Grid Connection & Medium Voltage Engineer for Battery Energy Storage Systems (BESS)

In the Customer Solution Planning team, you are responsible for electrical engineering design and grid connections for battery energy storage systems serving commercial, industrial and utility-scale projects. You develop safe, cost-effective solutions that meet approval requirements and support projects from feasibility assessment through grid connection and certification to commissioning. You coordinate technical interfaces between internal teams, grid operators, certification bodies, suppliers and delivery partners.

• Assess grid connection points and connection options at low and medium voltage and, where the project scope requires it, at the interface with high voltage. Lead the technical aspects of grid connection applications, connection concepts and discussions with distribution and transmission system operators, resolving open issues until a firm connection commitment is secured.
• Size and specify transformers, medium voltage switchgear, grid connection substations, cable systems, earthing and lightning protection concepts, and measurement and metering concepts. Prepare or coordinate load flow, short-circuit, selectivity and protection studies, as well as assessments of reactive power, voltage quality, harmonics and feed-in management. Agree protection concepts and settings with grid operators, certifiers and commissioning leads.
• Evaluate system architectures comprising battery containers or racks, power conversion systems (PCS), transformers, energy management systems or power plant controllers (EMS/PPC), auxiliary power supplies, communications and control systems. Consider power and energy sizing, efficiency, degradation, availability, control requirements, redundancy and expandability. Review manufacturer documentation, design changes and implementation concepts for safety, selectivity, grid compliance, operability and cost-effectiveness.
• Prepare technical specifications, single-line diagrams, data sheets, quantity schedules, interface lists and specifications of works. Systematically review bids and technical deviations from BESS, PCS, transformer, switchgear and EPC suppliers, and produce clear contract award recommendations.
• Plan and coordinate plant certification and compliance verification throughout projects, including under VDE-AR-N 4110 or 4120, NELEV and relevant FGW guidelines. Gather supporting documentation, models, component certificates and unit certificates early, and manage deviations and conditions through to completion.
• Support technical clarifications during detailed design and construction, attend factory acceptance tests (FAT), site acceptance tests (SAT), and protection, communication and functional tests, and contribute to commissioning declarations and evidence for the grid operator. Coordinate interfaces between batteries, PCS, EMS/PPC, grid connections, fire protection, construction and operations. Clearly document assumptions, risks, dependencies and decisions, ensure complete handovers to Project Management, Construction, Commissioning and Operations, and turn project findings into standards and reusable design solutions.

• You have a degree in electrical engineering, energy engineering or automation engineering, or a comparable qualification with relevant professional experience.
• Ideally, you have at least five years of experience in grid connections, medium voltage, energy installations or BESS projects. What matters is your ability to take independent technical responsibility for complex grid connection and system issues.
• You are familiar with grid connection procedures, medium voltage and protection engineering, as well as connection and certification processes.
• You understand how battery technology, PCS, EMS/PPC, transformers, switchgear, protection and control systems work together. Knowledge of grid services, active and reactive power control, black start or island grid applications is an advantage.
• You can confidently read, create and review single-line diagrams, protection concepts, technical specifications and manufacturer documentation.
• You have experience working with grid operators, certification bodies, specialist designers, suppliers and EPC partners. You can turn technical requirements into clear work packages, review comments and decisions, and assess solutions for safe operation, maintainability, compliance documentation and long-term availability, alongside function and cost.
• You work in a structured and independent way, prioritise technical risks and consistently follow open issues through to a reliable resolution.
• You critically examine assumptions, identify conflicts between grid requirements, supply availability, costs and schedules, and develop practical solutions that meet applicable standards.
• You explain complex technical matters clearly to sales teams, customers, project managers, grid operators, certifiers and suppliers, tailoring your communication to the audience and helping them make decisions.
• You actively share knowledge within the Planning team and improve templates, review criteria and standard architectures to deliver scalable BESS projects with consistently high quality. You are willing to travel for project site visits, supplier visits, grid operator meetings and commissioning within Germany and, when needed, elsewhere in Europe. A category B driving licence is an advantage.
• You are familiar with VDE-AR-N 4110 and the technical connection conditions and application rules (TAB/TAR). Knowledge of VDE-AR-N 4105 and VDE-AR-N 4120, the German regulation on demonstrating electrical characteristics (NELEV), and relevant guidelines from the Federation of Windpower and Other Decentralised Energies (FGW) is an advantage.
• Experience using CAD systems is helpful. Experience with grid calculation software such as DIgSILENT PowerFactory, ETAP or comparable tools is an advantage.
• The role's technical foundations include battery containers or racks, PCS, EMS/PPC, transformers, medium voltage switchgear, grid connection substations, and protection, communication and control systems.
• German at C1 level or above.
• English at B2 level or above; you can also confidently handle technical discussions and documentation in English.