The Role

Are you passionate about energy storage and eager to apply your engineering skills in a fast-growing renewable energy environment? We are looking for a motivated BESS Intern to join our Energy Storage team, supporting the development and operation of Battery Energy Storage System (BESS) assets. Based in Madrid within the wider technical team and reporting to the relevant BESS Manager, this role offers the opportunity to contribute to operational excellence while gaining exposure to project development, construction, commissioning, and asset performance activities.

The BESS Intern will support the analysis and optimization of operating assets, develop tools and insights for BESS operations, and assist with projects under construction. You will collaborate closely with engineering, construction, operations, and commercial stakeholders, contributing to schedule reviews, commissioning activities, contract assessments, and technical design reviews that help ensure the successful delivery and performance of energy storage projects.

Desirable skills

- Electrical Engineering degree or currently pursuing a degree in Electrical Engineering
- Strong analytical skills with the ability to interpret operational and performance data
- Familiarity with project documentation, technical specifications, and engineering drawings
- Exposure to or interest in developing knowledge of Battery Energy Storage Systems (BESS) and power system fundamentals
- Proficient English communication skills, with the ability to collaborate effectively in an international environment
- AI & Digital Literacy: experience using or developing digital tools or workflows to improve efficiency, innovation, and productivity

We deploy AI across the business,



from generation and trading decisions to the everyday workflows of every team. We invest in our people’s digital fluency so everyone works alongside these tools with confidence. Studies show that many qualified candidates hesitate to apply unless they meet every requirement. If this role excites you, but you don’t meet every single qualification, we still encourage you to apply. We value diverse skills, perspectives, and experiences that contribute to a stronger team.

About Us Sonnedix is a integral renewable energy company delivering 100% clean electricity through a diversified portfolio of solar, wind, and storage assets. With almost two decades of sustainable growth, we are committed to Powering a Bright Future, as we continue acquiring, developing, building, and operating renewable energy projects for the long-term, delivering innovative, tailored, and fully renewable energy solutions to our customers.

We help you thrive at work and beyond: A people-first company, committed to offer flexibility, a family-first approach, wellbeing and training support, and – above all – team connection and community!

We are tech-fluent by design: Technology isn’t a support function, it’s how we run. We deploy AI across the business and future-proof your career by investing in our people’s digital fluency.





We have nearly two decades of sustainable growth: Our successful track-record of nearly 2 decades is testament to our strong sustainable growth focus. We are a reliable partner and employer, for the long term!

We are truly diverse and inclusive: A culture of listening to each other, educating ourselves, and implementing changes to improve and ensure every member of our One Team feels and knows they belong.

Hear from some of our team about Sonnedix: https://www.sonnedix.com/careers

What we offer

- One company, many careers - as the company grows, we offer the opportunity for you to develop your career with us
- An inclusive, international working culture with a diverse team of friendly professionals from across the world
- A commitment to flexibility – hybrid working, generous annual leave allocation with an additional four weeks of discretionary unpaid leave
- A family first company - generous paid parental leave and support for carers
- The ability to ‘work from elsewhere’, for up to six weeks in a year
- Summer working hours
- Financial, Social, Mental & Physical wellbeing support
- The Sonnedix Academy – a range of training and development opportunities including professional development, management and leadership programs, technical training, essential skills, DEI, mentorship and much more
- Dedicated learning paths, tools, and resources to help every colleague confidently use AI and digital tools in their work
- Fantastic office environments
- Social events, team building opportunities and One Team Network groups, which are employee-led groups, based on shared identities, interests, backgrounds and life experiences

and many more local benefits!

📌 BESS Intern (Madrid)
🏢 Sonnedix
📍 Madrid