Electrical power system and method for operating an electrical power system

A method for operating an electrical power system having a plurality of power plants connected to a power grid, the method comprising:

• connecting a central repository comprising one or more electrical energy storage devices directly to the power grid, the central repository being operable to draw power from and discharging power to the power grid, the central repository being configured to be coupled to the power plants via the power grid,
• routing a portion of a power output produced by one or more of the power plants for storage at the central repository via the power grid, during a first period,
• receiving a power demand notification from an individual power plant of the electrical power system during a second period,
• responsive to the notification, operating the central repository to discharge power as a function of said power demand, and making it available to the individual power plant via the power grid during the second period, the second period being shifted in time from the first period.