Mr. Adam Borgatti reports

AECON PARTNERSHIP EXECUTES AGREEMENT FOR THE SIMCOE BATTERY ENERGY STORAGE SYSTEM PROJECT IN ONTARIO

Simcoe Battery Project General Partnership Inc., in which Aecon Group Inc.'s Aecon Concessions is an equity partner, has executed an energy storage facility agreement with Ontario's Independent Electricity System Operator (IESO) to build, own and operate the 150-megawatt/1,200-megawatt-hour Simcoe battery energy storage system project in Norfolk county, Ontario.

Aecon Concessions, Six Nations of the Grand River Development Corporation (SNGRDC), the Mississaugas of the Credit Business Corporation (MCBC), Sitka Power Inc. and NRStor will be ownership partners, and will provide electricity storage services to the IESO through a 20-year agreement, receiving capacity payments from the IESO for capacity services, as well as additional revenue from energy sold into the Ontario electricity grid and ancillary services. Aecon will also serve as the exclusive engineering, procurement and construction (EPC) provider for the balance of plant works, and an EPC agreement with Aecon is expected to be finalized. The target to commence commercial operations is 2030.

"The Simcoe battery project will strengthen grid reliability and support the integration of renewable generation -- helping to provide the resilient energy foundation and critical storage capacity required to support economic growth and meet Ontario's growing electricity demand," said Steve Nackan, executive vice-president and president, Aecon Concessions. "As a diversified development, construction and investment partner, Aecon is strategically focused on opportunities across North America linked to power infrastructure, energy storage, grid expansion and resilience. Our involvement across the full life cycle of this project is a strong example of our One Aecon approach -- harnessing the expertise of our diverse operating sectors, and converting core development and construction capabilities into long-term concession opportunities."

The Simcoe battery project complements Aecon Concessions' ownership interest in the Oneida energy storage project in Ontario, which has been successfully operating since May, 2025, and was developed and delivered by Aecon, SNGRDC, MCBC, NRStor and Northland Power, alongside construction partner Aecon-Six Nations (A6N) general partnership -- a purpose-built team with indigenous partnership at the forefront.

With multidisciplinary North American power infrastructure expertise, Aecon is a leader in Canada's power generation and battery storage sector. Through its completed and continuing work, including the Simcoe battery project, Aecon projects represent approximately one gigawatt of Ontario's delivered or planned projects. In addition to the Oneida energy storage project, Aecon's portfolio of related work in Ontario includes the completed York battery energy storage system (BESS) and Goreway BESS facilities, as well as the continuing South March BESS and Trail Road BESS projects.

About Aecon Group Inc.

Aecon is a North American construction and infrastructure development company with global experience. Aecon delivers integrated solutions to private and public-sector clients through its construction segment in the civil, urban transportation, nuclear, utility and industrial sectors, and provides project development, financing, investment, management, and operations and maintenance services through its concessions segment.

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