SONI064 – DS3 System Services – Volume Capped – Gate 13

Following review by the Regulatory Authorities of the TSOs’ Report on Ensuring a Secure, Reliable and Efficient Power System in July 2011 the TSOs were requested by the SEM Committee to put in place a programme of work to solve the challenges associated with increased levels of penetration of variable non-synchronous renewable generation. Primary Operating Reserve or ‘POR’ has the meaning given to it in the grid code

Secondary Operating reserve or ‘SOR’ has the meaning given to it in the grid code Tertiary 1 operating reserve or ‘TOR1’ has the meaning given to it in the grid code.

Tertiary 2 operating reserve or ‘TOR2’ has the meaning given to it in the grid code RR (De-synchronised)’ means replacement reserve provided by the providing unit when: (i) not Synchronised to the power system in the case of a synchronous providing unit, or (ii) when connected to the power system and operating at a level less or equal to 0 MW in the case of an energy storage providing unit, or (ii) when connected to the power system in the case of a demand side unit

RR (Synchronised)’ means Replacement Reserve provided by the Providing Unit when: (i) synchronised to the power system in the case of a synchronous providing unit, or (ii) when connected to the power system and operating at a level greater than 0 MW in the case of an energy storage providing unit or power park module. II.2.5) Award criteri

Steady-state reactive power or ‘SSRP’ means reactive power capability (Leading) and reactive power capability Synchronous Inertial Response (SIR) is the kinetic energy (at a Frequency of 50 Hz) of a centrally dispatched synchronous providing unit multiplied by the SIR factor (SIRF)

Ramping Margin 1 is the increased MW Output and/or MW Reduction that a providing unit can provide to the company within one hour of the company issuing a dispatch instruction to a service provider and that the providing unit can maintain for a further two hours after the one hour period has elapsed. It is limited by the lowest availability in that three hour period.

Ramping Margin 3 is the increased MW Output and/or MW reduction that a providing unit can provide to the company within three hours of the company issuing a dispatch instruction to a service provider and that the providing unit can maintain for a further 5 hours after the 3 hour period has elapsed. It is limited by the lowest availability in that 8 hour period

Ramping Margin 8 is the increased MW Output and/or MW reduction that a providing unit can provide to the company within eight hours of the company issuing a dispatch instruction to a service provider and that the providing unit can maintain for a further 8 hours after the 8 hour period has elapsed. It is limited by the lowest availability in that 16 hour period. Fast Frequency Response (FFR) is the additional MW Output or MW reduction required compared to the pre- incident MW output or MW reduction, which is fully available from a providing unit within 2 seconds after the start of an event and sustainable up to 10 seconds after the start of the event.