A Study of Wayside Energy Storage Systems (WESS) for Railway Electrification

Results of a 1982 study of wayside energy storage systems (WESS) for railway electrification are summarized. The study was performed by SNC Inc. for the Transportation Development Center of Transport Canada (TDC). WESS introduces savings in the overall costs of the electric energy supplied to the catenary, by reducing the peak load seen by the utility and, if locomotive regeneration is available, the total energy demand. A number of energy storage systems were evaluated for near-term WESS applications. Two were found to be practicable: lead-acid batteries and steel flywheels. The required battery technology already exists and installations, existing or planned, approach the required levels of stored energy and power. For steel flywheels existing systems have available stored energy levels of less than one thirtieth of that required for WESS. Detailed engineering studies would be necessary to demonstrate that single wheel systems of the capacity required could be manufactured at reasonable cost. Budget estimates were derived for the combined installation and operating costs of battery and flywheel WESS. These were compared with the potential savings in the costs of electricity supply for a 20-year operating life, using average Canadian Utility rates and typical WESS parameters.