Development of Flywheel-Based Resilient Fast charging Platform Project Leader: Hossam Gaber ( Project Coordinator: Yoka Cho ( 1

2 Pain of potential EV/PHEV users Long charging times Limited range (range anxiety); Inability to install chargers at every desired location; Limited number of public charging stations; Insufficient infrastructure

3 Pain of power system Increased peak power demand Network congestion transmission and distribution New sources of disturbances Additional transformer capacity required Additional investment in infrastructure required

FFCS: Flywheel-based Fast Charging System -4- Solution is here

5 Why FFCS?

-6- Higher Power Densities For hybrid vehicle applications, flywheels offer much higher power densities than conventional batteries. High Reliability and Cycle Life Flywheels in particular offer very high reliability and cycle life without degradation. Environmental Footprint The environmental footprint of flywheels can potentially be very small, as flywheels can be built with non-hazardous materials and are easy to recycle. Temperature Sensitivity Flywheels are generally less sensitive to the ambient temperature than batteries. Some important thermal limits are set by the temperature in: the windings, to avoid melting; the magnets, to avoid demagnetization; and the composite material, to avoid burning it.

-7- Fast charge capabilityHigher energy densityLow maintenanceLong life-time FFCS Energy Storage Benefits

Transportation Electrification Implementation Strategies of FFCS -8-

Energy Storage Implementations for Transportation Electrification -9-

-10- Case Study on Electric Buses ■ Long hours each day: up to 20 hours, up to 300 km/day ■ Short charging duration ( “ few minutes “, charging time should be approx. 10% or less of “ driving time “ ) ■ Very high reliability even at bad weather conditions ■ Fast & easy exchangeability of components in case of failures ■ Easy on charging process itself 300 km/day “ few minutes “ charging time FFCS Charging Requirements System Sizing and Technology Plan

-11- For 12m-Bus with Fast Charging ■ Distance between 2 charges: 14 km ■ Average speed: 18 km/h => 47 min. bus driving time for 14 km ■ Energy requirement/charge: 25 – 35 kWh (1.8 – 2.5kWh/km for 12m-Bus) ■ Depth of discharge: about 50% => kWh ■ Charging duration: 5 min. (9.8% of sum of driving + charging time for 14km-cycle) ■ Power of charge: 35 kWh/charge within 5min. => 420kW ■ Lifetime: Up to ~7 years, depending on various factors (depth of (dis-)charge, temperature, etc.) 47 min. bus driving time for 14 km 25 – 35 kWh Charging duration: 5 min. Power of charge: 35 kWh/charge within 5min. FFCS