1 1 1 0

Electric Transportation Energy Supply Systems

01 September 2020, by Prof. Christine Schwaegerl SC C6 Chair (DE), Prof. Geza Joos SC C6 Secretary (Canada)

Electric Transportation Energy Supply Systems        Electric Transportation Energy Supply Systems

Prof. Christine  Schwaegerl SC C6 Chair (DE), Prof. Geza Joos SC C6 Secretary (Canada)


Transportation systems are among the largest consumers of fossil fuels, after electric power generation, in many jurisdictions. These systems include passenger vehicles, busses and urban light rail systems, trucks for local delivery and long-distance transport of merchandise, and diesel-powered railway systems. Transportation electrification is therefore one of the important approaches to achieve decarbonization of the economy, and reduction of greenhouse gas emissions, and to reduce the global consumption and reliance on fossil fuels.


On-board electricity for transportation electrification can be provided in several ways, including battery energy storage systems, hydrogen fuel cells, and electrochemical supercapacitors. Other options considered are flywheel and compressed air energy storage systems. Electrochemical batteries are today the more common solution for transportation electrification, particularly for passenger vehicles, and to a lesser extent, city busses. Hydrogen fuel cells have also been developed and prototypes have been installed and are in operation since the 1980s in passenger vehicles and busses. Several technical and economic issues are being currently investigated, including the cost and life of the fuel cell and the required hydrogen distribution infrastructure.

One of the issues common to all on-board energy storage systems is the need to recharge them, in the case of batteries and supercapacitors, or refuel them, as in the case of fuel cells. This requires the deployment of an appropriate infrastructure. These infrastructures differ significantly in their impact on the overall energy system from which they are supplied: the electric recharging stations are connected to the existing electric distribution system, and can therefore impact distribution grids negatively or help the operation of the grid; in the case of hydrogen recharging stations, a hydrogen infrastructure needs to be deployed, the hydrogen being produced and distributed using dedicated installations. 

The recharging infrastructure can be associated with and exploit renewable energy resources, such as wind and solar power generators. In the case of electric vehicle batteries, the charging stations can be fed directly from these generators. In the case of hydrogen, it can be produced using these generators by electrolysis. 

A new SC C6 working group will be set up to address the general problem of on-board power generation, with a focus on the more common electric transportation energy supply systems, namely batteries and fuel cells. It will provide a comprehensive assessment and comparative evaluation of the available technologies from the key aspects related to a successful deployment, including technical, economic and environmental considerations.


The scope of the working group is the study of the available electric transportation energy supply systems from perspective related to the relative costs of the equipment, which include capital and operating costs, volume, weight and installation requirements, reliability, availability and maintainability considerations, and the recharging infrastructure deployment considerations. The energy supply systems include batteries, hydrogen fuel cells, electrochemical supercapacitors, flywheel and compressed air systems. Environmental impact, life expectancy and life cycle considerations will be covered. The following topics will be addressed. Details of propulsion systems are not covered.

1.    Review of electric propulsion systems state-of-the art and requirements – Electric transportation modes and systems: electric vehicles, light rail, busses and trucks – Electric propulsion supply system requirement: power, energy, range, performance (short term overload), volume and weight, operating environment, efficiency, relative cost and business case – On-board energy storage system options for electric propulsion systems: batteries, electrochemical supercapacitors, flywheels, hydrogen fuel cells, hybrid systems – General recharging infrastructures.

2.    Comparative evaluation of on-board energy supply systems – Power and energy considerations, range and losses, operating temperatures and environment, safety, security and risk mitigation – Recharging frequency and duration – Relative  capital costs, weight, volume, and thermal efficiency – Installation considerations – Operating costs – Reliability, availability and maintainability – Life expectancy – Life cycle assessment, material use and environmental impact, and repurposing and recycling – Specific considerations for on-board energy storage (batteries, capacitors, flywheels): charging and discharging rates and lifetime cycles, idling losses – Technology  readiness and expected developments, standardization. 

3.    Comparative evaluation of recharging infrastructure – Requirements: size, capacity, location – Design and implementation – Reuse of existing infrastructure – Impact on the existing infrastructures (electric power grid, energy supply infrastructures) – Environmental impact and mitigation.

4.    Regulatory and legal framework – General considerations and constraints.   

5.    Business cases for electric propulsion selection and deployment: tools, use cases, stakeholders (single, multiple), implementation considerations – Experiences and case studies, regional considerations, ownership and maintenance.

6.    Guidelines and best practices – Technology deployment, business case and economic considerations, environmental and regulatory considerations.


The list of expected benefits from the proposed work includes:

  1. Commercial, business, social and economic benefits for industry or the community
  2. Existing or future high interest in the work from a wide range of stakeholders
  3. Contributions to new or revised industry standards
  4. State-of-the-art or innovative solutions or identification of new technical directions
  5. Development of a guide or survey related to existing techniques, or an update on past work or previous Technical Brochures
  6. Contributions to improved safety utilization
  7. Contributions to environmental requirements and the UN sustainable development goals.


Worldwide experiences are welcome to contribute to the success of this WG. Please let us know if you are interested in becoming a member for this group.

Welcome to the world of CIGRE

Welcome to the world of CIGRE


Welcome to the world of CIGRE



Solve all power system challenges in one unique place

To find the solutions you need in one unique place, join CIGRE. As the preeminent global technical organisation, CIGRE is uniquely positioned to offer the full spectrum of low through high voltage perspectives, industry colleagues and end to end knowledge.