Hydrogen Above Ground Installations
The majority of our pipeline will be underground. However, we will need nine HAGIs at certain points along the pipeline.
This includes a Central Hub HAGI, which will act as the central connection point for each of the pipeline corridors.
HAGIs allow us to control the flow and pressure of the hydrogen and to facilitate inspection and routine maintenance of the pipeline. They will also act as the connection points to the Hydrogen Production Plant, Hydrogen Storage Facility and the spurs to the offtakers.
What HAGIs typically look like
HAGIs usually include a range of above ground equipment and structures. These structures are expected to be up to 3 metres in height, subject to final design.
Our HAGI sites will be protected by security fencing between 2.4 and 3.6 metres high with a gate allowing access. They usually require an access road linking the site to the local road network and places for workers to park their vehicles within the HAGI. In some cases, fences may need to be higher and additional security measures added. HAGIs will also need to connect into the local electrical distribution and telecommunications networks. Sites can vary in size depending on their specific use, but they typically range between 0.5 and 1.5 hectares (1 hectare is around the size of a football pitch). Your feedback and our work since the consultation in autumn 2022 informed the decision to reduce the number of HAGIs from ten to nine.
Minimising any potential visual and environmental impact
Outlined below are some of the ways we will look to mitigate any potential impacts:
- There may be some noise during construction, but we will abide by our commitments set out within the Outline Construction Environmental Management Plan (CEMP) to ensure that it is minimised and not significant.
- HAGIs will generally be largely screened from view with vegetation and/or fencing. Please see our outline landscaping plans for more information which are available in the Draft Environmental Statement.
- While we may need to turn on some lights during routine maintenance work, or in case of emergency, HAGI sites will generally be unlit. In sensitive locations permanent lights are likely to be approximately 3-5 metres high. We have prepared an Outline Lighting Strategy to inform our lighting design which is available in the Draft Environmental Statement.
- Once the Project is operational workers will be required to carry out essential checks and routine maintenance, but this will be fairly minimal and sites will not be manned 24 hours a day.
Interactive map
This map shows an overview of our proposals. It shows the area where our pipeline will be routed and temporary construction areas located, as well as potential Hydrogen Above Ground Installation (HAGI) and Block Valve Installation (BVI) locations.
See mapBlock Valve Installations (BVIs)
Two Block Valves are required as part of the Project; The Sworton Heath BVI would be located on the East Corridor, and the Hartford BVI would be located on the South Corridor.
BVIs act as a cut-off point to isolate a section of pipeline for maintenance, repair or safety reasons. These are smaller than HAGI sites, typically measuring around half a hectare (half a football pitch). Security fencing would be around 2.4 metres high. A gate will be required for access for maintenance. This is likely to include an access track (or similar) and space for vehicles to turn.
For more information about HAGIs and BVIs read the Design Evolution Report 2024 and Non-Technical Summary of the Environmental Statement via the knowledge hub.
Offtaker connections
Offtakers will also need to build some above ground infrastructure to connect to the hydrogen pipeline. The connection points would be smaller than BVI and HAGIs. These connections are generally located within the offtaker’s land and existing facilities.