Battery Energy Storage Systems (BESS)
Powering the Future Grid Safely, Reliably and Responsibly
Battery Energy Storage Systems (BESS) are transforming the way electricity is managed, stored, and delivered. As renewable generation increases, large-scale battery installations are becoming essential to balance the grid, stabilise voltage, and relieve network congestion.
At Reynard, we help developers, EPCs, and cable manufacturers connect these systems safely – from design to commissioning.
Why BESS Matters
Across Europe, grid operators like TenneT recognise that large BESS projects are key to maintaining system stability. They enable:
Balancing services to compensate for fluctuations in wind and solar production
Voltage support and black start capabilities for grid reliability
Congestion management by storing energy where the grid is constrained
However, batteries must not worsen congestion or destabilise the system. That’s where precise engineering and reliable cable terminations make all the difference.
Reynard’s Role in Battery Energy Storage Systems
Reynard brings decades of experience from offshore wind to onshore battery integration.
We deliver high-voltage engineering, termination, and testing that ensure every connection performs flawlessly under all conditions.
Our services include:
- Detailed engineering for HV, MV, and LV cabling systems
- Termination and jointing of 33–66 kV connections
- Resonance and VLF testing up to 66 kV
- Commissioning and certification according to IEC 60840 / 62067 standards
- Integration of 400 V auxiliary systems and grounding networks
Each system we work on is tested for reliability, predictability, and full compliance with grid operator standards.
System Readiness from the Start
Every project we support starts with one question: What could go wrong if this connection fails?
That mindset — called System Readiness Thinking — prevents costly omissions such as missing point-on-wave switching, improper bonding, or underestimated inrush currents.
By anticipating these issues early, Reynard helps partners deliver projects that pass testing the first time and remain stable for decades.
Learn more
Why Choose Reynard
- Proven expertise in offshore-grade reliability for onshore systems
- Independent resonance testing equipment (66 kV) available for field validation
- Integrated BoP execution: engineering, installation, and testing under one roof
- Trusted by leading EPCs, cable manufacturers, and renewable-energy developers
Reynard High Voltage Solutions connects the energy transition, one tested connection at a time.
Your Partner in Battery Energy Storage Systems
Choosing Reynard means choosing excellence. I’m not just connecting turbines to cables. I’m connecting the future – homes, cars, all to renewable energy. Let’s make it happen, together.
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Frequently asked questions
▶ What is a Battery Energy Storage System (BESS)?
A Battery Energy Storage System is a large-scale installation that stores electrical energy in batteries and releases it when needed. BESS facilities help balance the grid by compensating for fluctuations in renewable energy production, providing voltage support, and managing network congestion. These systems are essential for integrating wind and solar power into modern electricity grids.
▶ What services does Reynard provide for BESS projects?
Reynard delivers complete high-voltage engineering solutions for battery storage systems, including detailed engineering for HV, MV, and LV cabling, termination and jointing of 33–66 kV connections, resonance and VLF testing up to 66 kV, commissioning and certification to IEC standards, and integration of auxiliary systems and grounding networks.
▶ Why is high-voltage cable termination critical for BESS?
Reliable cable terminations ensure that battery storage systems connect safely to the grid without causing congestion or instability. Poor connections can lead to system failures, voltage fluctuations, or project delays. Reynard’s offshore-grade engineering ensures every connection performs flawlessly under all operating conditions.
▶ What voltage levels does Reynard work with for BESS installations?
Reynard specializes in medium to high voltage connections, typically ranging from 33 kV to 66 kV for grid integration, along with MV and LV cabling systems and 400 V auxiliary networks. We also provide independent resonance testing equipment rated up to 66 kV for field validation.
▶ What is System Readiness Thinking?
System Readiness Thinking is Reynard’s proactive approach that starts every project by asking: “What could go wrong if this connection fails?” This methodology prevents costly issues like missing point-on-wave switching, improper bonding, or underestimated inrush currents, helping projects pass testing the first time and remain stable for decades.
▶ What testing and certification standards does Reynard follow?
All BESS installations are commissioned and certified according to IEC 60840 and IEC 62067 standards. We perform comprehensive resonance and VLF testing to verify insulation integrity and ensure full compliance with grid operator specifications before energization.
▶ Can Reynard support BESS projects from design through commissioning?
Yes. Reynard provides integrated Balance of Plant (BoP) execution, covering engineering, installation, testing, and commissioning under one roof. This end-to-end approach ensures seamless project delivery and eliminates coordination issues between multiple contractors.
▶ Who are Reynard’s typical BESS clients?
We work with renewable energy developers, EPC contractors, cable manufacturers, and grid operators across Europe who require reliable high-voltage connections for large-scale battery storage installations.
▶ How do I get started with Reynard for my BESS project?
Contact Reynard High Voltage Solutions to discuss your battery storage project requirements. Our team will assess your technical specifications, grid connection needs, and project timeline to develop a tailored engineering and testing solution.
