About us
SONNWINN GmbH is a firm of experts and engineers for photovoltaics and electricity storage, based in Wedel near Hamburg, Germany. We inspect installations, prepare expert reports and provide independent advice.
Who we are
SONNWINN grew out of a network of experts and engineers from the solar industry. In May 2025 we founded SONNWINN GmbH from this network – the heart of the network and your permanent point of contact. From the network, we bring in exactly the expertise your project needs. Our head office is in Wedel near Hamburg; our experts have further locations in Lower Saxony, Hesse and Bavaria. We work throughout Germany and internationally.
We support projects with PV systems and battery storage from planning to operation, including trackers, agri-PV, floating PV and large-scale storage. You have one contact person for all services.
The name comes from Old High German: “sunn” (sun) and “wini” (friend), meaning “friend of the sun”.
Management
Dipl.-Ing. (FH) Marco Wilke
Managing Director, expert in photovoltaics and storage
Engineering physicist, expert in the field of photovoltaics since 2011. Main areas: construction progress monitoring, technical inspections of rooftop and ground-mounted systems and storage systems, yield assessments with PVsyst.
Dipl.-Ing. (FH) Robert Pfatischer
Managing Director, expert in photovoltaics and storage
Electrical engineer; from 1998 to 2020 co-founder, authorised signatory and managing director of meteocontrol GmbH, previously Head of Quality Services. Main area: quality assurance of projects.
Further experts
Dr.-Ing. Stefan Bofinger
Co-founder, expert in photovoltaics
Expert in the field of photovoltaics since 2002, independent consultant for investors and banks. Studied electrical engineering, doctorate on power supply grids with a high share of solar energy.
Mathias Röper, M. Eng.
Co-founder, expert in photovoltaics
Environmental engineering (B. Sc.) and renewable energy systems (M. Eng.), engineer and expert in the field of photovoltaics since 2017. Main areas: glare assessments, preliminary design, special assessments such as ground shading analyses.
Dipl.-Ing. (FH) Christian Binder
Expert, technical programme management for energy management systems
Expert reports, consulting, analysis and commissioning of energy management systems.
Arthur Zlotver
Expert for glare and noise assessment
Lukas Schramm
Expert for glare assessment
Cedric Wilke
Yield assessments
Steen Oppermann
Yield assessments
Emilia Heinzel
Geographic information systems
Adrian Pfatischer
Data preparation and preliminary design
Ani Ostatishvili
Marketing and design, system visualisations
Felix Worm
Back office
Selected references
Besides Germany, our experts have inspected and assessed installations in more than 25 other countries: ground-mounted systems up to 50 MWp and rooftop systems up to 13 MWp, from technical due diligence and construction progress monitoring to end-of-warranty inspections, as well as yield, glare and defect assessments. Since 2021 our experts have prepared more than 1,300 glare assessments and statements in all 16 German federal states.
Services
Technical inspections of PV systems and battery storage, expert reports for planning, permitting and disputes, and planning and consulting.
SONNWINN GmbH
Elbstraße 88/1
22880 Wedel (near Hamburg), Germany
Phone +49 4103 121 4221
Email kontakt@sonnwinn.de
Managing directors: Marco Wilke, Robert Pfatischer
Amtsgericht Pinneberg (local court), HRB 19080 PI
Imprint
Enquiry
Use the form, call us on +49 4103 121 4221 or write to kontakt@sonnwinn.de – whichever suits you best.
You do not need to attach documents to your enquiry – once we have received it, we will help you put together the documents required.