Operative entities

ENGineering services in renewables

Leading European engineering and service company in connecting financial and energy markets. Utility-scale planning of renewable technologies, active along all mainstream renewable technologies.

Operative entities

ADVISORY services in renewables

Leading European advisory company enabling customers with services in the areas of M&A, PPA arrangements, due diligence, feasibility studies, ESG and Net-Zero strategies for corporate clients.

Operative entities


Planning and engineering of hi-tech building integrated systems from financing to implementation.

Operative entities

management of agrisolar systems

RSM Energy is engaged in innovative projects of pilot character in the emerging European AgriSolar market.

Operative entities

operations and maintenance for renewable assets

Re-Tec is taking account on the operations servicing of wind and PV assets including inspection, control, engineering and certification.

Operative entities

alpine solar projects

Mountain Sun Technologies assists Alpine Project developers with engineering, technology selection, and project management towards a successful Solar-Express motivated implementation.

Operative entities


Solar Modules: For over 20 years, AE Solar has been a holding production partner at ownership level. Trough AE's listing as a Bloomberg BNEF Tier 1 production company, we are independent of third-party producers.

Operative entities

OE/wind: Development

Wind Project Development: As part of OE-EN, OE/WIND aims to develop commercial generation facilities in the field of eolic renewable energy.


Enabling innovative technology that works, OE-EN's companies operate from technology, advisory, and development to connection to the grid and impact investment – all under one roof: oe.energy.

OE-EN is an umbrella company with the purpose to control investment projects, to participate in innovative technology projects and to build and hold generation plants in the field of renewable energies. It holds investment, technology and operating companies to ensure sustainable development along the value chain of the investments.

from technology to finance in renewables

We enable our partners and customers leveraging the synergies between our companies vertically and horizontally integrated along the entire value chain.

Our enterprises complete the services chain from utility scale projects to industrial and commercial applications. With over two decades of sector experience, we work at the forefront of the competence areas of innovation, financing, M&A, engineering and technical advisory.

services & solutions

We move thousands of megawatts in our partners' projects and monitor billions of euros in renewable power plant investments.

We operate various companies in the area of ​​cleantech and associated services at home and abroad to promote the expansion of renewable energies. Our teams ensure a high level of solution expertise.

Projects & Development

Our dedicated, technology and country-specific project development teams for our international partners and clients.

Together with our clients and partners, we overtake the project development from early stage. We focus on achieving bankable, economically viable, and green cleantech projects of utility scale across Europe.

A playful illustration of our activities along renewable energy. From research and education to PV modules, utility-scale energy projects, asset management, impact investment, alpine solar, agrivoltaic, and commercial buildings.