We will approach potential service providers directly if a specific requirement is identified. Intertrip services are required as an automatic control arrangement where generation may be reduced or disconnected following a system fault event.

For the system to generator operational intertripping schemes, section 4 (Balancing Services) of the Connection and Use of System Code (CUSC) specifies the commercial arrangements for the arming and operation, and describes the mechanism for the administration of associated payments.

The payment terms for the commercial intertrip service are determined bilaterally between us and the generator.

Payments are made up of:

Arming payment (£/settlement period) – paid for each settlement period where the generator (at National Grid’s request) allows signals to pass from the intertripping scheme to the relevant circuit breaker; and

Tripping fee (£/unit/trip) – paid when a signal is sent to the relevant circuit breaker of a generator causing the generator to cease output to the transmission system.

If an intertripping scheme is installed by a generator, we may also offer a capability payment (£/settlement period) – paid for each settlement period in which the scheme is declared available. This payment might typically be structured to recover any associated installation, maintenance and training cost.