ENMAX Executive and Leadership Team

May, 2026

Leadership Overview

ENMAX has 10 executives leading key functions including strategy, information technology, finance, human resources, operations, and legal.

Driven by a commitment to reliable energy, ENMAX powers the lives of Calgary residents through electricity generation, transmission, and distribution, fostering a sustainable energy future for Alberta.

Leadership Roles at ENMAX

  • President & Chief Executive Officer - Ken Bosma
  • President & Chief Executive Officer - Mark Poweska
  • President & Chief Executive Officer - Masaki Saikusa
  • Chief of Staff & Chief Executive Officer, Office of - Melissa Halderman
  • Chief Financial Officer & Executive VP, Enmax Energy - Sheri Primrose
  • President - Demtri Ontisa
  • President - Edwin Suazo
  • Chief Information Officer - Tony Rizzuti
  • Executive Vice President & Chief Human Resources Officer - Patricia MacDonald
  • Senior Vice President, Regulatory and Chief Legal Officer - Sarah Stevens
  • Ken Bosma - President & Chief Executive Officer

    Ken Bosma, the President & Chief Executive Officer at ENMAX, directs the overall strategic vision and operational execution for the utility company. Overseeing all facets of the business, Bosma ensures ENMAX effectively generates, transmits, and distributes electricity to Calgary residents. This leadership role involves navigating complex regulatory environments and driving innovation in energy services. By fostering strong relationships with stakeholders and the community, Ken Bosma champions ENMAX's commitment to reliability and sustainability. The executive's focus remains on enhancing operational efficiency and expanding service capabilities to meet the evolving energy needs of Alberta.

    Mark Poweska - President & Chief Executive Officer

    Mark Poweska, the President & Chief Executive Officer at ENMAX, guides the company's strategic direction and operational performance. Poweska oversees the comprehensive management of electricity generation, transmission, and distribution services for Calgary and surrounding areas. This executive leadership position involves ensuring the reliable delivery of energy while pursuing advancements in sustainable practices. Mark Poweska drives initiatives aimed at improving infrastructure and customer service, aligning operations with ENMAX's mission. The executive's responsibilities include fostering a culture of safety and efficiency across all departments, solidifying ENMAX's role as a vital energy provider.

    Masaki Saikusa - President & Chief Executive Officer

    Masaki Saikusa, the President & Chief Executive Officer at ENMAX, leads the organization's strategic planning and day-to-day operations. Saikusa is responsible for the end-to-end management of electricity generation, transmission, and distribution, serving the Calgary region. This critical role involves ensuring the consistent and safe delivery of power while championing ENMAX's dedication to environmental responsibility. Through strategic oversight, Masaki Saikusa drives initiatives that enhance operational resilience and customer satisfaction. The executive's mandate includes fostering innovation within the energy sector and maintaining ENMAX's position as a trusted utility provider.

    Melissa Halderman - Chief of Staff & Chief Executive Officer, Office of

    Melissa Halderman, the Chief of Staff & Chief Executive Officer, Office of at ENMAX, provides strategic support and operational coordination for executive leadership. Halderman facilitates the efficient functioning of the CEO's office, managing key initiatives and ensuring alignment across departments involved in electricity generation, transmission, and distribution. This executive role is pivotal in streamlining communication and driving strategic priorities for ENMAX. By overseeing critical projects and advising senior management, Melissa Halderman enhances organizational effectiveness. The executive's responsibilities include optimizing workflows and supporting the execution of ENMAX's broader business objectives for the Calgary area.
    Melissa Halderman

    Sheri Primrose - Chief Financial Officer & Executive VP, Enmax Energy

    Sheri Primrose, the Chief Financial Officer & Executive VP, Enmax Energy at ENMAX, manages the company's financial health and strategic fiscal planning. Primrose oversees all financial operations, including budgeting, forecasting, and investment strategies, directly supporting ENMAX's electricity generation, transmission, and distribution activities. This executive role is vital for ensuring financial stability and driving profitable growth within the energy sector. By providing critical financial insights, Sheri Primrose guides resource allocation and risk management. The executive's responsibilities extend to optimizing financial performance and supporting ENMAX's long-term sustainability goals for the Calgary region.
    Sheri Primrose

    Demtri Ontisa - President

    Demtri Ontisa, the President at ENMAX, directs specific operational divisions and strategic initiatives within the energy utility. Ontisa oversees key functions related to the company's core business of electricity generation, transmission, and distribution, ensuring efficient service delivery to residents. This leadership role involves driving performance improvements and fostering innovation across managed departments. By focusing on operational excellence, Demtri Ontisa contributes to ENMAX's reliability and customer satisfaction goals. The executive's mandate includes managing resources effectively and supporting the company's commitment to sustainable energy practices in Alberta.

    Edwin Suazo - President

    Edwin Suazo, the President at ENMAX, drives strategic execution and operational oversight for designated business units. Suazo manages critical aspects of the company's electricity generation, transmission, and distribution services, ensuring high standards of performance and reliability for Calgary customers. This executive role focuses on optimizing operational efficiency and implementing forward-thinking strategies within the energy sector. By leading key teams and projects, Edwin Suazo contributes significantly to ENMAX's mission. The executive's leadership is instrumental in advancing the company's goals for sustainable energy solutions and continued service excellence.

    Tony Rizzuti - Chief Information Officer

    Tony Rizzuti, the Chief Information Officer at ENMAX, directs the company's technology strategy and digital infrastructure. Rizzuti oversees the implementation and management of IT systems that support electricity generation, transmission, and distribution operations for Calgary residents. This leadership function is crucial for ensuring data security, operational efficiency, and the seamless integration of new technologies. By architecting robust IT solutions, Tony Rizzuti enables ENMAX to enhance its service delivery and maintain a competitive edge in the energy sector. The executive's focus includes driving digital transformation initiatives that align with ENMAX's commitment to innovation and reliability.
    Tony Rizzuti

    Patricia MacDonald - Executive Vice President & Chief Human Resources Officer

    Patricia MacDonald, the Executive Vice President & Chief Human Resources Officer at ENMAX, leads the company's human capital strategy and organizational development. MacDonald oversees all aspects of HR, including talent acquisition, employee relations, compensation, and benefits, supporting the workforce engaged in electricity generation, transmission, and distribution. This executive position is fundamental to cultivating a skilled and motivated team that uphns ENMAX's operational excellence. By championing employee engagement and fostering a positive work environment, Patricia MacDonald ensures ENMAX attracts and retains top talent. The executive's efforts are critical for aligning human resources with the company's strategic objectives and service commitments.
    Sarah Stevens, the Senior Vice President, Regulatory and Chief Legal Officer at ENMAX, leads the company's legal affairs and regulatory compliance strategies. Stevens oversees all legal matters, including corporate governance, litigation, and contract negotiation, while also managing regulatory relationships critical to electricity generation, transmission, and distribution. This executive position ensures ENMAX operates within legal frameworks and adheres to industry regulations. By providing expert legal counsel and strategic regulatory guidance, Sarah Stevens safeguards the company's interests. The executive's responsibilities are essential for maintaining ENMAX's license to operate and its commitment to ethical business practices.

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    Frequently Asked Questions Regarding ENMAX Top Executives and Leadership Team

    Who leads ENMAX?
    ENMAX is led by Ken Bosma (President & Chief Executive Officer), along with executives such as Mark Poweska (President & Chief Executive Officer) and Masaki Saikusa (President & Chief Executive Officer).
    Who is part of ENMAX’s executive team?
    The executive team of ENMAX includes leaders such as Ken Bosma (President & Chief Executive Officer), Mark Poweska (President & Chief Executive Officer), Masaki Saikusa (President & Chief Executive Officer) and other senior executives.
    How many executives does ENMAX have?
    ENMAX has 10 executives leading key business areas.
    What roles are included in ENMAX’s leadership team?
    The leadership team of ENMAX includes roles such as President & Chief Executive Officer, President & Chief Executive Officer, President & Chief Executive Officer, Chief of Staff & Chief Executive Officer, Office of, Chief Financial Officer & Executive VP, Enmax Energy.