Update | March 28, 2023

The AESO launched a new and innovative engagement initiative with industry—a Request for Information (RFI)— to explore potential solutions to mitigate the instantaneous impacts of a sudden supply loss. Industry's response to this approach to resolving challenges was positive, generating a total of 22 submissions. In performing its assessment of all the proposed solutions received to mitigate the identified reliability risks, the AESO considered the following:

• Does the solution address one or more of the three (3) RFI objectives?
  1. Address the risks of significant power swings and/or frequency excursions caused by the sudden loss of the Alberta–British Columbia intertie (B.C. intertie).
  2. Address the adverse impacts of inadvertent in-rushes on the B.C. intertie and Montana–Alberta Tie Line (MATL), so that a generation supply loss within Alberta is less likely to cause the interties’ capabilities to be exceeded.
  3. Improve frequency response under current and potential future MSSC limits and reduce the risk that load shedding will be required to limit frequency excursions caused by loss-of-supply events while islanded.
• Is the solution technically feasible and if so, in which of the following implementation time horizons?
  1. Near-term (2023)
  2. Short-term (1-2 years)
  3. Mid-term (2-5 years)
  4. Long-term (5-10+ years)
• Does the solution fit within the existing regulatory framework?
• Does the solution provide economic benefits to Albertans?

Submissions received through the RFI fit within a broad range of technological categories including:

1. A back-to-back high-voltage direct-current (HVDC) converter on MATL.
2. Battery Energy Storage Systems (BESS) using inverter-based resource (IBR) technology in differing configurations (stand-alone, hybrid, etc.).
3. Generators with fast-ramping capabilities.
4. Higher availability load shedding options.
5. Synchronous inertia sources delivering reduced rate of change of frequency (RoCoF).
6. Other.

Through the assessment, each submission was prioritized based on feasibility to address the RFI objectives and the expected implementation time horizons:

• Priority #1: Assess further as a near-term solution.
• Priority #2: Assess further as information to inform future product, market design or wires solutions in the short- and medium-term.
• Priority #3: Hold and review further at an appropriate time for longer-term consideration regarding future product, market- design or wires solutions.

Next Steps

The Alberta Interconnected Electric System (AIES) is undergoing a period of rapid transformation and the AESO 2023 Reliability Requirements Roadmap (Reliability Roadmap) identifies system operating challenges that are beginning to emerge. The Reliability Roadmap documents the AESO’s plans to further investigate and address those challenges and identifies the AESO’s current highest priority to be ensuring sufficient frequency response capability. In alignment with the RFI objectives and in response to immediate frequency-related operational challenges as per the Reliability Roadmap assessment, the following steps are being undertaken now to enable implementation in the near-, short- and medium-term.

The submissions in this RFI may also be considered as part of a holistic review of the evolution of the energy market to support Alberta through the transformation to a decarbonized future. The AESO will begin engaging with stakeholders on this review in the latter half of 2023.

Near-Term Implementation

The AESO engaged stakeholders who submitted solutions for BESS that are immediately capable of providing fast frequency response (FFR) service when the grid is operated as a frequency island. This FFR service will enable generator output at the current islanded MSSC limit of 425 MW, and potential future MSSC limits, to support supply adequacy when the grid is operated as a frequency island. The AESO has commenced bilateral negotiations to procure this service to immediately address reliability challenges through to December 31, 2024.

The AESO has also engaged existing Import Load Shed Agreement (ILSA) service providers to provide frequency services during islanded operations, effective March 31, 2023, through to December 31, 2024. To support the immediate frequency challenges which arise when the grid is operating as a frequency island, 325 MWs of this FFR volume is expected to be contracted.

The AESO is also exploring the potential to increase the contracted volume of FFR through Load Shed Service for imports (LSSi) in the near-term.

Short-Term Implementation

A technology-agnostic solution to ensure sufficient frequency response capability while interconnected to the Western Interconnection and while operating as a frequency island is being designed for implementation prior to, or by, the beginning of 2025 at the latest. Potential solutions will leverage information received through the RFI, and lessons learned through the FFR Pilot.

Medium-Term Implementation

The Reliability Roadmap discusses the impact on frequency stability following a sudden supply loss of the combined MATL and B.C. intertie when both are in-service and operating as alternating current (AC) interties. As discussed in the 2022 Long-term Transmission Plan, the AESO has been assessing plans to restore intertie scheduling capability, including B.C. intertie restoration options, and the potential for a back-to-back high-voltage direct-current (HVDC) converter on MATL. The AESO will continue to assess how a MATL HVDC converter could contribute to improving Alberta’s frequency response capabilities and will leverage information received through the RFI to determine the implementation approach should there be a decision to proceed.

As the AESO continues to progress with the implementation of the short- and medium-term initiatives, the AESO will engage further with stakeholders and additional information will be provided on this AESO Engage RFI project page.