The GDMS Technologies uses the system frequency as a communication means to achieve instant 100% national coverage of all electrically connected devices of demand side loads and generation using an existing infrastructure. The system enables direct, instantaneous aggregate power consumption/generation measurements to be performed by the System Operator from the control room.

The GDMS system consists of a transmitter network made up of a number of load devices (resistive heating elements) whose power consumption is modulated in a desired pattern (i.e. a “code”). This pattern is then turned into minute (imperceptible at an operations level) changes of the grid frequency (modulation), and this modulation is subsequently decoded by the other part of the GDMS system – the receiver devices. These are installed onto domestic loads (e.g. hot water immersion heaters) and receive the transmitted codes from anywhere in the grid, and act accordingly.

The system will be operated remotely to enable greater visibility of available capacity and provide finer control for National Grid’s control room to utilise demand side resources in system balancing (response and reserve). The system will also be a highly useful grid inertia analysis tool for National Grid and Network Licensees to provide unique visibility of grid inertia right into the distribution networks. As an operating system, by spreading the transmitted codes National Grid can ensure reliable and resilient broadcast communications and through the use of trusted encryption techniques and anonymised load groups, The system represents a highly secure communications and innovative aggregated measurement channel.

Benefits

The success of the project will be based on the following outputs;

• A primary report demonstrating the identification and mitigation of risks

• A secondary report cataloging the installation of transmitters/receivers and testing.

• A concluding report to define the aggregated power measurement the test results, findings and conclusions.