Diem Consulting GmbH


About us

Diem Consulting was founded in April 2016. Our consultants are industry experts with many years of experience in management and in the energy industry.

Through our operational experience, we have gained a deep knowledge of regulated processes and relevant regulatory frameworks. Project management experience from numerous projects allows us to take a higher level view without losing the sometimes tricky details. This makes us a trustworthy and competent contact for all hierarchy levels.

Marianne Diem, CFA

Marianne Diem

Marianne Diem, Dipl. math., CFA
Managing Director and Owner
telephon: +49 151 67325609
email: marianne.diem@diem-consulting.de


Marianne Diem has 15 years of experience in the energy industry.


After starting her carear in the banking sector, she worked as a quantitative analyst and risk manager with several energy suppliers. Later, as Head of Risk Management at Stadtwerke Leipzig, she was leading a team of 11 employees, responsible for everyday risk monitoring of energy trading, negotiation of master agreements for trading activities, credit line control, entry into new markets and marketplaces, implementation of regulatory requirements from REMIT and EMIR, development of quantitive methods for valuation and risk quantification and optimization of power plant dispatch.


Since April 2015, she has been working as a consultant, initially as head of the Berlin office of Scherbeck Energy, since April 2016 as Managing Director of Diem Consulting GmbH.

Michael Rösner, PHD

Michael Roesner

Michael Rösner, Dipl. Kfm, PhD
Senior Manager Finance, Controlling, Renewable Energy
telephon: +49 172 364 8030
email: michael.roesner@diem-consulting.de


Dr. Michael Rösner has 15 years of experience in the energy industry.


He gained his distinctive experience as a managing director of Clean Energy Sourcing GmbH, which he developed from a startup to the leading renewables marketer. He also has several years of consulting experience as a managing consultant at Capgemini Consulting.


As an expert on renewables, his expertise lies particularly in the areas of energy markets and marketing of renewables.


Dr. Michael Rösner holds a PHD and a master of business administration of the University of Chemnitz.

Our Competence

Whether it is process optimization, project management support, quantitative analysis or expert opinions,
Diem Consulting supports energy suppliers and energy-intensive companies in particular in the areas of:

  • Energy Procurement & Energy Trading
  • Energy distribution
  • Pricing, Risk Management & IT
  • Controlling & Finance