Abstract: A building comprises a network of energy storage and energy consuming assets, which is connected to an alternating current electric supply grid having a normal frequency through an energy management system linked to a server. The energy management system measures over a period of time the energy consumption against time of the energy consuming assets and stores the measurements taken and measures over a period of time the energy stored against time in the energy storing assets and stores the measurements taken. The measurements of energy consumption and energy stored are used to derive the base net energy need in particular time periods. The net energy need in individual time periods is exported to one or more third parties.

Abstract: A method of managing energy in an energy consuming and storage system includes the step of measuring the frequency or voltage of the electricity supply over a period and permitting excess energy to be stored in one or more assets in the system when the frequency or voltage of the supply exceeds a pre-set maximum or ceasing taking energy from the supply when the frequency or voltage of the supply falls below a pre-set minimum.