ista International Management

Thomas Zinnöcker

Chief Executive Officer

Thomas Zinnöcker, born 1961, has assumed the role of CEO Group on March 1, 2016. Effective October 1, 2017 he additionally took over the chair of ista Germany’s Supervisory Board. He has significant experience in the German real estate industry, having held a variety of management positions across different firms. As the Deputy CEO of Germany's largest housing company, Vonovia SE, he was last responsible in particular for the successful integration of the GAGFAH Group, where he had previously been the CEO since April 2013. Prior to that, he had headed GSW Immobilien AG for eight years. At ista, Thomas Zinnöcker is responsible for the ista Group including the corporate functions of Communications and Public Affairs, Human Resources, Legal as well as Marketing and Business Development.

Achim Dicke

Chief Technology Officer

Achim Dicke, born in 1964, has been a Chief Technology Officer (CTO) and member of the ista group executive board since July 2018. Previously, he was Senior Vice President of the Products field and has already worked at ista for over 28 years. During his career, the graduate electronics engineer worked in the fields of product management, innovation management, product and service development, as well as procurement & supply chain, for which he is responsible today.

Ulrich Fischer

Managing Director Global & Developing Markets

Ulrich Fischer, born in 1966, is the Managing Director Global & Developing Markets and member of the ista Group board since October 1, 2017. He has valuable experience in the global submetering business, having held several national and international management positions at ista and its predecessors Viterra and Raab Karcher Energy Services. From 2009 to 2011 he was member of the board at Techem Energy Services before he returned to ista.

Ralf Görner

Chief Operating Officer Germany

Ralf Görner was born in the Allgäu in 1964. He studied Business Administration at Regensburg and Mannheim universities. He has been Chief Operating Officer (COO) at ista Deutschland GmbH since 2014. He has many years of experience in the industry. Before joining ista, the business administration graduate worked at Minol for 17 years in various national and international managerial positions. As a member of the Management Board, he was last responsible for finance and organisation and, at an international level, also for IT, process control, customer service and product development.

Frank Jung

Chief Financial Officer Global & Developing Markets

Frank Jung was born in Hilden in 1971. After training as a banker, he graduated in 1998 with an MBA in Business Administration from the University of Cologne. Until 2000, he held various positions in corporate banking, investment banking and corporate development at the Dresdner Bank group. He then worked for six years in M&A consulting at Deloitte. In 2007, he subsequently became a Treasurer & Senior Controller at ista. In 2010, he changed again to become the Head Regional CFO in ista’s international business. From October 2010 onwards, Frank Jung was responsible for the Business Unit Global & Developing Markets together with Ulrich Fischer.

Karl Kornwolf

Chief Information Officer

Karl Kornwolf has been ista's Chief Information Officer since January 1, 2019. In a career spanning more than twenty years, he has built up digital business models and developed products/services. His career began as a business consultant in today's, one of the largest IT services corporations in the world. In various operational management roles, he reorganised a cable TV provider and the IT and innovation division of Deutsche Telekom AG among others. Karl Kornwolf was last responsible for Strategy and Business Development in the Energy division of Siemens. His focuses were the further development of the portfolio for distributed energy systems and integrated IoT business models ("From Hardware to Services") as well as the global transformation of the division. Parallel to this, as a start-up entrepreneur, he established a learning and innovation platform for German small and medium-sized enterprises – with the aim of solving the problem of the global shortage of skilled workers in certain fields.

Thomas Lemper

Chief Financial Officer

Thomas Lemper was previously Senior Vice President Corporate Controlling & Finance. In 2006, he joined ista as Head of Controlling for the Central Region and as part of a posting to the United States he was CFO of the local company. Lemper studied business administration in Münster and gained initial experience in various finance positions at Lufthansa.

Benny Mathiesen

Country Manager Denmark

Benny Mathiesen, born in 1966, is CEO in Denmark, Regional CEO for the Nordic Countries and member of the ista Core Market Board since July 2018. He started his career in the ista Group in 2003 as Director of Clorius Varmemålerkontor I/S in Odense. Clorius Varmemålerkontor I/S is a subsidiary of ista Danmark A/S. Through previous employment in the industrial sector, Benny Mathiesen has gained extensive experience within the energy business.

Jörg Plönissen

Country Manager Netherlands

Jörg Plönissen, born in 1961, is Country Manager for the Netherlands since 2004 and member of the extended Board of the ista Group since 2018. He has valuable experience in ERP solutions and cash management for the utility and retail industry. In 2013, he became Chairman of the NLVVE, the Dutch Association for the submetering market.

Laurent Sireix

Managing Director France

Laurent Sireix, born in 1967, is Managing Director ista France. Since October 1, 2017 he is also a member of the ista Group board. He has broad experience in the energy industry having held several managing positions: e.g. he was Managing Director of Gaz France at Schlumberger. He joined ista France in 2004 as Director of Operations and then became Managing Director ista France in 2005.