EXECUTIVE SUMMARY

Aecon Group Inc., a Canadian infrastructure development and construction company headquartered in Toronto, Ontario, announced that Simcoe Battery Project General Partnership Inc., in which Aecon Concessions is an equity partner, has executed an Energy Storage Facility Agreement with Ontario’s Independent Electricity System Operator (IESO) for the Simcoe Battery Energy Storage System Project. The project will be developed in Norfolk County, Ontario, with a planned capacity of 150 MW / 1,200 MWh.

The Simcoe Battery Project will be owned by Aecon Concessions, Six Nations of the Grand River Development Corporation (SNGRDC), the Mississaugas of the Credit Business Corporation (MCBC), Sitka Power Inc. and NRStor. Under a 20-year agreement with the IESO, the partnership will provide electricity storage services to Ontario’s power system. The owners will receive capacity payments for contracted services while also generating revenue through electricity sales into the Ontario grid and the provision of ancillary services.

Aecon is also expected to serve as the exclusive Engineering, Procurement and Construction (EPC) contractor for the project's balance of plant works. An EPC agreement is anticipated to be finalized following the execution of the Energy Storage Facility Agreement. The project is targeting commercial operations in 2030.

According to Aecon, the battery storage facility is intended to strengthen grid reliability, support the integration of renewable electricity generation and provide additional storage capacity as electricity demand increases across Ontario. The company stated that the project aligns with its strategy of expanding participation in North American power infrastructure, grid modernization and battery energy storage developments.

The Simcoe Battery Project builds on Aecon Concessions' existing ownership interest in the Oneida Energy Storage Project, which has been operating since May 2025. Oneida was developed through a partnership involving Aecon, SNGRDC, MCBC, NRStor and Northland Power, with construction delivered by the Aecon-Six Nations general partnership.

Aecon said its completed and ongoing battery energy storage projects in Ontario now represent approximately 1 GW of delivered or planned capacity. Alongside Oneida, the company's portfolio includes the completed York Battery Energy Storage System and Goreway BESS, as well as the South March BESS and Trail Road BESS, which are currently under development. The Simcoe Battery Project further expands Aecon's presence in Ontario's growing battery energy storage sector while supporting long-term electricity system flexibility and reliability.