National Grid ESO debuts new fast frequency service

October 1, 2020

National Grid Electricity System Operator (ESO) will launch its new fast frequency response service  to enable it to respond rapidly to disturbances in the flow of energy around the grid. Dynamic Containment is first in batch of products to help balance a UK power grid featuring more variable generation

The ESO’s new sub-second, post-fault response capability, called Dynamic Response, will go live in the national control room. The tool is the first in a suite of new fast-acting frequency services to be introduced by the ESO to maintain the system close to 50Hz.

Six tenders have been received and two battery energy storage units accepted in the first round to provide 90 MW of fast response services over 24 hours, with six units and 165 MW available to compete in tomorrow’s day ahead tender.

The soft launch of the new service will see the ESO running tenders for Dynamic Containment seven days a week, procuring from 11pm-11pm.

This moves the frequency response market closer to real-time in a similar arrangement to the model the ESO has been trialling through its frequency response auction trial.

Initially 500 MW of low frequency response will be bought from providers, which is set to evolve to 1 GW next year and to include high frequency response.

All technology types can participate, with batteries anticipated to make up the majority of providers in the early phase while the service is being developed in conversation with industry, said National Grid ESO.

The new service will sit alongside the ESO’s existing frequency products for now, rather than replacing any.

Dynamic Moderation and Dynamic Regulation products will complete the suite later, with the former designed to manage sudden frequency imbalances in intermittent generation (for example during gusting winds) and the latter to manage small deviations when frequency is close to 50 Hz.

Rapid and real-time management of frequency is becoming increasingly important as the ESO operates a system with more renewable generation and less inbuilt inertia – inertia being a key influencing factor in how quickly frequency will change when there is a system imbalance.

The dynamic product suite’s frequency response capability will complement the ESO’s stability pathfinder initiative, which is already finding new ways to provide inertia without relying on it as a by-product of electricity generation through fossil fuel plants.

In July Drax Group’s Cruachan plant started providing inertia without generating power, while providers Statkraft and Welsh Power are installing new equipment at their Keith and Rassau sites respectively to provide grid stability services.

National Grid ESO national control head and chief engineer Ro Quinn said: “This summer gave us unprecedented insight into what operating a zero carbon electricity system with low inertia could look like.

“Although at times we needed to take more actions to make sure we kept the system secure, I’m proud that our control room proved equal to the engineering challenge.

“Dynamic Containment will be a game-changer.

“The boost the new service will bring to our frequency response capability will further strengthen the system and our ability to maintain a safe and secure electricity supply.

“It will also allow us to bring more renewable generation into the electricity mix, meaning more progress towards our zero carbon ambition.”