The Integration of Renewable Energy Supply with the Electricity Demand from Inductively Charged City Buses

Abstract

The possibility to integrate renewable energy supply with the electricity demand of inductively charged city buses is investigated in this paper. Rising CO2 levels due to transport put a strain on the environment in urban areas. One method to attend to this problem is by electrifying city buses. City buses with an electric motor do not exhaust CO2 and other greenhouse gases. To make the use of electrified buses sustainable though, the source of the electricity should be a clean source, without CO2 or greenhouse gas emissions. However, the sources of clean renewable energy, solar PV and on- and offshore wind, are intermittent. Their variable production scheme can pose problems for charging and storage. For that reason, inductive charging is introduced. It is a new method to charge a vehicle contactless, by making use of electromagnetism. The aim of this research is to see whether supply and demand can be integrated, as to make sure there is minimal need of storage. Both daily renewable energy supply patterns from solar PV, on- and offshore wind and the electricity demand from city buses in four medium-sized cities is reviewed. To determine the renewable energy supply patterns, wind speeds and solar irradiation data are obtained from the database of the Royal Dutch Meteorological Institute (KNMI). These input values are used for the current and the future production scenarios. To define the electricity demand from the buses, four medium-sized cities were chosen and their bus activity was analysed. The amount of kilometres driven per hour resulted in the activity for the entire city. Combined with the energy use per kilometre, the total hourly electricity demand was calculated. A smart grid can be utilized to supply the generated electricity at the place where it is necessary. This study finds that for all seasons, the average curves for supply and demand match. This means that inductive charging could be a solution to drive an electric motor, without needing a large storage capacity, to diminish CO2 exhaust in urban areas.