Purpose of MetroHESS research project is to develop a Hybrid Energy Storage System (HESS) in order to exploit the energy from regenerative braking of Athens metro rail systems. The recovered energy being stored in the HESS will be used to cover base loads such as Lighting Systems and Passenger Transport Systems, which are main energy consumers for the metro operator.

For the architecture of the Hybrid Energy Storage System, measurements of the regenerative braking energy potential in traction rectifier substations and in the traction systems on board of trains along with the energy auditing of selected metro stations will be conducted.

The results of the measurements will serve as input for the dimensioning process.

The combination of energy storage components with different electrical characteristics will be tested and appropriate energy management strategies will be also exploited. The developed system will be evaluated for its functionality and financial viability.

Ultimate goal of MetroHESS project is the largest scale of application of the Hybrid Energy Storage System in the transport sector.