Senior leadership visit to UK battery gigafactory project

Earlier this month, JSM Group welcomed members of its senior management team to a major battery gigafactory project currently under construction in the UK. JSM is delivering the new 33kV electrical connection serving the site, which forms a critical part of the project’s infrastructure and long-term operational capability.

The visit provided an opportunity for senior leaders to walk the site, engage directly with the teams delivering the work, and gain first-hand insight into the scale and technical complexity of the development. Projects of this nature play a vital role in supporting the UK’s industrial growth and clean-energy ambitions, and JSM is proud to be contributing to this nationally significant scheme.

Commenting on the visit, Martyn Crocker, Operations Director at JSM, said:

The standard of work on site is genuinely impressive. Our teams are delivering complex, high-specification construction to a level of quality and precision that reflects the very best of what JSM stands for, and it was a privilege to see it first-hand.

JSM would like to thank everyone on site who supported the visit, as well as the project teams whose continued focus on safety, quality and programme delivery is helping to set the standard across the business.

The UK’s transmission and distribution networks are under unprecedented strain. Hyperscale data centres, renewable generation, and electrification of transport are driving demand profiles that far exceed historic norms, placing increasing pressure on power infrastructure and utility networks across the country. For years, developers have faced systemic bottlenecks: queue congestion, speculative applications, and opaque milestone tracking. The recent Connections Reform update from Ofgem and NESO marks a fundamental shift in how grid access is managed, and one that the infrastructure sector has long anticipated.

Why has grid access become such a critical constraint for infrastructure development?

Following the latest announcement, the readiness-based model under TMO4+ is now firmly embedded: “first ready and needed, first connected.” This replaces the legacy first-come-first-served approach, which allowed non-viable projects to occupy scarce capacity within the electricity network.

Under the new regime, Gate 2 offers are contingent on demonstrable readiness, land rights, planning consent, and strategic alignment with system needs. This change reflects the realities facing electric utilities infrastructure, where connection capacity must be prioritised for projects capable of delivery rather than speculative intent.

How does the readiness-based model support long-term network resilience? This reform is not simply a policy adjustment; it is a technical necessity. With more than double the required 381GW of generation and storage capacity for 2050 currently sitting in the connection queue, prioritisation is essential.

By aligning grid reinforcement and connection assets with projects that can progress, the new approach supports more effective planning across power infrastructure engineering, renewable energy infrastructure, and transmission networks, helping ensure investment delivers real-world outcomes.

What does connections reform mean for data centre developers? Data centres are now recognised as strategically aligned demand under NESO’s criteria, reflecting their role in the UK’s digital economy and wider data centre infrastructure ecosystem. However, alignment alone is no longer sufficient. Developers must clearly evidence readiness to avoid being deferred into Gate 1, where connection dates remain uncertain. For schemes targeting energisation before 2030, this places greater emphasis on accelerated planning consent, progression commitment fees, and compliance with whole-queue reordering protocols. Connection strategy has therefore become a defining factor in data centre design and infrastructure planning, influencing site selection, programme certainty, and long-term viability. [column_divider] How are industry stakeholders responding to the new connections landscape? This was a focal point at our April 2025 roundtable in partnership with Building Magazine: “Data Centres: Are We Doing Enough to Get Them Connected?” Industry stakeholders agreed that connection delays were the single largest risk to digital infrastructure delivery, often meaning that relocation was sought. The reforms confirmed in the latest update were widely recognised as a necessary step toward unlocking capacity for mission-critical developments and restoring confidence across the infrastructure services landscape. How can engineering readiness accelerate grid connections? At JSM Group, readiness isn’t just a regulatory checkbox, it’s an engineering challenge. Our teams integrate grid interface design, HV network engineering, and contestable works delivery with full administrative compliance for DNO and TNO processes. By managing every stage, from feasibility and route engineering to commissioning, we ensure projects meet readiness thresholds and secure early connection slots. Our turnkey delivery model provides a a single point of accountability, reducing risk and accelerating timelines. With more than 25 years’ experience delivering projects across power, telecoms, renewable energy, and utility infrastructure, we bring the technical depth and operational agility needed to navigate the complexities of queue management, connection agreements, and grid reinforcement planning. What role will connections reform play in the UK’s energy transition Connections reform is more than a regulatory update; it’s a structural evolution of the UK’s energy system. By embedding readiness criteria and enforcing milestone compliance, the industry can unlock latent capacity and accelerate the transition to a low-carbon, digitally enabled economy. Explore our capabilities and see how JSM can help you stay ahead: View Our Portfolio
By Peter Östlund, MD EU Operations at JSM Group At JSM UTILITY SERVICES (EU) GmbH, sustainability isn’t just a goal, it’s a core part of how we operate. Across our European projects, we are committed to reducing environmental impact while delivering exceptional service to our clients. We are implementing innovative practices to cut carbon emissions, optimise resource use, and embrace greener technologies. From adopting energy-efficient equipment to prioritising recycled materials, every decision is guided by our commitment to a more sustainable future.

Supply chain partners

A key part of this approach is collaboration with our supply chain partners. We work closely with suppliers to ensure a cohesive and aligned strategy that maximises sustainability impact. By setting clear expectations, sharing best practices, and prioritising environmentally responsible sourcing, we help deliver solutions that meet, and often exceed, our clients’ sustainability requirements. We also look across the wider JSM Group to adopt the latest sustainability initiatives and innovations. This ensures our EU operations benefit from group-wide expertise, shared learning, and best practices, enabling us to deliver consistent, forward-thinking solutions for our clients.

environmental standards

In addition, we are aligning with EU-wide environmental standards and supporting clients in meeting their own ESG objectives. By integrating sustainability into project planning and execution, we help build infrastructure that is not only reliable but also responsible. Looking ahead, we will continue to invest in solutions that minimise waste, enhance efficiency, and contribute to the transition toward a low-carbon economy. Together, we’re shaping a future where progress and sustainability go hand in hand. Our Group sustainability strategy focuses on reducing emissions, managing waste responsibly, protecting biodiversity, and promoting social value across our energy, civil engineering, and telecoms projects. Aligning with the United Nations Sustainable Development Goals (UN SDGs) enables JSM Group to take a focused and accountable approach to sustainability. The SDGs provide an internationally recognised blueprint for a more sustainable and equitable future, offering both a framework for action and a means of transparent reporting. Explore our capabilities and see how JSM can help you stay ahead: View Our Portfolio.

The UK’s transmission and distribution networks are under unprecedented strain. Hyperscale data centres, renewable generation, and electrification of transport are driving demand profiles that far exceed historic norms, placing increasing pressure on power infrastructure and utility networks across the country. For years, developers have faced systemic bottlenecks: queue congestion, speculative applications, and opaque milestone tracking. The recent Connections Reform update from Ofgem and NESO marks a fundamental shift in how grid access is managed, and one that the infrastructure sector has long anticipated.

Why has grid access become such a critical constraint for infrastructure development?

Following the latest announcement, the readiness-based model under TMO4+ is now firmly embedded: “first ready and needed, first connected.” This replaces the legacy first-come-first-served approach, which allowed non-viable projects to occupy scarce capacity within the electricity network.

Under the new regime, Gate 2 offers are contingent on demonstrable readiness, land rights, planning consent, and strategic alignment with system needs. This change reflects the realities facing electric utilities infrastructure, where connection capacity must be prioritised for projects capable of delivery rather than speculative intent.

How does the readiness-based model support long-term network resilience? This reform is not simply a policy adjustment; it is a technical necessity. With more than double the required 381GW of generation and storage capacity for 2050 currently sitting in the connection queue, prioritisation is essential.

By aligning grid reinforcement and connection assets with projects that can progress, the new approach supports more effective planning across power infrastructure engineering, renewable energy infrastructure, and transmission networks, helping ensure investment delivers real-world outcomes.

What does connections reform mean for data centre developers? Data centres are now recognised as strategically aligned demand under NESO’s criteria, reflecting their role in the UK’s digital economy and wider data centre infrastructure ecosystem. However, alignment alone is no longer sufficient. Developers must clearly evidence readiness to avoid being deferred into Gate 1, where connection dates remain uncertain. For schemes targeting energisation before 2030, this places greater emphasis on accelerated planning consent, progression commitment fees, and compliance with whole-queue reordering protocols. Connection strategy has therefore become a defining factor in data centre design and infrastructure planning, influencing site selection, programme certainty, and long-term viability. [column_divider] How are industry stakeholders responding to the new connections landscape? This was a focal point at our April 2025 roundtable in partnership with Building Magazine: “Data Centres: Are We Doing Enough to Get Them Connected?” Industry stakeholders agreed that connection delays were the single largest risk to digital infrastructure delivery, often meaning that relocation was sought. The reforms confirmed in the latest update were widely recognised as a necessary step toward unlocking capacity for mission-critical developments and restoring confidence across the infrastructure services landscape. How can engineering readiness accelerate grid connections? At JSM Group, readiness isn’t just a regulatory checkbox, it’s an engineering challenge. Our teams integrate grid interface design, HV network engineering, and contestable works delivery with full administrative compliance for DNO and TNO processes. By managing every stage, from feasibility and route engineering to commissioning, we ensure projects meet readiness thresholds and secure early connection slots. Our turnkey delivery model provides a a single point of accountability, reducing risk and accelerating timelines. With more than 25 years’ experience delivering projects across power, telecoms, renewable energy, and utility infrastructure, we bring the technical depth and operational agility needed to navigate the complexities of queue management, connection agreements, and grid reinforcement planning. What role will connections reform play in the UK’s energy transition Connections reform is more than a regulatory update; it’s a structural evolution of the UK’s energy system. By embedding readiness criteria and enforcing milestone compliance, the industry can unlock latent capacity and accelerate the transition to a low-carbon, digitally enabled economy. Explore our capabilities and see how JSM can help you stay ahead: View Our Portfolio
JSM Group, a leading provider of integrated utility infrastructure solutions, has commenced construction of the high voltage substation and cable route for maincubes’ new data centre campus in Nauen, Germany. The start of works follows the granting of the building permit for the energy infrastructure and represents a major milestone in the delivery of the mainHub Berlin campus. JSM Group is responsible for the delivery of the company owned 110 kV cable route and substation – critical components that will underpin the campus’s long term energy security and scalability. The approximately six kilometre cable route will transport electricity from renewable energy sources via the modern E.DIS distribution network to the site’s 110 kV substation.

Enabling high performance infrastructure for cloud and AI

The new campus has been designed with a grid connection capacity of 200 megawatts (MW), with further expansion options, to support high performance computing environments, including advanced AI workloads and complex data analytics. Through the delivery of this critical energy infrastructure, JSM Group is enabling a resilient, future proof power supply aligned with the demands of next generation digital services. maincubes selected Nauen as the site for its new campus due to the Berlin Brandenburg region’s stable energy supply, strong renewable generation from wind and photovoltaics, and favourable conditions for sustainable growth. The project further strengthens the region’s position as a hub for modern digital infrastructure. Oliver Menzel, CEO of maincubes, said:
The start of construction of the substation is the next visible step on our journey toward mainHub Berlin. In Nauen, a state of the art data centre location is being created – regionally rooted and internationally connected. In doing so, we are consistently continuing the success story of maincubes and reinforcing our commitment to sustainable, energy efficient and resilient digital infrastructure.
Michael Booth, CEO of JSM Group, commented:
This project highlights JSM Group’s capability to deliver complex, high voltage energy infrastructure for mission critical environments. Data centres of this scale demand absolute reliability, technical excellence and close collaboration with our partners. We are proud to be playing a central role in enabling maincubes’ expansion in the Berlin region and supporting the delivery of sustainable, high performance digital infrastructure.
Dr. Michael Wiebersinsky, Mayor of the City of Nauen, added:

With the new data centre campus, our region is developing into a highly modern location where future innovations can emerge. From a sustainability perspective, it gives me confidence that Nauen will be a reliable partner for the operating company maincubes.

Hanjo During, Managing Director of E.DIS Netz, said:
With the campus currently under development, we will connect a particularly high performance data centre to our regional electricity distribution network. With the campus planned here in Nauen, the connected capacity will increase significantly in the future.
With the Nauen development, maincubes continues to expand its presence in the capital region, building on the successful operation of its first Berlin data centre, BER01.

Welcome to our new ‘Bytesized’ series, your go-to for a quick read on hot topics in utility infrastructure. Each article delivers insights to keep you informed, fast.

Survey work was recently carried out at a substation in Lincolnshire, where the team undertook a PAS 128 utility survey to support the development of a new cable route for the client. GPS devices were used to capture mark-ups across the site, and the data collected is being processed into a 2D format to visualise the survey findings.

The activities included both utility mapping and topographical surveying. These provided essential information for cable route planning, including land heights, culverts, drains, and their dimensions. This level of detail was key to identifying landmarks and ensuring the proposed route would be practical and efficient.

Utility mapping also played a vital role in understanding existing infrastructure. It helped confirm what was already documented and revealed previously unknown features that may require further investigation. By undertaking these surveys, the team helped de-risk the project, ensuring that design decisions were based on accurate, site-specific data.

The PAS 128 survey provided a critical foundation for the project. By capturing accurate, site-specific data early in the process, we were able to validate existing records, uncover unknown risks, and inform the design with confidence. This proactive approach significantly reduces the likelihood of costly delays later in delivery. – Madalina Cordea, Pre-Construction Project Manager.

This work formed a crucial part of the early planning phase, laying the groundwork for a safe and effective cable installation into the substation.

We’re excited to share that we recently hosted a community engagement event to inform local residents about upcoming essential upgrade works of the existing gas mains and services in the area (Gas Upgrade 037).

The event was a great opportunity to connect with the community, answer questions, and provide important information on how these upgrades will enhance safety and service reliability for everyone.

At JSM Group Services Ltd. we’re committed to keeping the community informed every step of the way. We understand that these upgrades are crucial, and we’re working hard to minimise disruption and ensure smooth progress.

A huge thank you to everyone who joined us – your feedback and engagement are invaluable!

The customer event for our works in the local area was a great success. We were delighted to meet with more than 120 people in the two sessions spread throughout the day.

said Michael Pierce, Operations Manager, JSM Group Services Ltd.

Stay tuned for more updates as we move forward with these important works. If you have any questions or want to learn more, feel free to reach out!

At JSM Group, we pride ourselves on delivering complex infrastructure projects while prioritising environmental stewardship.

Our recent 132kV cable crossing project – connecting to a National Grid substation – tested this commitment with unique challenges that required innovative solutions.

The challenge: Balancing infrastructure needs with environmental protection

The project required an open cut crossing of the main River Colne, which is an ecologically sensitive area and a location where two rivers meet. After extensive planning, we ruled out:

  • Bridge-mounted solutions– due to structural limitations identified by local authorities
  • Horizontal directional drilling (HDD)– engineering difficulties made this approach unfavourable

This left an open-cut river crossing as the preferred option – a method with higher environmental risks that demanded meticulous planning.

Ecological and environmental controls included

Ecological surveys including Phase 1 habitat surveys, water vole surveys and ground level assessments for bat roosts in trees were undertaken.

A check for otters was made prior to the start of works, with one trail camera in place for two weeks. Immediately prior to works, a further check of the banks and the island was made to ensure otters were not present in the area.

Site lighting was avoided overnight, as light can be detrimental to foraging and commuting bats which are highly likely to use the river.

Vegetation clearance (there was minimal required) was undertaken under ecological supervision.

Prior to dewatering, approximately 70 fish, including Bullheads and Perch, were moved safely over the dam.

Good practices regarding preventing pollution were always maintained, including:

  • Fueling vehicles and equipment away from the river
  • Ensuring machinery and equipment were well-maintained to minimise the chance of leaks
  • Having biosecurity measures in place throughout the works

The bigger picture

This 21-day operation – the culmination of 2 years of design, permitting, and stakeholder coordination – underscores how infrastructure development and environmental protection can coexist.

By documenting these lessons, we’re not just improving our processes but contributing to industry-wide best practices.

Joe Scanlon, Head of Civil Operations at JSM says;

Considering the increasing engineering challenges associated with cable routes in the UK, this achievement highlights JSM Group’s capability to overcome such difficulties and ensure projects are delivered safely and efficiently.

A big thank you goes out to all teams involved.

Data centres are now classified as critical national infrastructure – are we doing enough to get them connected? We’ll be joined by other industry experts to discuss this at our roundtable on 23 April 2025. The modern world’s energy demands are evolving rapidly, driven by the rise of data centres, battery plants, and renewable energy projects. These developments are placing unprecedented pressure on network capacity and grid infrastructure. At the same time, speculative practices, such as “Zombie Projects” where planning approvals for solar farms or grid connections are obtained with no intention of timely implementation, are exacerbating these challenges. Such projects often lead to grid congestion and delay the progress of critical infrastructure. In conjunction with Building Magazine, JSM is hosting a roundtable discussion on 23 April 2025 with other industry experts to explore who are the winners and losers, and will the UK end up with what it needs to meet the climate challenge and demand for digital services (data storage and AI) as well as housing and commercial growth? We will be looking at: Understanding network capacity challenges
  • Highlight the increasing demand for grid connections due to rapid growth in data centres and battery plants, which are pivotal for a digitised and renewable energy future.
  • Discuss the implications of “Zombie Projects,” where planning approvals for solar farms or grid connections are sought as speculative investments rather than active developments.
    • Example: Applications for approvals without a clear timeline for implementation.
    • Impact on grid congestion and delays for critical infrastructure projects.
Identifying and prioritising critical infrastructure
  • Examine the importance of prioritising projects based on clear milestones and timelines.
    • Example: Linking grid connection priority to demonstrated project progress (e.g., secured funding, and planning consents).
  • Explore frameworks for assessing the criticality of infrastructure projects to energy security and societal needs.
    • Example: Data centres as essential for the digital economy; battery plants for energy storage and grid stabilisation.
Policy and regulatory strategies
  • Discuss the role of policy in mitigating “Zombie Projects.”
  • Consider regulatory changes to streamline grid connection processes for projects with proven milestones.
Technological and collaborative solutions
  • Highlight innovative solutions to optimise grid capacity:
    • Grid management technologies and dynamic load balancing.
    • Collaborative approaches between utilities, developers, and governments to improve transparency in grid allocation.
 

JSM Group has been appointed to design and build a new grid connection between Hillfield Lane in Elstree and Blossom Way in Hemel Hempstead.

The work spans over 16.3km in both the carriageway and footpath. Upon completion, the work will facilitate the connection of a new Data Centre in Hemel Hempstead via a new 132/33kV substation. Elstree 400kV substation is the nearest substation that has suitable load capacity to supply the demand for the works.

This will be carried out in two phases, phase one which will be the cable duct installation and phase two which will consist of the excavation of joint bays, cable installation and jointing then reinstatement and site cleared.

This involves the excavation and installation of ducts in various roads with planning liaison between JSM Group and Herts County Council. Due to the nature of the works and the impact on the local infrastructure the route has be planned to minimise the disruption to traffic in the surrounding areas wherever possible, this has included avoiding main roads, working longer hours, working outside schools during the summer break and carrying our 24-hour working at the weekends in specific busy locations to reduce the impact and delay on traffic due to the working week traffic flow.

JSM has installed advance warning signs and carried out letter drops of the streets prior to the works commencing. These letters include contact details for the project manager and site manager specific to each road so residents can personally contact the said individuals with any concerns or requirements that they may have. JSM are contactable 24 hours a day to deal with any on site issues.

The traffic management is carried out by a designated approved company who installs and maintains the traffic management with 24-hour contact numbers displayed on all site’s ready to deal with any out of hours emergencies.

Our in-house experts are working hard with key stakeholders including Hertfordshire County Council to ensure minimum disruption to the Public. As the works progress, we will continue to hold frequent reviews with Hertfordshire County Highways and provide weekly updates to assess suitable changes as the project develops. A project specific web site is available to track weekly progress and planned work.