A facility for generating electricity, including a water source and a plurality of penstocks adapted for selective flow communication with the water source for delivering water from the water source to a turbine electricity generator. An electricity distribution system is provided having a first component adapted to deliver electricity generated by the turbine electricity generator to an electric grid and an alternative second component adapted to use the electricity to power an air compressor. A compressed air storage reservoir is provided for storing air compressed by the air compressor, including an outlet for selectively delivering the compressed air to the plurality of penstocks according to a predetermined sequence for providing energy to the water contained in the penstock to propel the water from the penstock to the turbine.