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Executive leadership team

Andrew Bills 

andrew bills

Chief Executive Officer

Andrew Bills commenced as CS Energy’s Chief Executive Officer in October 2018. He has more than 20 years’ experience in the energy and infrastructure industry where he has worked in trading, retail, generation, LPG, solar, and renewables. 

Prior to joining CS Energy, Andrew worked for Origin Energy for nearly a decade in multiple roles with his last as General Manager LPG and Health, Safety and Environment in the Energy Markets Division. In this role Andrew led the LPG arm of the business, a complex task managing the entire supply chain that spans across 75 sites in nine countries, including four joint ventures in the Asia Pacific.

Prior to Origin, Andrew worked at Babcock & Brown Power where he was responsible for managing commercial operations undertaking several acquisitions and managing joint ventures. Before that he was a senior executive at Stanwell Corporation where he managed the trading and marketing functions.

Andrew has served as a director on multiple boards, including as Chairman of Gas Energy Australia, and an Industry Representative on the Advisory Council to the Energy and Water Ombudsman Queensland. He is currently a director on the board of the Australian Energy Council.


Darren Busine 

darren busine

Executive General Manager Revenue Strategy

Darren Busine has more than 25 years’ experience in senior finance roles in the energy and banking sectors. As Executive General Manager Revenue Strategy, Darren’s role is to align CS Energy’s long-term growth strategy with the business’ shorter-term market trading function. Darren is also responsible for the dispatch of the company’s generation portfolio in the NEM, wholesale and retail electricity market contracting strategies, energy market analysis and regulation, and business planning and execution. 

Darren joined CS Energy in 2016, serving as Chief Financial Officer for 12 months before being appointed to the Executive General Manager Revenue Strategy role in 2017. Prior to joining CS Energy, Darren was CFO at QEnergy, an energy retailer based in Queensland but targeting the small to medium size business market across the eastern seaboard of Australia.

Darren was the CFO of Energex from 2007 to 2014. During this time Darren led the finance, legal, company secretariat, and risk and governance teams. Joining Energex after the sale of their retail operations, Darren played a key role in the transformation of the Energex business, including implementing significant improvements to financial management and reporting.

From 2000 to 2007 Darren was with Ergon Energy, initially as Group Finance Manager and then CFO from 2006. Darren was responsible for integrating the finance functions of newly merged distribution entities. He also undertook improvement roles, including the setup of joint venture operations for billing and IT services with Energex.

Prior to his experience in the energy industry, Darren spent 10 years with Suncorp. Darren is a director of the Queensland Music Festival where he serves as Treasurer.


Malcolm Wilson

Malcolm Wilson 

Chief Financial Officer
B.Sc. (Hons), B.Com., FCPA, GAICD, MAusIMM, MIML 

Malcolm Wilson leads CS Energy’s Finance, Energy and Financial Risk, IT, and Procurement functions. He joined CS Energy in 2018 from the Queensland Department of Health where he had been Chief Finance Officer for four years.

Malcolm has held senior financial roles in large, complex and geographically dispersed organisations in Australia and internationally. He has participated in major greenfield and brownfield capital projects, led significant commercial contract negotiations, been prominent in successful Enterprise Resource Planning System implementations and played a key role in corporate funding, off-balance sheet financing, acquisitions and divestments. 

Malcolm holds two degrees from the University of Tasmania – a Bachelor of Science with First Class Honours in Chemistry and a Bachelor of Commerce. He is a Fellow of CPA Australia and a Graduate Member of the Australian Institute of Company Directors.


Leigh Amos 

leigh amos

Executive General Manager Plant Operations
BEngTech, MBA

Leigh Amos commenced as Executive General Manager Plant Operations in 2019. In this role he manages the operational performance of CS Energy’s generation assets, as well as the environment, and health and safety functions.

Leigh has built an impressive track record as a collaborative and effective leader managing complex and geographically diverse operations in the energy industry both in Australia and overseas. 

He has a nuanced understanding of the challenges facing the energy industry and has a real passion for empowering people to build a constructive culture.

Prior to joining CS Energy, Leigh fulfilled a variety of roles at Western Australian energy company Synergy across their coal, gas and renewable assets. Before that, he worked for the NZX listed Contact Energy managing their gas-fired assets in Auckland, Hamilton and Napier, as well as the Oakey Power Station in southern Queensland.

Leigh began his career in the energy industry as an I&C Technician at Callide Power Station in 1997.


Andrew Varvari

Andrew Varvari

Executive General Manager Corporate Services 
LLB, B-Bus, G Dip App Fin (Sec Inst), F Fin, Grad ICSA, GAICD

Andrew Varvari leads CS Energy’s key corporate functions including human resources, organisational development, industrial relations, legal, risk, assurance, Board secretariat and corporate affairs. As an experienced energy and resources executive with over 15 years in the industry, and 15 in executive leadership roles, Andrew focuses on safely delivering high value business outcomes.

Andrew joined CS Energy in 2012 and has performed a variety of executive roles, including Executive General Counsel and Company Secretary, Acting Chief Financial Officer, and the role of Executive General Manager People & Safety until 2017, when his responsibilities were expanded to include additional corporate functions to leverage greater alignment and cross functional working relationships, providing strategic counsel, advice and support across CS Energy’s portfolio.

Prior to joining CS Energy, Andrew led BG Group plc’s legal function in Australia, which included responsibility for QGC’s Legal, Secretariat, Business Services and IT functions. Between 2007-2012, Andrew played a key role in the development of Shell’s upstream and midstream businesses as part of its Executive Leadership Team, including the integration of the existing Queensland Gas Company and BG Australia businesses following the 2008 takeover of QGC by BG Group plc, and the development and construction of the $20 billion Queensland Curtis LNG project.

Andrew’s experience also includes five years in legal and executive roles at Stanwell Corporation and seven years in private legal practice.


Colin Duck

Colin Duck

Executive General Manager Asset Management
BE (Hons), MBA

Colin Duck leads our Asset Management division where he has responsibility for asset management strategy, engineering, capital projects, unit overhauls, plant data analysis and operational excellence. Colin joined CS Energy in 2017 following over a decade of guiding energy companies through operational and industry change.

His strategy and leadership experience spans a diverse range of energy production including coal-fired power stations, renewable energy and gas production and storage in both private enterprise and government owned corporations. This is backed by extensive experience in power station engineering and operation. Colin has a particular interest in working with people to successfully embed a culture of performance. He has a track record of transforming business performance while enhancing safety, cost efficiency and productivity.

Prior to joining CS Energy Colin held various roles with AGL. These included transforming AGL’s gas business from an exploration business to a commercially sound operational business and streamlining AGL’s gas and renewable fleet into one efficient business unit. While he was a member of Macquarie Generation’s executive team Colin managed the operation of its two major power stations, implementing a new structure and processes, and negotiating a new enterprise agreement to drive operational excellence. 

He was also instrumental in preparing Macquarie Generation assets and operations for a successful sale.