About Us

We help you to grow your clean technology and renewable energy business


We are a global team of Commercial and Investment Bankers, CPAs, Tax Specialists, Lawyers and Engineers

As an independent corporate development and corporate finance advisory firm, CleanTech Capital has formed a small but very experienced and effective core team that will be supplemented by highly qualified experts from different areas.

CleanTech Capital has a strong network of advisors, entrepreneurs and investors throughout Europe, North America, South America, the Middle East and Asia and cooperates with leading law firms, accounting firms and financial institutions around the world.

Matthias Retter


Matthias dedicated his career to environmental finance and water where he has gained over 12 years of experience in investment management, management consulting, engineering and research. He is recognized by value adding assignments to institutional investors, banks, export credit agencies, corporates and the private and public sectors. He previously had been a global leader of the sustainable water management hub at PricewaterhouseCoopers (PwC), which he built up and managed it for years.

His professional overview earned him invitations for key notes at conferences and UN meetings, but also media reviews from Handelsblatt, FAZ, L’Express France or Les Echos France. Co-contributions to water projects were also awarded by the White House in Washington under president Barack Obama as Top 1 private sector innovator.

In addition, Matthias drives education towards a sustainable world for next generation decision makers by lecturing at the Copenhagen Business School and the Vienna University of Economics and Business.

Tomasz Zmyslowski


Thomas is a trained engineer with extensive technical and management experience in product and market deveopment of sustainable technologies, in particular in energy efficiency and energy storage projects.

Gustavo Weigel

South America

Gustavo Weigel is Head of the South America region for CleanTech Capital. With more than 25 years of international professional experience, he focuses on M&A transactions, business valuation, investment projects and finance structuring. He has been involved in many international transactions between Latin America countries in ports, logistics, agribusiness, renewables, real estate industries, financial, insurance and beverage industries. Gustavo founded his own corporate finance business, Weigel Haller, in 2000. Gustavo worked at accounting firms Coopers & Lybrand and Price Waterhouse and several multinational companies where he held management and board of director positions. Gustavo holds a CPA degree from the University of the Republica Oriental del Uruguay and has completed post-graduated business executive studies in Universidad de Montevideo.

Zuzanna Olender

Energy Management

Zuzanna Olender supports our Polish activities in clean technologies and renewable energy.

Dr. Andreas Schlatter

Industry Optimization

Andreas Schlatter contributes more than 20 years experience in strategy consulting, industry optimization, sustainable management and renewable energies with special focus on the complete photovoltaic value chain. He works as the CTO and as a project manager to set-up several PV production plants for leading companies in Europe, Asia and USA. Andreas used to work in energy, quality and productivity optimization for Holcim AG and Alusuisse-Lonza AG. He holds a PhD in Sustainable Industry Management from the Federal Institute of Technology (ETH), an MBA in Finance and Accounting from University of St.Gall (HSG) and an MSc in Electrical Engineering from ETH. He also teaches Leadership and Organization at the University of St. Gall.

Matti Laakso

Nordic Markets

Dr. Winfried Weigel


Winfried Weigel formed CleanTech Capital (Zug) in 2004. He is an experienced investment banker with a track record of landmark transactions in mergers and acquisitions, capital markets, project finance and credit advisory. He served as Managing Director for UBS in Zurich and Frankfurt, as Executive Director for UBS Warburg in London, and as Vice President for J.P. Morgan Chase in New York and London before starting his own entrepreneurial activities. Winfried holds a PhD in Economics (Capital Markets Theory), a MBA in Business Administration (Majors in Accounting, Tax and Banking), and a LL.M. (Corporate and Capital Markets Law).

Rosana Bomba

Financial Advisory

Rosana Bomba holds a CPA degree from the University of the República Oriental del Uruguay and a post-graduate in Corporate Finance from the Catholic University of Uruguay. She has more than four-teen years of professional experience, previously to joined the Firm she worked for Deloitte. Rosana is highly knowledgeable in M&A deals, company valuations and investment projects development mainly in the logistics and agribusiness sectors.

Geoffrey I. Marney

North America

Geoff Marney joined CleanTech Capital in 2008 and runs our North American office as Managing Director of CleanTech Capital North America. Geoff brings a wealth of experience in international cleantech and green technologies transactions. He brings Wall Street and Bay Street expertise to environmentally focused business owners. After working with leading firms such as NBTel, Aliant Telecom as well as a number of technology joint ventures with Nortel Networks and Bell Canada, Geoff joined an investment banking group based on Bay Street, Toronto and eventually founded Pathpoint Capital Partners. Geoff holds a BSc from DeVry University with a major in operations research and a minor in accounting.

Thomas Goetz

Benelux and Germany

Thomas York Götz brings twenty years of experience working with technology start-ups, family-owned businesses, private equity owned and listed companies. Thomas is an expert in team building and entrepreneurship with a strong marketing and finance background.

Thomas lives in the Netherlands and leads the Benelux and Northern German business development for Weigel Corporate Finance. He also leads the execution of international projects in various industries.

Thomas joined the Weigel Corporate Finance network in 2015 after building up his own advisory business. He brings a strong management track record based on his international assignments for Univar EMEA, Vodafone Libertel B.V., Wunderman and several family-owned businesses, e.g. Nordmann and the Rassman Group, with responsibilities for marketing & sales, change management, financial management and human resources. Thomas’s industry experience comprises telecoms, IT, software, automotives, biotech and the chemical industry.

Over the past years Thomas also worked as a coach and jury member for the European Venture Contest. Thomas is member of the foundation for the promotion of the bio-industry in North-Rhine Westphalia and the association BioRiver – Life-sciences in the Rhineland e.v.

Thomas combines a strong entrepreneurial background from his parent’s family-owned businesses in Southern Germany with an extensive international network. He earned a fully accredited executive MBA from dual program of the Transatlantik Institute in Germany and the University of West Florida and a graduate degree in business at University of Applied Sciences in Ludwigshafen.

Matthias Bruck

German speaking and CEE markets

Matthias joined CleanTech Capital in 2012 as external advisor when he started his own private equity investments after his five year tenure as Director for Business Development at the Austrian Business Agency where he was responsible for Switzerland, France, Benelux and Scandinavia.

Matthias covers Austria and central and eastern European markets and brings in a wealth of experience in electric mobility, energy efficiency, renewable energy, “startup business issues” and “old economy” He is also member of the Board and shareholder in various clean technology companies.

Before joining the Austrian Business Agency Matthias held different executive management positions in the pulp and paper and the telecoms industry in Austria, Russia and Central and Eastern Europe and is still serving on the board of the European Data Security Institute since 2002.

Matthias graduated from the University of Illinois (USA) and holds a Magister Degree from the University of Vienna. He also lived in Taiwan and visited Cheng Chi University in Taipei as a foreign exchange student. After two years with KPMG in Vienna he joined an international M&A advisory boutique in London where he was responsible for the origination and execution of cross-border M&A transactions with a focus on central and eastern Europe including the CIS.

Will this be you?

If interested, please email your CV to: my.job@cltcap.net
We staff our projects to your needs and we bring in additional industry experts as needed for the project.