Our proposals

Project overview

There are two main parts to Longmarsh Green Energy – the Western Site located to the north-east of the village of Tilney St Lawrence, and the Eastern Site, located near to the villages of Fincham and Barton Bendish.

The site boundary shown reflects the project’s expected overall land requirements, including cable routes to connect the different parts of the proposals.

Key infrastructure

Solar panels

We are proposing a mix of fixed and tracker solar panels, which adjust their position to track the sun throughout the day. Panels would generally be south facing except in fields where an east-west arrangement is required to avoid environmental effects. Panels would have a maximum height of 4.5m.

Solar panels would be mounted on metal frames, with piles driven into the ground to a depth of between 1m and 3m, depending on ground conditions. Panels would be at least 3.2m away from security fencing and a minimum of 30m from nearby homes and other amenity sensitive receptors.

Battery storage

Battery containers would be a maximum of 4.5m high with integrated heating, ventilation and air conditioning (HVAC) equipment, fire detection and suppression systems.

The battery storage element of the project will comply with relevant National Fire Chiefs Council guidance to ensure appropriate equipment spacing, emergency access and water supply.

Collector and intermediate substations

Collector compounds are hubs where electricity generated from multiple solar panels is collected. They would include transformers and switchgear (switches, fuses and circuit breakers, which allow the control, protection and isolation of electrical equipment). String or central inverters would be used to convert the DC electricity generated by the solar panels into AC. String inverters would be connected to the solar panel mounting structure while centralised inverters would be located within the Collector Compounds.

Intermediate substations would be located across the site to aggregate the output from multiple Collector Compounds prior to distribution to the Export Substation.

Export substations

The Eastern Site and Western Site would both include a substation. The Eastern Site Substation will transfer electricity from the Eastern Site to the Western Site. The Western Site Substation will allow the import of electricity where required (for the data centre campus and battery storage) and the export of electricity to the grid. Substations include electrical infrastructure such as transformers, switchgear and metering equipment. They are also expected to include a control building, office space, welfare facilities and spare parts storage.

Safety and security

Operational areas of Longmarsh Green Energy would be fenced using agricultural wooden posts with wire mesh fencing at an expected maximum height of 2.5m. Pole-mounted closed-circuit television (CCTV) systems with an expected maximum height of 5m would be located around the perimeter of the site boundary.

Metal palisade fencing with an expected maximum height of 3.0m would be installed around the data centre and any high voltage electrical infrastructure (including the collector compounds, substations and battery storage areas).

High-voltage electrical infrastructure areas would also include emergency lighting, in accordance with relevant standards, but the solar areas within the site would not be permanently lit.

Eastern Site

The Eastern Site would contain solar panels and battery storage, with the substation located in the western part of the site at least 300m from the nearest homes and other amenity sensitive receptors.

Western Site

The Western Site would contain solar panels, battery storage and a co-located data centre campus. The data centre campus and the Western Site Substation would be located in the centre of the site at least 300m from nearby homes and other amenity sensitive receptors.

Data Centre Campus (Western Site)

The development of data centre infrastructure is critical to enabling the UK economy to compete in the 21st Century. This type of development can deliver significant local benefits. However, we recognise it is important to also ensure the facts regarding the likely environmental considerations for this type of infrastructure – and how we will look to limit any impacts – are understood.

Local benefits

1. Significant investment in the region – the proposed data centre campus could result in over £25bn of capital investment in the region (including IT servers).
2. Employment – likely to provide thousands of construction jobs, over 500 permanent roles and will support a further 1,500 additional jobs.
3. Business rates – expected to result in over £20m in local business rates paid annually which could be used by the local authorities for local improvements.
4. Local community benefits – this significant investment also provides opportunities to fund local community projects and initiatives and we are keen to understand opportunities where these can be delivered.

Environmental considerations

1. Landscape and visual impact – the data centre campus will be located at least 300m from nearby homes and other amenity sensitive receptors. As we develop our proposals we will seek to further minimise impacts, including landscaping to help screen the campus from publicly accessible views.
2. Noise – the remote location of the data centre campus, 300m from nearby homes and other amenity sensitive receptors, will help to limit any noise impacts. As we develop our proposals we will include other noise mitigations (for example acoustic louvres) if needed.
3. Lighting and security infrastructure – the data centre will require additional security and external lighting, but this would be designed in line with standards and guidance to limit effects for local residents.
4. Water usage – the data centre campus is expected to use a sealed closed-loop cooling system, where a fixed volume of water or cooling fluid continuously recirculates to remove heat. This means that water needed for the data centre will be limited to domestic/amenity uses and there should be no significant impact on local water supply.
5. Air quality – backup fossil-fuel generators are included for emergency purposes only. These will be assessed as part of the ES but, absent emergency use, would only be operated for limited hours each year for testing. The remote site location and the distance from nearby receptors will minimise the impact of any emissions on local air quality.
6. Electricity prices – the data centre is co-located with solar which reduces its demand for electricity from the grid. In addition, locating the data centre campus in this region allows it to access supply from existing and significant new offshore wind generation and therefore is not expected to have any local impact in terms of electricity supply or the prices paid by local consumers.

Connecting our sites to each other and to the grid

We are proposing a combination of overhead lines and underground cable sections to link the sites to each other and to the grid.

Overhead lines will be used where overall impacts are more limited and where this allows potential impacts on existing drainage, the Great River Ouse, Network Rail infrastructure or the Strategic Road Network to be avoided. In other locations, underground cabling would be used to reduce effects on sensitive environmental receptors, including high value heritage assets.

The Western Cable Route would link the Western Site to National Grid’s Walpole Substation so that electricity can be exported and imported. The majority of the Western Cable Route would be overhead, with a length of approximately 8km and would be located between two existing electricity overhead lines. A section of the Western Cable Route within the Western Site would be underground to pass under an existing National Grid overhead line.

Near to Walpole Substation the cabling would be transferred from overhead line to underground cabling to allow it to pass under existing overhead lines and access the point of connection.

The site boundary near to Walpole Substation will be refined prior to submission once the exact route and point of connection is confirmed.

The Eastern Cable Route would connect the Eastern and Western Sites using a combination of overhead lines and underground cabling. We are proposing that the underground cabling would run for around 8km between the Eastern Site and A10/A134 junction. There are no existing overhead lines in this area and taking this approach would also avoid impacts on Stradsett Hall Registered Park and Gardens and heritage assets including the Grade 1 listed Church of St Botolph. The overhead section of line would run for around 8km, to the south of National Grid’s existing overhead line. All of the connections between the different parts of the Eastern Site would be underground.

We are aware that a number of projects are in development or construction near to Walpole Substation, including a number of National Grid projects. The impact of this project near to Walpole is limited to an underground cable in the immediate vicinity of the existing substation and then an overhead line to the east, located within the corridor of the existing overhead lines.

Construction, operation and decommissioning

Construction

Construction is expected to take place in phases. Should the project be granted a DCO, we anticipate construction activities starting in 2029, with the Western Site, Eastern Site and cable routes built in parallel and operational by 2032.

We will carefully assess and develop management plans to limit effects on local communities and the surrounding environment.

Our DCO application will include an outline Construction Traffic Management Plan explaining how we will manage transport movements to minimise and control impacts on local residents and roads, including commitments to delivery routes and construction hours. An outline Construction Environmental Management Plan will set out site specific procedures and mitigation measures to monitor and control environmental impacts related to the workforce and compound requirements.

New accesses would be provided from the existing road network for construction works. These would be located appropriately, considering aspects such as highways safety. On-site access improvements (for example improved crossings for existing drains) would be provided during construction.

Operation

Once operational, solar farms generate electricity relatively quietly and are not disruptive to neighbours. Maintenance activities for the solar farm include:

• regular inspection of all infrastructure, with testing and servicing as required;
• cleaning of solar panels, if required;
• repair or replacement of damaged components; and
• landscaping and vegetation management.

The data centre campus would provide permanent employment opportunities. Typically, data centres operate continuously on different shifts to ensure appropriate staff cover at all times. Operational traffic routes and staff travel will be controlled by management plans as required.

Decommissioning

Decommissioning of the solar farm will take place after 60 years of operation.

At the Eastern Site, all above-ground infrastructure will be removed.

The Western Site data centre will remain, along with the Western Site substation and battery storage to support data centre operations. The Western Cable Route will also be retained. All Western Site solar generation infrastructure will be removed.

We will recycle or dispose of materials in line with industry best practice at the time.

Decommissioning is expected to take around 18 months, with activities and effects similar to the construction phase. Once decommissioning is complete, the land – apart from certain biodiversity and enhancement mitigation areas – would be restored to a condition where it could be returned to its current agricultural use.

How to find out more

More information about our proposals is available in the Community Consultation Leaflet.

You can provide your comments on the plans in the Consultation Feedback Form.