North Wales and the Midlands boundaries
The Western transmission region includes boundaries in the Midlands and the north of Wales.
This includes the lower midlands boundary B9 and the north Wales boundaries NW1, NW2 and NW3.
The map below shows the general pattern of power flow directions expected to occur at winter peak in the years to come up to 2036, i.e. power will generally flow from north to south. The arrows in the diagram illustrate power flow directions and are approximately scaled relative to the winter peak flows.
Regional drivers
Power plant closures are set to occur in the Midlands with demand set to remain fairly high, driving increased power flows eastwards from future generation connecting to North Wales.
Presently, this region’s generation capacity has a significant volume of fossil fuel, however all pathways show this declining by 2035. The region shows a largely similar growth in both gross demand and generation capacity. Following 2035, North Wales and the Midlands is expected to generally export power, facilitated by the recommendations of the Beyond 2030 report.
The FES pathways suggest a total amount of transmission-connected generation capacity to be between 23GW to 25GW by 2030, from the current 20.5GW.
Generation Capacity
Gross Demand
A major increase in low-carbon and renewable generation capacity is accompanied by a slight growth in interconnectors and storage. The gross demand as seen from the transmission network in the region will increase across all scenarios, levelling out at around 2045 for Holistic Transition and Electric Engagement. For all pathways, fossil fuel generation is not present in the region by 2050.
The Midlands could experience significant low-voltage issues over future years with the expected closure of much of the traditional generation in the region, and the increase in transfer volumes across the region. In future years, during high loading conditions, especially during high winds, we could require additional local solutions to manage low voltages on the north-to-south transmission routes across B9.
Boundary regions
Click on the regions below to expand the boundary and understand its capability and challenges.
If you would like to learn how to interpret the graphs, click the button below.
The graphs show a distribution of power flows for each of our Future Energy Scenarios, in addition to the boundary power transfer capability and NETS SQSS requirements for the next 20 years.
Each scenario has different generation and demand so produces different boundary power flow expectations. From applying the methodology in the NETS SQSS for wider boundary planning requirements (as discussed in the previous chapter), we determine for each scenario:
- The economy criteria - solid coloured line
- Security criteria - dashed coloured line
- Current and future NOA capability (where available) - solid red line
The capability line (red line) is based on the recommendations from the Beyond 2030 report. More information about the NOA methodology can be found here. The 50%, 90%, economy required transfer (RT) and Security RT are calculated from the 2023 FES and ETYS processes. Where the NOA transfer capability is not available, there is a red line that provides the transfer capability from ETYS 2022.
Note: Boundary capability line is affected by the generation and demand profiles within each FES background. Therefore, the graphs are provided for indicative purposes only and cannot be directly compared.
The calculations of the annual boundary flow are based on unconstrained market operation, meaning network restrictions are not applied. This way, the minimum cost generation output profile can be found. We can see where the expected future growing needs could be by looking at the power flows in comparison with boundary capability.
View an interactive version of the graph
On each graph, the two shaded areas provide confidence as to what the power flows would be across each boundary:
- The darker region shows 50% of the annual power flows
- The lighter region shows 90% of the annual power flows
From the regions, we can show how often the power flows expected in the region split by the boundary are within its capability (red line). If the capability of the boundary is lower than the two regions over the next 20 years, there might be a need for reinforcements to increase the capability. However, if the line is above the shaded regions, it shows that there should be sufficient capability here and that potentially no reinforcements are needed from a free market power flow perspective until the shaded regions exceed the capability (red line).
Developments in the east coast and the East Anglia regions, such as the locations of offshore wind generation connection and the network infrastructure requirements, will affect the transfer requirements and capability of boundary B9.
In all FES, the expected flows increase to above the boundary capability for B9 after 2030. Expected flows have fallen compared to ETYS 23, similar to B7a & B8.
The FES show a lot of variable renewable generation in the north, meaning the spread of boundary power flows is very wide. During periods with low northern generation output it is credible to have power flowing from south to north feeding northern demand.
Boundary flows and base capability
View an interactive version of the graph
The capability line (in red) is based on the recommendations from the Beyond 2030 optimal path which uses the 2023 FES and ETYS data as inputs. The 50%, 90%, Economy RT and Security RT lines are based on FES 2024 and Clean Power 2030 pathways. The ETYS and NOA methodologies for this boundary are different and can result in different transfer capabilities.
The boundary capability is limited to 12 GW due to a voltage constraint for a fault on the Spalding North – Walpole – Bicker Fen 400kV circuits.
North Wales
Boundary regions
Click on the regions below to expand the boundary and understand its capability and challenges.
There is currently very low amounts of transmission-connected generation behind NW1 following the closure of Wylfa power station in 2015. However, there is some renewable and storage plant. Due to this low generation behind the boundary - it is expected within the later years for NW1 to become predominantly importing.
Boundary flows and base capability
View an interactive version of the graph
The capability line (in red) is based on the recommendations from the Beyond 2030 optimal path which uses the 2023 FES and ETYS data as inputs. The 50%, 90%, Economy RT and Security RT lines are based on FES 2024 and Clean Power 2030 pathways. The ETYS and NOA methodologies for this boundary are different and can result in different transfer capabilities.
The boundary capability is limited by the infrequent infeed loss risk criterion set in the SQSS, currently 1.8GW.
Currently, there is not a significant amount of generation behind NW2, mainly pumped storage and offshore wind projects.
Expected transfers across NW2 post-2028 will rise due to the additional offshore wind generation projects landing within the boundary, planned reinforcements in the area will facilitate this new generation capacity.
Boundary flows and base capability
View an interactive version of the graph
The capability line (in red) is based on the recommendations from the Beyond 2030 optimal path which uses the 2023 FES and ETYS data as inputs. The 50%, 90%, Economy RT and Security RT lines are based on FES 2024 and Clean Power 2030 pathways. The ETYS and NOA methodologies for this boundary are different and can result in different transfer capabilities.
The boundary capability is limited to 1.4 GW due to a thermal constraint on the Pentir - Trawsfynydd 400kV circuit.
The profile of NW3 is largely similar to that of NW2.
Expected transfers across NW3 post-2028 will rise due to the additional offshore wind generation projects landing within the boundary, planned reinforcements in the area will facilitate this new generation capacity.
Boundary flows and base capability
View an interactive version of the graph
The capability line (in red) is based on the recommendations from the Beyond 2030 optimal path which uses the 2023 FES and ETYS data as inputs. The 50%, 90%, Economy RT and Security RT lines are based on FES 2024 and Clean Power 2030 pathways. The ETYS and NOA methodologies for this boundary are different and can result in different transfer capabilities.
The boundary capability is limited to 5.5 GW due to a thermal constraint on the Connah’s Quay - Bodelwyddan - Pentir 400kV circuit.