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System Operating Plan (SOP)
Summary
This is a data release describing NESO's System Operating Plans (SOPs) - operational documents produced multiple times daily at peak/trough demand periods to guide real-time electricity system balancing decisions. The publication includes a detailed glossary of technical terms used in SOPs and notes about data quality issues and planned file deletions in January 2026.
Why it matters
Provides transparency into NESO's real-time operational planning processes and the technical parameters used for system balancing, which helps market participants understand how operational decisions are made that affect wholesale electricity prices and system security.
Key facts
- •SOPs published daily for cardinal points: 1A, 1B, 2F/A/B, 3B, 3C & 4B
- •Files from June-September 2020 and June 2021 will be deleted on 14th January 2026
- •Currently experiencing data quality issues with published SOP data
- •Document published 2020-06-05
Timeline
Effective date14 Jan 2026
Areas affected
wholesale marketgeneratorstransmissionflexibility
Related programmes
Market-wide Half-Hourly Settlement
Publisher description
As part of our daily planning processes within the ESO control room, the control room strategy team produces a System Operating Plan (SOP) at key demand peaks or troughs throughout the day, at what we call a Cardinal Point (CP). Prior to each CP the Strategy team hand over the relevant SOP to the real-time Energy team, who then use this plan to take real-time operational decisions to balance the electricity system. <br/><br/> The SOP is a snapshot of key information that is available to the E
Full extracted text
As part of our daily planning processes within the ESO control room, the control room strategy team produces a System Operating Plan (SOP) at key demand peaks or troughs throughout the day, at what we call a Cardinal Point (CP). Prior to each CP the Strategy team hand over the relevant SOP to the real-time Energy team, who then use this plan to take real-time operational decisions to balance the electricity system. <br/><br/> The SOP is a snapshot of key information that is available to the ENCC at that time of its creation and based on this information provides a flexible strategic plan to ensure the ESO fulfills all its obligations to balance the system. <br/><br/> The information within the SOP ensures that the most economic, secure, and flexible plan is developed for that moment in time at the time of handover. <br/><br/> The real-time energy team constantly reviews the information within the SOP to ensure it is still relevant as they approach the CP, so that to ensure the operational plan is still valid, and if required modify as needed. <br/><br/> On this page, we aim to publish the following SOPs every day ahead of the respective cardinal point: 1A, 1B, 2F/A/B (whichever is the peak of the morning), 3B, 3C & 4B. <br/><br/> For further background on the SOP please view our [Introduction to SOPs document](https://www.nationalgrideso.com/data-portal/system-operating-plan-sop/an_introduction_to_system_operator_plans), additionally, you can find explanations of the terms used in the SOP in our [SOP Glossary document](https://www.nationalgrideso.com/data-portal/system-operating-plan-sop/glossary_of_terms_used_in_system_operating_plan). >**<span style="color: rgb(176,74,42)">NOTE:</span>** <b>We are currently experiencing issues with the quality of the published SOP data in the Data Portal. Our team is actively investigating the matter and working towards a resolution. We apologize for any inconvenience this may have caused.</b> <b> **<span style="color: rgb(176,74,42)">NOTE:</span>** On 14th January 2026, the below files will get deleted from this dataset as the files are in the non-structured format and some of the data on the below files are already available in System Operating Plan - Data Table data file: <br/> 1. Published SOP - Jun 2021 <br/> 2. Published SOPs September 2020 <br/> 3. Published SOPs August 2020 <br/> 4. Published SOPs July 2020 <br/> 5. Published SOPs June 2020</b> Public 1 Glossary of terms used in a System Operating Plan (SOP) A System Operating Plan is a snapshot in time, usually produced for the peaks and troughs of the Demand Curve (Cardinal Points). The SOP provides a plan to meet System Demand and Reserve Requirements and ensure that any constraints are satisfied. All the information presented in the SOP is based on market submissions and Operating Margin requirements at the time of creation of the SOP. Term Description Methodology Customer Demand Forecast National 5-minute spot demand Calculated by NESO Station Transformer Assumed total national station demand Calculated by NESO Demand Side Balancing Reserve (DSBR) NOT VALID ANYMORE NOT VALID ANYMORE Total SOP Demand Customer Demand + Station Transformer Customer Demand + Station Transformer Standing Reserve Requirement (SRR) A different term for STOR (Short Term Operating Reserve). A fixed value depending on the GMT or BST. Calculated value by NESO Standing Reserve Availability (SRA) The amount of STOR that is usable is the sum of the STOR declared available. Calculated by NESO systems Standing Reserve Shortfall Difference between the STOR requirement minus the STOR usable indicates if there is a standing reserve shortfall. Automatically calculated by NESO systems. Public 2 Standing Reserve Excess (SRE) Indicates if there is an excess of Standing Reserve. Calculated by SRR - SRA. Automatically calculated by NESO systems. Standing Reserve Wind Adjustment Automatically calculated value, used to adjust the standing reserve requirement figure to take into account the potential wind forecasting error Automatically calculated by NESO systems (Set to 0MW/Null as not currently used in Operating Margin Calculations) Net Positive Regulating Reserve (PRG) Regulating reserve is designed to cover for expected levels of plant loss plus demand forecast error that occurs for a specified cardinal point between the final SOP production time and real time. Calculated by NESO Positive Regulating Reserve Wind Adjusted (WPRR) Automatically calculated value to take into account the potential wind forecasting error. Automatically calculated by NESO systems Reserve for Response (PRE) Reserve for response is the amount of reserve that needs to be allocated to synchronised generators so they can be pulled back and instructed to hold frequency response Public 3 Total Positive Reserve C [... truncated]