City-scale assessment of stationary energy storage supporting end-station fast charging for different bus-fleet electrification levels

Abstract

Fast-charging electric buses at bus end-stations can lead to high peak-demand charges for bus operators. A promising method to reduce these peak-demand charges is combining the fast charging station (FCS) with a stationary energy storage unit (SES). This work analyses the potential cost reduction for installing optimally-sized SES at bus FCS on a city scale for different levels of bus-line electrification. Results show that the cost-reduction potential reduces with increasing levels of bus-line electrification. For a case study based on the Singapore bus network, installing an SES at FCS can reduce the total costs by 1.8% on average when 30% of the bus lines are electrified, while the average cost reduction in a fully electrified bus network is 0.4%. A comparison of the results with previous studies showed that the cost reduction potential is highly sensitive to the peak demand pricing method.

Publication
Journal of Energy Storage

Selected figures

Methodology flowchart

methodology_flowchart

Map of Singapore with the location of fast-charging stations at bus termini and their respective number of chargers for each electrification scenario

charger_count_map

Power curves for one terminal

power_curves

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