Design of Charging Infrastructure for Electric Buses

This article explores the factors involved in creating charging infrastructure for electric buses – Site Engineering, Power Infrastructure, Design of Charging Solution, IT Systems and Business Model

Electric Bus Ecosystem in India

The electric bus ecosystem in India looks poised to take off.

According to SMEV report, 600 electric buses were sold in India in FY19-20, up from 400 in FY 18-19. Overall, FAME II provisioned allocation of demand incentives worth INR 3,545 crores i.e. 35% of total scheme outlay, for the adoption of 7,090 e-buses over three year period between 2019-20 and 2021-22.  These buses need to satisfy notified localization level and technical specifications to be eligible for the incentives.

The number of electric buses in India’s public transport system is expected to see a surge in coming years owing to DHI’s sanctioning of 5,095 e-buses for intra-city operations in 64 cities through respective State/City Transport Authorities, along with 400 e-buses for intercity operations and 100 for last-mile connectivity to Delhi Metro Rail Corporation. (A city-wise breakdown of allocated e-buses can be seen in the official document by DHI.)

The sanction was made in Sep 2019, following which multiple transport authorities started the procurement process for commissioning the electric buses on an operational cost model. (You can visit this link for a complete list of CTUs/STUs that have issued RFPs for procurement of e-buses under FAME II.)

As procurement and commissioning continue, we can expect to see an increasing number of electric buses plying on Indian roads in the next couple of years. 

Charging Infrastructure for Electric Buses

A major part of readying the ecosystem for e-buses involves setting up of adequate and efficient bus charging infrastructure.

The dynamics of Charging infrastructure for electric buses differ from other vehicle segments like electric 2W, 3W and cars. There are two major parts of charging infrastructure: Charging Solution and Power Infrastructure.

Nuances of Charging Solution for electric buses

– Complete reliance on commercial charging: Unlike other vehicle segments, there is no ‘Home Charging’ for electric buses.

– Larger battery capacities (100 kWh, 200 kWh or more) than other vehicle segments.

– Higher Charger output ratings from 120kW to 300 kW

– Charging management software for load balancing, grid communication, demand management and monitoring of operations

– The charging equipment for e-bus charging entails higher capital expenditure than other vehicle segments.

Power Infrastructure for e-bus charging hubs

Transport corporations provide the space at bus stands/depots for setting up the charging hubs. Power Infrastructure for the charging station requires extensive site planning and coordination with DISCOMs to achieve an optimal charging setup, taking into account multiple factors including:

– High load requirements typically in the range of 2 MW to 5 MW

– HT (High Tension) electricity connection, additional safety measures, control systems, and installation of ancillary infrastructure

– Space availability at the bus depot, required number of charging points and vehicle placement

– Assessment of current grid connection and required load capacity. Required load capacity depends on the maximum number of buses that need to be charged simultaneously and power output of deployed EVSEs.

– Running schedule of the buses to formulate a suitable charging schedule

Today energy is being supplied from ‘Grid-to-Vehicle’ but as EVs numbers rise, these can also be used as a Temporary Distributed Source of Power by using ‘Vehicle-to-Grid’ energy flow to augment the Grid wherever needed. 

Also Read: Preparing Power Distribution Network for EV Charging Needs

Alongside site engineering and charging solution design, information technology is a key focus area for bus charging infrastructure. IT solutions for the charging hubs encompass systems for charging operations management and monitoring, grid communication, energy management, fleet management and data analytics. Off-board data generated at the charging points can offer valuable insights into parameters such as energy consumption, efficiency, battery health and usage patterns.

Business Model for e-bus Charging Stations

An operational cost model is preferred for setting up and operating bus charging infrastructure, wherein Charging Network provider makes the capital investment and runs the charging hubs on behalf of Bus OEMs (that have been awarded the bus-commissioning contracts by transport authorities). This removes the upfront cost of charging equipment and installation for the OEM, and helps the OEMs focus on operating and maintaining the buses.

CHARGE+ZONE is a Vadodara based start-up that develops cost-efficient, smart charging hubs for buses. The company recently finalised a tie-up with a major European utility firm. Speaking to EVreporter, Kartikey Hariyani, CEO of CHARGE+ZONE expressed a bullish outlook towards India’s electric bus ecosystem. “We have already deployed fast DC charging hubs for electric buses in Ahmedabad and Mumbai for inter-city and intra-city operations respectively, and plan to install 1000+ charging points for e-buses in the next 3 years”, says Kartikey. The company has also partnered with Microsoft to build capabilities in cloud computing and data processing.

China already has more than 4,20,000 electric buses on the road, making up for nearly 14% of its total bus fleet. In India, STUs run more than 1.5 lakh buses all over the country. Electrification of our bus transport holds tremendous potential for cleaning up the environment and helping the STUs achieve much needed operational efficiency.

Battery Swapping presents an alternative fuelling solution for electric buses and organisations like Sun Mobility and Ashok Leyland have been actively pursing it. Swapping for electric buses will be covered in detail in a subsequent article.

Suggested Reading: Charging India’s Bus Transport – 2019 by AEEE and Shakti Foundation