Long-duration energy storage (LDES) developer-operator Hydrostor intends to enter its compressed air storage project into Ontario, Canada’s recently announced LDES procurement.
Announced 8 May, the Ontario Independent Electricity System Operator (IESO) has launched its Long Lead-Time request for proposal (LLT RFP), aiming to procure up to 800MW of LDES, including pumped hydro.
The LLT RFP is also open to 1TWh of generation resources, and successful projects will be awarded a 40-year contract.
IESO’s LLT RFP builds on its previously announced Long-Term 1 (LT1) and Long-Term 2 (LT2) RFPs.
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The LT1 RFP, at the time, resulted in the largest procurement of battery energy storage system (BESS) capacity in the country’s history, awarding over 850MW of BESS capacity contracts across two tranches during May and June of 2023.
LT2 was launched in July 2025, targeting 3TWh of energy generation, alongside 600MW of new capacity resources.
According to the IESO, “the first Window of the Energy Stream of the LT2 RFP has now concluded. The IESO has executed contracts with 13 Selected Proponents, totaling 1,115.10MW of Maximum Contract Capacity and an aggregate Expected Annual Imputed Production of 2.37 TWh. The capacity stream of the LT2 RFP is still currently active, and Proposals are being evaluated.”
Hydrostor’s A-CAES project
On 13 May, Hydrostor announced the development of the Quinte Energy Storage Centre, an advanced compressed air energy storage (A-CAES) project in Greater Napanee, Ontario.
A-CAES technology functions by compressing air into a storage medium during the charging cycle. When electricity is needed, the compressed air is released and heated, causing it to expand and drive a turbine generator.
The company intends to enter the project into the LTT RFP. As reported by Energy-Storage.news Premium in July 2024, Hydrostor previously intended to submit the project to the LT2 RFP.
While the company did not specify project size in its latest announcement, as covered in that ESN Premium article, it was presented with a planned output and capacity of 500MW/8,000MWh to Greater Napanee’s town council, adjacent to Ontario Power Generation’s Lennox Generating Station.
Hydrostor noted that the 13 May announcement followed the project’s receipt of a Municipal Support Resolution from Greater Napanee, the result of a more than 12-month consultation process that allowed the company to engage with the town’s administration, council, and community members to raise awareness and understanding of the project and its benefits.
Now, the Quinte Energy Storage Centre begins the permitting process, during which, Hydrostor said it will continue to work with the Greater Napanee community and provincial and federal agencies, to obtain municipal, provincial, and federal approvals and permits.
The project is also being developed in partnership with the Mohawks of the Bay of Quinte, who will be an Indigenous equity partner in Quinte.
Hydrostor also claimed that Quinte will generate substantial economic value for local and provincial economies. The company estimates thousands of jobs will be supported during construction, with approximately 40 permanent positions maintained throughout the facility’s anticipated 50-year operational period. The total economic impact is expected to exceed CA$1.4 billion (US$1.02 billion) in contributions to Canada’s GDP.
The project will be funded in part by a previously announced investment from the Canada Growth Fund, who have made available a US$50 million convertible development expenditure loan facility to fund a portion of development costs for Hydrostor’s Canadian projects.
In January 2026 Hydrostor announced a strategic technology and equity agreement to incorporate energy infrastructure equipment manufacturer Baker Hughes’ technology into its main design for its A-CAES solution. This included orders for up to 1.4GW of Baker Hughes equipment for Hydrostor’s flagship projects, including compression, expander, motor, and generator technology.
