[en] Work is reported on the development of two superconducting magnetic energy storage units. One is a 30-MJ unit for use by the Bonneville Power Administration to stabilize power oscillations on their Pacific AC Intertie, and the second is a 1- to 10-GWh unit for use as a diurnal load-leveling device. Emphasis has been placed on the stabilizing system. The engineering specification design of the 30-MJ superconducting coil was completed and a contract will be placed for the coil fabrication design. Bids have been received for the stabilizing system 10-MW converter and coil protective dump resistor. These components will be purchased in 1979. The reference design for the 1- to 10-GWh diurnal load-leveling unit has been totally revised and is being assembled in redrafted report form. Plans are to build a 10- to 30-MWh prototype diurnal load-leveling demonstration unit