Map

Explanatory note

Published 22 November 2021

Purpose and content of the map

Under the Offshore Transmission Network Review (OTNR), the National Grid Electricity System Operator (ESO) is currently developing a Holistic Network Design ^{[footnote 1]} (HND) for those offshore wind projects that are covered by the Pathway to 2030 workstream of the OTNR. These are, broadly speaking, projects that are aiming to be operational towards the end of this decade and are not already covered under the OTNR Early Opportunities workstream. In developing the HND, the ESO is bringing together onshore and offshore network planning. Seeing the transmission system as a whole will allow to develop an optimum engineering solution for the transmission infrastructure that connects the offshore wind projects to the network in a coordinated way. Objectives for the development of the design are that it should be cost-efficient and deliverable, but also minimise the impact new coordinated infrastructure has on communities and the environment.

Developing this design requires, amongst others, an informed view on where the offshore projects will likely be located, and when they will likely be operational and ready for connection. To provide this view, TCE has used its geospatial expertise to create a bespoke Generation Map. This map illustrates a potential development pathway for offshore wind projects in Great Britain over the next decade, using publicly available data. It also shows a broader spatial context for offshore development by including the onshore transmission system, offshore cable routes (where known), and other offshore assets such as aggregates production areas and Carbon Capture & Storage (CCS) sites. It also includes data on marine environmental constraints, such as protected areas.

In addition to serving as a building block for the development of the HND, the Generation Map also provides an additional source of information for Ofgem when making regulatory decisions, for example, in the context of the price control framework for transmission infrastructure.

Map format

TCE have developed the Generation Map in 2 file formats - pdf and Geographic Information System (GIS).

The pdf file shows a flat profile of the information. This is the Generation Map published on the OTNR website. In addition to this overall map which shows all activity, TCE have also produced a series of pdf maps, one for each year through the period being considered. These maps show the projects for each year, adding the projects of the respective year to the individual map of the previous year. As these individual maps do not contain any information that is not already contained in the overall map, we only publish the overall Generation Map.

In addition, TCE has also made the information available via a mix of GIS shapefiles and links to access other publicly available GIS data. Once uploaded into their own GIS systems, users such as the ESO will have the data in a more interactive format. This data is not readily accessible, and special GIS software is required to read this data.

We therefore only publish the pdf file on the OTNR website, as it is an accessible format in which the map can readily be understood.

Information sources

Information on offshore project locations was taken from TCE’s seabed lease agreements. Further information on connection dates was taken from National Grid’s TEC Register. The pdf file with the Generation Map includes additional information on the data used and a list of the data sources that served to build the Generation Map.

Frequently asked questions

Why is there no information on project capacity in the map?

Information on project capacity is not included in the Generation Map as this is not directly relevant to the purpose of the document. The latest position on the contracted capacity for any given project can be found on the ESO’s TEC Register.

Why are cable corridors for some projects on the map but not for others?

The map only includes cable corridors for which TCE has data, either from their own seabed leasing agreements or from publicly available sources.

The map indicates 2033 as connection date for LR4 projects – does that mean the HND seeks to connect them at that time?

The Generation Map uses the best publicly available information, including on connection dates. These dates are the connection dates contained in the TEC Register. For the development of the HND these dates are not taken as set connection dates. The actual connection dates will depend on a variety of factors, and the Pathway to 2030 workstream intends to contribute to a timely connection of those projects up to 2030.

Why does one project on the map have an unknown connection date?

At the cut-off date of the map, there was no publicly available information on the connection date for this project.

Why do the projects around Scotland not have project names?

The ScotWind seabed leasing round is still ongoing. Results had not been announced at the time of publication of the Generation Map. Therefore, the map can only show the ScotWind bidding areas (shown in red outlines). Once the ScotWind leasing results are published by Crown Estate Scotland, this will inform the further process in the Pathway to 2030 workstream, in particular the HND.

Glossary of terms

The following is a glossary of terms used in the Generation Map and in this explanatory note.

• CES: Crown Estate Scotland: Crown Estate Scotland manages the seabed around Scotland.
• CCS: Carbon Capture & Storage.
• ESO: National Grid Electricity System Operator: The operator of the electricity system for Great Britain.
• HND: Holistic Network Design: A network design, currently being developed by the ESO, to connect the offshore wind projects covered by the Pathway to 2030 workstream of the OTNR in a coordinated manner.
• National Grid: in the Generation Map, ‘National Grid’ refers to National Grid Electricity Transmission, the Transmission Owner in England and Wales.
• Ofgem: The Office of Gas and Electricity Markets: Supporting the Gas and Electricity Markets Authority, the government regulator for the electricity and downstream natural gas markets in the United Kingdom.
• OTNR: Offshore Transmission Network Review: The review looks into the way that the offshore connections are designed and delivered, seeking more coordination.
• TEC Register: Transmission Entry Capacity Register: A list of offshore wind projects that hold contracts for Transmission Entry Capacity with the ESO.
• TCE: The Crown Estate: The Crown Estate manages the seabed around England, Wales and Northern Ireland.
• ScotWind: The seabed leasing round off the Scottish coast, currently being run by the Crown Estate Scotland. Results on this are expected in early 2022.
• LR4: Leasing Round 4: This refers to the latest seabed leasing round run by TCE. In February 2021, TCE announced the six projects that were granted preferred-bidder status.
• SSEN: Scottish & Southern Electricity Networks: 1 of 2 Transmission Owners in Scotland.
• SP: Scottish Power Energy Networks: 1 of 2 Transmission Owners in Scotland.
• UG cable: Underground cable.

1. More information on the Holistic Network Design is available in the OTNR Summer Webinar Slide Pack ↩