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Guiding the Selection & Application of Wayside Energy Storage Technologies for Rail Transit and Electric Utilities Transit Cooperative Research Program Transportation Research Board Page 51 of 61 Appendix B - Vendor Advisory Group In the same way that the APTA Energy Storage Research Consortium unified the transit agencies and government members approach to energy storage, creation of the Vendor Advisory Group has organized the energy storage vendors seeking to do business in this area. The vendors joining the Vendor Advisory Group are shown in the following table, which also shows their primary product. Flywheel Battery Electro-Chemical Capacitor Hybrid Battery and EC-Capacitor Ultralife Pentadyne Impulse/Envitech Maxwell Qynergy Vycon Sojitz (Toyo Denki) EPX Saft Batteries Ioxus The purpose of the Vendor Advisory Group was to give neutral technical information on energy storage technologies appropriate for rail to the Study Team for reference while doing the simulations. Early in the process the study group turned to the industry to provide technical insight into energy storage devices, provide a confirmation of assumptions used in modeling, offer order of magnitude estimates for device costs, and general support to guide the study. Information from the vendors was solicited using a questionnaire as shown below. The study team was interested in categorizing product variability and operating ranges so that appropriate assumptions could be made within the model simulation studies and that the study group could best envision future technological innovations. The questionnaire addressed units of 1.5 MW and 3 MW storage capacities. From some of this data, for example, a 1500 KW battery unit required between 8 and 112 battery cells, and power densities ranged from a value of 0.12 kW/ft3 to 7.5 kW/ft3 . For all the systems considered, the number of lifetime cycles ranged from 5,000 to 10,000,000. The Vendor data received in response to the questionnaire such as the example shown below was very helpful to the Study Team. ⢠It gave the team confidence that the charging and discharging control algorithms we have used reflects the actual function of the devices ⢠It gave the team confidence that the input parameters we have used for the energy storage simulation models are appropriate ⢠It helped the team decide what types of devices can meet the required power ratings and energy capacities for different systems
Guiding the Selection & Application of Wayside Energy Storage Technologies for Rail Transit and Electric Utilities Transit Cooperative Research Program Transportation Research Board Page 52 of 61 ⢠It helped the team decide what types of devices can meet the required life cycles for charging and discharging in different systems To provide the vendor community with some level of knowledge regarding the power and cycling needs their devices may need to support, the study team performed simulations of generic system designs incorporating energy storage devices and developed a generic load demand profile as seen in Figure B-1. From this information, vendors were able to gauge the potential match of their device characteristics with the demand profile of an average system. Category Data Type Value (Based on Current Technology) Value (Based on Technology 5 years from Now) Electrical Number of units/cells required Energy Storage Capacity (kWh) Charge efficiency (%) Discharge Efficiency(%) Standing Loss (kW) Charging Current Limit (Amps) Discharging Current Limit (Amps) Power Density (kW/cube_feet) Energy Density (kWh/cube_feet) Life cycle Minimum Cycle Time for Charge/Discharge (minutes) Lifetime Charge/Discharge Cycles (number of cycles) Useful Lifetime (years) Degradation over Time, % Sample Questionnaire on A 3000 kW Unit (750V DC) Environmental Working Temp Range, deg F Any Special Environmental Requirements (Air conditioning, humidity, vacuum, etc) Does the unit require external power (415V AC) Device dimensions (LxWxH in feet) Footprint (LxW in feet) Any special requirement for disposal of retired/replaced units Application Voltage support Peak Shaving Energy Savings
Guiding the Selection & Application of Wayside Energy Storage Technologies for Rail Transit and Electric Utilities Transit Cooperative Research Program Transportation Research Board Page 53 of 61 Simulated ESD Load Cycle (8-Car Train, 2 Minute Headway, 3MW ESD) -3,500 -3,000 -2,500 -2,000 -1,500 -1,000 -500 0 500 1,000 1,500 2,000 2,500 3,000 3,500 7:30 AM 7:31 AM 7:32 AM 7:33 AM 7:34 AM 7:35 AM 7:36 AM 7:37 AM 7:38 AM 7:39 AM 7:40 AM 7:41 AM 7:42 AM 7:43 AM 7:44 AM 7:45 AM Time Po w er (k W ) -2,500 -2,250 -2,000 -1,750 -1,500 -1,250 -1,000 -750 -500 -250 0 250 500 750 1,000 Vo lta ge (V ) Power (kW) Voltage (v) Figure B-1: Simulated Generic ESD Load Cycle
