Executive Team

Character. Experience. Results.

Michael T. Steffes, President & Chief Executive Officer

Our primary focus is to help our Members and Customers manage their energy cost and risk more efficiently. We continually anticipate what risks they will encounter, and collaborate with them to effectively manage those risks.

Mr. Steffes assumed his role as President & Chief Executive Officer of ACES in September of 2013. As Senior Vice President & Chief Operating Officer at ACES for the previous 14 years, Mr. Steffes has been responsible for all commercial activities of the company.  This encompasses managing the company’s areas of Marketing, Origination, Trading, Structuring, Fuels, and Emissions.  Mr. Steffes offers customers a unique level of management experience in energy trading, having held similar executive positions with Pennsylvania Power & Light, Valero Energy and Hadson Gas Systems.

During 2010, Mr. Steffes was interim chief operating officer at East Kentucky Power Cooperative (EKPC) in Winchester, KY, heading up Production, Transmission, Operations and Planning activities.  On assignment from ACES Mr. Steffes was a significant contributor to the successful transition of EKPC during a challenging financial period.

As Vice President of Marketing and Trading for PP&L in Allentown, Pennsylvania, Mr. Steffes led the development of the utility’s unregulated trading subsidiary into a profitable, full-service trading organization.

At Valero Energy, Mr. Steffes helped to pioneer state of the art risk management systems that provided portfolio valuation and calculated value at risk, which helped maximize profitability and managed the risk of Valero’s energy business.

At Hadson Gas, Mr. Steffes led one of the country’s leading natural gas marketing and trading businesses with a large physical and financial presence in the West Coast, Mid-continent, East Coast and Gulf Coast Regions.

In addition to his many years of hands-on energy trading experience, Mr. Steffes holds a Master of Business Administration degree from the University of Detroit.

David H. Claspell, Senior Vice President & Chief Financial Officer

We devote significant resources at ACES to analyzing and verifying energy market settlements statements and invoices, one of the many activities for which I am responsible. We have developed detailed processes that ensure that our Members' and Customers' energy transactions are financially settled accurately.

Mr. Claspell leads the Back Office function at ACES.  His responsibilities include oversight of all energy market settlement activities for ACES’ Clients, as well as oversight of ACES’ internal accounting activities, legal support, human resources, and general administrative functions.

Mr. Claspell has more than 30 years experience in finance, accounting, taxes, and insurance, primarily in the wholesale energy industry. He began his career in public accounting and moved into corporate accounting in the tax department at AMAX Coal Company.  He then spent 15 years as financial advisor and controller for one of the nation’s leading generation and transmission cooperatives (G&Ts) before joining ACES.

Mr. Claspell understands and appreciates the diverse financial requirements of both the G&Ts and their member distribution systems.

He holds a Bachelor of Science degree in accounting from Indiana State University, and is a Certified Public Accountant.

Jeffrey L. Walker, Senior Vice President & Chief Risk Officer

Because there are so many inherent risks in an energy supply portfolio, and because market conditions can change so quickly, Energy Risk Management is a never-ending process. It’s like the advice you give a batter at the plate – never take your eye off the ball.

Mr. Walker leads the Middle Office function at ACES.  The Middle Office has a primary focus on tracking and mitigating risk, as well as risk reporting, and risk management training and consulting.  Mr. Walker’s responsibilities include oversight of all Trading Control, Credit Services, Contract Administration, Regulatory, and Corporate Development functions.

Mr. Walker has been in the energy industry throughout his career with experience in the areas of risk management, trading control, credit, contract administration, finance, power supply planning, financial planning, and accounting.  As a CPA, Mr. Walker served as Controller and then Planning & Finance Manager for one of the nation’s largest cooperative power suppliers.

Mr. Walker joined ACES in February of 1999, and led the design and development of its risk management capabilities to address the wide range of risks facing today’s energy suppliers.

In addition to being a CPA, Mr. Walker holds a Bachelor of Science Degree in Accounting from Indiana University.  Mr. Walker was a member of the Committee of Chief Risk Officers (CCRO), representing ACES from mid-2002 to March 2009, and served as a Director on the CCRO’s Board from October 2003 to March 2009.

Mr. Walker’s years of energy supply experience, combined with his expertise in finance and risk control, give him a unique perspective on the risk management needs of energy suppliers.

Chris Haas, Senior Vice President & Chief Information Officer

The mission for our technology team is for it to deliver the highest level of service possible to staff, Members, and Customers, to protect ACES’ business information technologies, and to demonstrate technology leadership and innovation that furthers our mission. Managing change, fostering innovation, providing exceptional financial stewardship, while delivering excellent service to our Members and Customers is essential to the success of our organization.

As part of the ACES Senior Management team, Mr. Haas is responsible for leading the IT organization at ACES.  Prior to becoming CIO in January 2018, Mr. Haas held a variety of IT positions over his 18 year tenure at ACES. Prior to joining the ACES team, Mr. Haas held positions with International Paper, G.D. Searle, Profound Consulting, and Wabash Valley Power Association.

In leading the ACES IT organization, Mr. Haas and his team are responsible for implementation and 24 x 7 support of ACES’ trading, risk, analytical, and settlement software solutions; maintaining, enhancing, and supporting a robust and reliable telecommunications and network infrastructure; designing and implementing best practice controls designed to meet regulatory and financial reporting requirements; developing and managing physical and cyber security programs; and leading business continuity and disaster recovery planning and readiness for ACES’ four regional trading centers and the national service center.

Mr. Haas has experience leading large-scale system implementations, managing vendor relationships, building key technology partnerships, directing enterprise architecture design, managing ACES Member and Customer integration and consulting efforts, and supporting the planning and establishment of ACES’ technical vision.  Mr. Haas has successfully led numerous strategic, multi-million dollar implementations including SAP enterprise resource planning system integration projects, customer relationship management solutions, commodity trading and risk management systems, and ISO bid to bill solutions.

Mr. Haas has a proven record of operational excellence, financial stewardship, customer service, leadership, and innovation.  He has an extensive knowledge of various energy markets and the services ACES provides to its Members and Customers, including forecasting, portfolio optimization, market operations, risk management, settlements, energy allocation, and invoicing.

Mr. Haas holds a Bachelor’s degree in Computer Technology from Purdue University and is an active member of the National Society for Information Management.

H. Annette Stamatkin, Senior Vice President & Corporate Project Officer

Cyber security and mobile initiatives are driving ACES’ IT strategies. Providing information-based solutions in a fortified environment is our number one priority.

Ms. Stamatkin leads the Information Technology function at ACES. Ms. Stamatkin joined ACES in June 2000, having held previous executive positions with Wabash Valley Power Association and North Carolina Electric Membership Corporation (NCEMC). Ms. Stamatkin has successfully led numerous strategic, multi-million dollar implementation projects including corporate financial and wholesale billing systems, customer information systems and call centers, commodity trading and risk management systems (CTRM), energy management systems, and Supervisory Control and Data Acquisition (SCADA)  throughout her career.

Ms. Stamatkin’s current responsibilities include overseeing the implementation and 24×7 support of ACES’ real-time trading, financial and analytical systems, websites and data warehousing solutions including a multi-commodity CTRM, multiple ISO/RTO trading and settlements systems, analytical and data warehousing tools, corporate financials, telecommunications including local and wide area networks (LAN and WAN), and real-time connectivity to Members’ and Customers’ EMS and SCADA systems.  Ms. Stamatkin is also responsible for business continuity planning and readiness for ACES’ four trading centers: National Service Center in Carmel, IN, and Regional Trading Centers in Raleigh, NC; Maple Grove, MN; and Benson, AZ.  
Ms. Stamatkin brings over 25 years of information technology and energy industry experience to ACES. She has managed the deployment and support of energy trading and real-time operational systems, national telecommunications solutions for deregulated retail and wholesale power markets, and multi-commodity trading and risk management for Generation and Transmission cooperatives.

Ms. Stamatkin earned a Bachelor of Computer Science degree from the School of Engineering at Purdue University, and is a graduate of the University of Michigan’s Executive Public Utility Management Program.