About Us – BESSr GmbH

BESSr GmbH was founded in 2025 and stands for modern battery storage solutions with a clear focus on the energy transition. As a young company, we build on a strong foundation of experience: our founding shareholders have been active in wind energy and photovoltaics for more than 20 years.

We combine this know-how with direct access to technology, a strong partner network and genuine implementation expertise. This is how tailor-made storage solutions are created that make renewable energy more efficient, more flexible and more economical to use.

BESSr is young in appearance – and experienced in delivery.

Our Team

Behind BESSr stands a management team with decades of experience in renewable energy, battery storage, international manufacturing and engineering. As entrepreneurs and industry experts, we combine technological expertise, operational excellence and direct access to global manufacturers – for the successful delivery of demanding BESS projects in Europe.

Martin Rosendahl
Chief Executive Officer (CEO) | Shareholder

As Chief Executive Officer, Martin Rosendahl is responsible for the strategic direction and business development of BESSr GmbH. His focus is on developing new business models, building strategic partnerships and advancing the company in the European energy market.

His many years of entrepreneurial activity in wind energy and photovoltaics shape the approach of BESSr GmbH. For many years he has carried out expert assessments of wind turbines and is also active in service, operational management and the development of wind energy projects. In addition, he has extensive experience in the planning, construction and commissioning of rooftop and ground-mounted photovoltaic systems.

Birger Menke
Chief Operating Officer (COO)

As Chief Operating Officer, Birger Menke is responsible for the operational delivery of all BESSr GmbH projects. His remit covers project development, engineering, EPC, project management and the build-up of efficient processes for realising complex battery storage projects.

With his many years of experience in energy and plant construction and in the development and delivery of demanding infrastructure projects, he combines technical expertise with a keen understanding of commercially sound project execution. His focus is on the successful delivery of projects – from the first concept through to commissioning.

Wen Zhang
Managing Director – Asia Operations & Global Supply Chain | Shareholder

As a shareholder, Wen Zhang is responsible for the operational activities in Asia and for the global supply chain of BESSr GmbH. She steers the cooperation with leading battery and component manufacturers, is responsible for international procurement and coordinates the technical alignment with suppliers and production partners.

As an entrepreneur, she has many years of experience in the development and manufacture of innovative ultrasonic welding technologies for electrical components. Her solutions are used in demanding applications in electric mobility, battery storage technology and AI data centres. Through close cooperation with the world’s leading manufacturers in the battery and automotive industries, she has an in-depth technical understanding of high-voltage connection technologies as well as an established network along the international value chain. This expertise forms the basis for direct access to leading technology partners and for a high-performing global supply chain for the projects of BESSr GmbH.

Our Corporate Network

Through close cooperation with our founding and sister companies, we bring together technical expertise, market proximity and many years of experience in the energy industry.

Hysum Technology Co. Ltd.

An innovative company from China specialising in the manufacture of high-quality components – among them particularly low-resistance battery connection cables produced by ultrasonic welding. Its customers include internationally leading battery manufacturers such as CATL and BYD. Through these strong industrial partners, BESSr GmbH benefits from direct access to quality products of the highest technical standard and can select and implement battery storage solutions based on modern and proven technologies.

NEA GmbH

With more than 20 years of experience in the photovoltaic and wind energy industry, NEA GmbH is a proven specialist in the technical operational management of wind turbines, photovoltaic systems and battery storage systems. Its services comprise the continuous monitoring, analysis and optimisation of the installations, the coordination of service and maintenance measures as well as comprehensive technical consulting. The aim is to minimise downtime, increase plant availability, reduce costs and raise yields sustainably.

As a registered electrical company, NEA GmbH offers further services in the field of renewable energy. These include in particular condition-based repair and generator maintenance of wind turbines (WTGs).

NEA GmbH also supports the delivery of PV and BESS projects and plans grid connections.

In doing so, NEA combines its many years of experience in plant operation with electrical engineering expertise and hands-on implementation experience.

Rosendahl Windtechnik GmbH

With comprehensive experience in the wind energy industry, Rosendahl Windtechnik GmbH is a specialised partner for the technical testing, assessment and inspection of wind turbines. As an inspection body accredited to DIN EN ISO/IEC 17020, it carries out recurring inspections, lifetime extension assessments and technical condition evaluations. Through sound expertise, hands-on knowledge of the installations and independent inspection services, Rosendahl Windtechnik helps to increase operational safety, minimise risks and secure the reliable continued operation of wind turbines.

Together, this network offers a complete portfolio of services – from the selection and procurement of market-leading battery storage systems through their implementation to long-term, efficient and reliable operational management.

Our Partners

In addition to the competencies within our immediate corporate environment, we work with selected distribution partners who carry our storage solutions into the market and deliberately widen our access to end customers.