NOVELTY - The pumped storage hydroelectric system, which operates as a closed fluid system using fluid other than water, has high level flexible bladder tank (1) and low level flexible bladder tank (2). The system also has transportable containerized housings or modules for housing a pump, a turbine and control equipment.    USE - Pumped storage hydroelectric system for intermittent energy generation assets, such as onshore wind turbines.    ADVANTAGE - The bladder tanks are connected using lightweight polyethylene or glass fiber-reinforced plastic pipelines to reduce capital and installation costs. The use of bladder tanks, lightweight interconnection pipework and transportable power modules allows for wide scale deployment of the system to locations and at smaller scales not previously viable due to geography, cost, and environmental impact issues. Increases stored energy of the system by installing additional bladder tanks in series. Amount of stored energy can be tailored and scaled up or down by increasing or decreasing number of tanks used. The system operates as a closed loop system to prevent evaporation and fluid loss and allow fluid to be treated and filtered to maintain its quality and prevent system efficiency losses usually due to bacterial growth and contamination. Allows for deployment of the system along the side generation asset to further reduce system cost by sharing electrical interconnection to the main distribution grid network and local infrastructure such as service roads. The flexible nature of the system provides installation benefits, such as allowing the system to be designed around the landscape and not being forced upon it, utilizing use of even poor quality land, and causing minimal landscaping and environmental damage during installation or decommissioning. The system can use working fluid such as brine which lowers freezing point of solution to alleviate need for frost protection. The fluid can be dosed with anti-freeze to prevent fluid freezing problems. Ultraviolet radiation damage to the tanks is prevented by fitting covers for blocking ultraviolet rays. Battery-backed solar photovoltaic system may be used to increase system efficiency by supplying parasitic power requirements of power modules. Provides back-up power in event of loss to electricity supply to critical power users such as data centers, hospitals and manufacturing processes.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of a hydroelectric system.    High level flexible bladder tank (1)    Low level flexible bladder tank (2)    Power module (3)    Pipeline (4)