Comparison of subway energy storage methods

How much energy does New York City subway use?

In 2021, the New York City Transit Subway system consumed approximately 1,500 GWh of traction energy with a demand of about 3,500 megawatts (MW), costing around $203M. Subway trains introduced in the past 20 years have included the capability to perform regenerative braking. All new subway car procurements require regenerative braking capability.

Can wayside energy storage systems improve regenerative braking energy?

Maximum Regenerative Energy Improvement on R142 Train City University of New York (CUNY)/ConEd/NYCT performed a study pertaining to the application of wayside energy storage systems (ESS) for the recuperation of regenerative braking energy within the NYCT subway system.

How is energy storage used in energy recovery applications?

In energy recovery applications, energy storage is used to reduce energy consumption through the capture and release of regenerated energy from rolling stock. Typically, energy produced by the train during braking is consumed by other trains operating in the vicinity.

How much does ESS cost per substation?

Twenty-five percent (25%) demand reduction would result in $166,140 annual savings per substation. The maximum ESS cost to realize a 10-year ROI would be approximately $1,661,400 per substation (based on current demand power rate). Avoided Generation Capacity Costs (AGCC).

What percentage of braking energy is dissipated through onboard resisters?

Twenty-three percent (23%) of the available braking energy is dissipated through the onboard resisters. This energy is potentially available for recovery using ESS or other energy saving techniques (assumes train can return all available energy via regenerative braking).

How many MWh of storage will a 78th Street substation have?

a total of 26 MWh of storage recharged overnight. Control would be based on power draw at each individual substation. Figure 11. Power Demand at the Roosevelt Avenue and 78th Street Substation During a Weekday Figure 11 shows demand at the Roosevelt Avenue and 78th St. substation, one of 13 substations serving the 7 Line.