Value chain · CLM-0796
In plain terms
Britain's system operator says its grid needs both spinning inertia and short-circuit strength, and gives a scale: a single 2 gigawatt coal station used to supply over 6,500 megavolt-amperes of that strength.
The claim as recorded
The GB system operator's Clean Power 2030 operability annex states that system stability requirements primarily cover inertia and system strength quantified by Short Circuit Level, that system inertia is currently kept always above 120 GVAs with a reduction to 102 GVAs expected and remaining at that level for Clean Power 2030 operation, that additional Short Circuit Level requirements have been identified mainly in the north of Scotland, the East Midlands, South Wales and western England, that for scale a 2 GW coal-fired power station would roughly have provided a combined Short Circuit Level support of over 6,500 MVA, and that the peak residual inertia requirement in 2030 may be as high as 35 GVAs to be met through new stability markets and the Balancing Mechanism.
Scope and limits
The source's 6,500 MVA is explicitly approximate and is a comparator for a coal station, not a requirement. This claim establishes the scale of short-circuit level that a large synchronous plant supplies and the GB regional pattern of need. It does NOT establish what any SBSP ground converter would contribute, which no source found addresses, and the arithmetic of substituting one for the other is not attempted here.
What it assumes
That the 6,500 MVA figure is a rough scale figure as the source labels it ("roughly", "For scale"), not a design value for any specific station.
Where it comes from
Definition, verbatim: "Large fossil-fuelled power stations have traditionally supported system stability by providing inertia and system strength. As weather-dependent renewables supply an increasing proportion of electricity demand, the system will become less stable without additional services. Our requirement for system stability primarily covers inertia and system strength (quantified by Short Circuit Level (SCL))." Inertia level, verbatim: "We currently ensure system inertia is always above 120 GVAs. The system inertia limit is reviewed annually through the Frequency Response and Control Report (FRCR). This limit is expected to be reduced to 102 GVAs in the future to support zero carbon operation, due to the work we have undertaken to prepare for zero carbon operation in 2025. It is expected to remain at 102 GVAs for the Clean Power 2030 operation." SCL requirement and the coal comparator, verbatim: "As well as inertia, there will be additional Short Circuit Level (SCL) requirements to maintain stable operation of renewable generation sources and to keep voltage stable during and immediately after system disturbances, as indicated in Figure 1. Most SCL requirements have been identified in the north of Scotland, East Midlands, South Wales and western England regions. For scale, a 2 GW coal-fired power station would have roughly provided a combined SCL support of over 6,500 MVA." Residual inertia, verbatim: "Our peak residual inertia requirement in 2030 may be as high as 35 GVAs and will need to be met using a combination of our new stability markets (mid-term and long-term markets) and the Balancing Mechanism." Grid-forming as a mitigation, verbatim: "Installation of new grid-forming technology can reduce additional stability requirements and, alongside obligations in the Grid Code for users, Transmission Owner (TO) built High Voltage Direct Current (HVDC) links with grid-forming characteristics can also play an important role in supporting system stability."
Basis: system inertia in GVAs; system strength quantified as Short Circuit Level in MVA; 2030 planning horizon
Related records
- Answers question
- QST-012 not published in this release
Cite this
energyaperture.com/c/clm-0796
CLM-0796, Energy Aperture, as of 2024.