation under different driving strategies. Baseline simulation is carried out to estimate the journey time and energy consumption of a High Speed 2(HS2) reference train running on the London-Birmingham proposed high speed route. The influence of route geometry and train configuration on energy consumption is investigated, based on the metric of energy consumption per passenger kilometre. Simulations are also carried out of different types of high speed rolling stock running on the proposed HS2 route, to identify the key areas of vehicle design which help to minimise the energy consumption of high speed rail travel. The life cycle assessment of railway infrastructure is carried out in four stages of a whole life cycle: production, operation, maintenance and disposal, the influence of route parameters on life cycle cost is also investigated. Finally, high speed rail is compared with competing modes of transport, i.e. the aircraft, the automobile and the conventional train, in both operational energy efficiency and whole life cycle analysis. The high speed rail transportation has great advantage over the road and air transport, giving a reduction of carbon emission by roughly 95%, among which the operation stage contributes the largest reduction.