Commissioning Engineer – Battery Energy Storage (BESS) UK (Ayrshire - site-based) MDE Group are working with a global leader in renewable energy and energy storage solutions to support the growth of their UK delivery team. We are looking for a Commissioning Engineer with experience in Battery Energy Storage Systems (BESS) to support installation, commissioning, and troubleshooting activities across multiple project sites. Key Responsibilities * Carry out installation and commissioning of battery energy storage systems in line with technical requirements * Perform testing, debugging, and fault finding on BESS equipment (including inverters, PCS, and associated systems) * Support site planning and coordination of commissioning activities * Troubleshoot and resolve system issues to restore performance efficiently * Assist with maintenance and technical upgrades of energy storage systems * Work closely with internal teams and international engineering support functions Requirements * 2 years’ experience in BESS commissioning or similar energy storage projects * Strong background in electrical engineering, HV/LV systems, or power electronics * Experience with on-site commissioning, testing, and fault finding * Relevant certifications such as CSCS, IOSH, NEBOSH, SMSTS, or equivalent * HV/LV authorisation or electrical qualifications highly desirable * Strong communication skills and ability to work in a site-based, hands-on environment * Proficient in standard office/software tools * Willingness to travel and work on projects across multiple locations Desirable * Experience working with battery OEMs or inverter systems * Exposure to international teams or projects What’s on Offer * Opportunity to work on cutting-edge energy storage projects * Join a fast-growing sector at the forefront of the energy transition * Competitive salary benefits career progression