Skip to content

Flexibility – Requirements

Latest analysis tranche reference: T8A


We are looking to mitigate a range of constraints across multiple voltage levels on the network. As they involve different methods of assessment and operation, our Constraint Management Zones (CMZs) are split into HV Zones, covering constraints at 33kV and above, and LV Zones, covering constraints on our 6.6kV and 11kV networks.

Our HV Zones have Secure and/or Dynamic products available, and, where applicable, Sustain (also referred to as HV Sustain). In LV Zones we are only looking to procure Sustain services (also referred to as LV Sustain) from providers connected at lower voltages. Sustain is operated the same way across both LV and HV zone, with the same parameters and customer eligibility; HV or LV is only to differentiate between constraint levels.

More information on all products can be found in our latest Procurement Statement. Information on all the constraints we have assessed can be found in the Distribution Network Options Assessment (DNOA).

We undertake flexibility analysis on a regular basis, and we will keep updating this data in line with the latest tranche of analysis.


The data covers overall zonal requirements, including locational data.

Full information on HV Zones is available in the Some useful information has been extracted into csv data files, and the SQL queries used for this are available within the compressed zip file. However, some reports below have been manually edited to improve readability and reduce the number of files, so running queries may not always produce an exact match.

OVERVIEW_All_Zones.csv provides a list of all Constraint Management Zones (CMZs), both HV and LV, which are or will shortly be open for procurement. This file contains some basic information such as the main product and service type in the zone, and provides an indication of how many zones we have active in each Licence Area.


Information on where we require flexibility services is contained in the following Postcodes and Polygons files, for combined HV and LV zones. These are updated with each tranche of analysis as zones change and as we improve our data accuracy over time.

As with all geographic data, the Postcodes and Polygons are indicative only and final mapping of assets to zones will be carried out on an asset by asset basis following their registration on Market Gateway. The list of postcodes is deliberately broad, to avoid excluding assets from participation. Wider work is being carried out to improve the accuracy of this data.


We look to procure Sustain services within our LV Zones, which is a simple and less targeted product compared to Secure or Dynamic. HOW_MUCH_and_WHEN_LV_Zones.csv provides information on how much (minimum and maximum kW) we look to procure, the maximum price we can pay (ceiling price), and the delivery periods, which are the same across all zones. The minimum kW value relates to a minimum we would look to procure in order to defer reinforcement, and NOT to a minimum capacity of an asset. If this is not met, we may decide to progress reinforcement and not award flexibility services.

The requirements for our HV zones, such as the estimated peak capacity (MW), energy (MWh), and the ceiling prices, are presented in HOW_MUCH_HV_Zones.csv. Moving to ceiling prices means that the maximum price is now linked with the volume of flexibility required, therefore in most cases ceiling prices will decrease over time as the amount of flexibility required generally tends to grow.

As the requirements for our HV Zones are more complex, granular, and targeted, information regarding when we may need flexibility services is presented in two forms:

  • a simplified, monthly breakdown of potential needs over the years (WHEN_HV_Zones.csv), which should provide an overview of needs over time, and

  • as half-hourly peak MW profile data in WHEN_HV_Zones_MW_Profiles.csv for a year; full profile data is available in the database.

Each trade opportunity will contain details of final volumes and delivery periods. Information on trades is available on the Flexibility – Trades Data and Results page.

Data Files

Name Format Last Changed Download
HOW MUCH and WHEN LV Zones csv
4 months ago
HOW MUCH HV Zones csv
4 months ago
WHEN HV Zones csv
4 months ago
WHEN HV Zones MW Profiles csv
4 months ago
Flexibility Database and Queries zip
4 months ago
OVERVIEW All Zones csv
4 months ago
WHERE All Polygons gpkg
4 months ago
WHERE All Postcodes csv
4 months ago

Additional Info

Field Value
Uploaded Date August 24, 2023, 13:03 (UTC)
Creator National Grid Electricity Distribution
Rights NGED Open Data Licence
Contributor Digitalisation & Data
Language EN
Data Classification Open
Update Frequency Not Applicable

Integrate this dataset using cURL

# Get a list of dataset's resources

curl -L -s | grep path

# Get resources

curl -L
curl -L
curl -L
curl -L
curl -L
curl -L
curl -L
curl -L