Purpose

We invite all interested stakeholders to provide feedback on the interim draft Cost of Service study report published on Nov. 17, 2025. We are sharing questions in advance to allow stakeholders to prepare and resource adequately, however feedback will be open from Dec. 5, 2025 - Jan. 21, 2026.

Instructions

1. This feedback form is open to all industry stakeholders.
2. Please fill out the sections below as indicated.
3. Only one completed feedback form will be accepted per organization.
4. To upload your your feedback, click on the "Submit Stakeholder Feedback" box below.

All responses are due by January 21, 2026, and will be shared on AESO Engage in their original format. If you have any questions, please email stakeholderrelations@aeso.ca

Stakeholder Questions

Performance review of Rate DTS

12CP charge

Cost-reflectivity at a system-wide level

1. Do you agree with our assessment that in peak seasons the 12CP charge signals to load the drivers of system-wide network investment by encouraging load reduction across periods of high system-wide load? Please provide rationale for your response.

Cost-reflectivity at a planning area level

2. Do you agree with our assessment that the 12CP charge provides little incentive to reduce load in periods of stress on the local transmission network for many areas in the Province? Please provide rationale for your response.

Combing both cost drivers

3. Do you agree with our assessment that in other parts of the year the 12CP charge likely triggers inefficient price response by encouraging a reduction in load in periods when there is spare transmission capacity? Please provide rationale for your response. 

Billing capacity charge

Cost-reflectivity at a system-wide level

4. Do you agree with our assessment that the billing charge likely does not lead to a reduction in system-level network stress due to the low level of synchronicity of load across the entire Province? Please provide rationale for your response.

Cost-reflectivity at a system-wide and area-planning level

5. Do you agree with our assessment that the billing charge likely results in reduced local line stress for some planning areas, i.e., those with high synchronized load? Please provide rationale for your response.

6. Do you agree with our assessment that for areas with asynchronous load, the billing charge likely triggers inefficient price response with limited impact on system-wide or local line stress? Please provide rationale for your response.

Scope and framework for rate review

7. Do you agree with the scope, i.e., the focus on 12CP and the billing capacity? Please provide rationale for your response.

8. Do you agree with the questions investigated in the analytical framework (see Figure 4-17 of the Report)? Would you remove or add other questions? Please provide rationale for your response.

Embedded cost of service (ECOS) study

Identified structural issues with the existing ECOS methodology

9. Do you agree with our assessment that the high-voltage 500 kV assets have complex cost drivers that are attributable to both load and generation, rather than entirely one or the other? Please provide rationale for your response.

10. Do you agree with our assessment that as well as load, generation has also been a driver of historically incurred network costs for network elements operating at voltage levels lower than 500kV? Please provide rationale for your response.

11. Do you agree with our assessment that regional load peaks are an important driver of local transmission investment that is currently not adequately captured by the existing ECOS methodology? Please provide rationale for your response. 

12. Do you agree with our assessment that Point of Supply (POS) costs should not be functionalized as part of the bulk system, given load cannot influence these costs? Please provide rationale for your response. 

13. Do you agree that since the current ECOSS methodology was introduced in 2013, the functional distinction between assets operating at different voltages has become increasingly blurred due to the evolving use of the transmission network? Please provide rationale for your response. 

14. Do you agree with our assessment that the current ‘all-or-nothing’ approach to functionalizing substations as point of connection is likely not durable to future grid developments? Please provide rationale for your response. 

15. Are there any other structural issues with the existing ECOS methodology that we should consider further in our assessment?

 Proposed approach to address the identified shortcomings of the existing ECOS methodology

16. Do you agree with our proposed approach to perform a separate functionalization of the 500 kV assets and classify costs 50/50 between load and generation? Please provide rationale for your response.

17. Do you agree with our proposed approach to recognize generation as a cost driver for System costs by classifying costs in each planning area based on a comparison of peak load and peak generation? Please provide rationale for your response. 

18. Do you agree with our proposed approach to capture system and regional load peaks as cost drivers by allocating a proportion of costs to ‘peak and ‘shoulder’ periods? Please provide rationale for your response.

19. Do you agree with our proposed approach to recognize that a proportion of network costs are incurred to support non-peak use of the system and allocate a proportion of costs to a ‘baseload’ period? Please provide rationale for your response. 

20. Do you agree with our proposed approach to separately functionalize Point of Connection (POC) costs, and to separate POC into POS and Point of Delivery (POD) by assuming POS is fully netted off by deducting customer contributions from POC, and the residual is POD? Please provide rationale for your response.

21. Do you agree with our proposal to merge the former Bulk and Regional functions (other than the 500 kV assets) into a combined ‘System’ function, or are there materially different cost drivers between the asset voltage levels that should be captured? Please provide rationale for your response.

22. Do you agree with our proposal to recognize the dual function of some substations by applying the ‘substation fraction’ methodology? Please provide rationale for your response. 

23. Are there any structural issues with the proposed ECOS methodology that we should consider further in our assessment?

Marginal Cost of Service Study (MCOSS)

24. Do you agree with our proposal to use a regression approach in the MCOSS? Please provide rationale for your response. 

25. Do you agree with the set of variables we have considered in the regression approach? Please provide rationale for your response.

26. Do you agree with the way we determined the acquisition value of transmission assets? Please provide rationale or share an alternative and explain.

27. Do you agree with our assumed asset life for transmission lines and substations? Please provide rationale or share an alternative and explain.

28. Do you agree with the use of Canadian Producer Price Index (PPI) for inflating grid costs? Please provide rationale or share an alternative and explain.

29. Do you agree with our identification of peak load and peak generation as key underlying drivers of network investment? Please provide rationale for your response.

30. Do you agree that the estimates of the long-run marginal cost (LRMC) of the grid with respect to peak load should be generalizable in future grid planning scenarios? Please provide rationale for your response 

31. Do you have any other remarks on the MCOSS?

Conclusions across the three studies

32. How should the studies inform rate design options?

33. Is there any information missing and/or required before we move into rate design?

Purpose

We invite all interested stakeholders to provide feedback on the interim draft Benefit of Service Study published on Nov. 17, 2025. We are sharing questions in advance to allow stakeholders to prepare and resource adequately, however feedback will be open from Dec. 10, 2025 - Jan. 21, 2026.

Stakeholder Questions 

 The AESO is interested in stakeholder feedback on the Benefit of Service Study for the following key themes:

1. Characterization of and analysis for each key industry
2. Qualitative factors and key themes from interviews
3. The techno-economic analysis
4. The determination of drivers of key benefits
5. What this study should (or should not) be used for

Purpose

To define the key problem areas of the current Rate DTS, establish evaluation criteria and generate hypothesis statements that will guide data gathering & analysis in subsequent phases

Instructions

1. To submit your responses, you will need to be registered and signed in on the AESO Engage platform. 
2. You will need to refer to the Draft Hypothesis Statements document  in order to provide feedback.
3. Please click on the "Submit Stakeholder Feedback" box to begin the survey and provide your specific comments. 
   
4. This written feedback is comprised of three "pages", thus allowing you to save your progress after every page of questions, please click "next" to get to the following pages.
5. One completed survey per organization. 
6. All responses will be shared on AESO Engage as received.
7. Responses are due on or before May 29, 2025.

Stakeholder Questions

Draft Hypothesis Statements 

• You will be asked if you agree or disagree with the ten Draft Hypothesis Statements, and provide reasons if you disagree, or if you agree and would like to see changes in wording.
• Please rank the draft hypothesis statements according to which you feel is most to least important (1=most and 10=least).
• Are there any hypothesis statements that should be added?

Scorecard Approach

• Is there alignment between the Draft Hypothesis Statements and proposed Scorecard? Please provide rationale.
• Any further comments on the scorecard approach?

Internal Demand Rates Studies

• Do you have any further comments on the scope of the three studies to be completed in 2025?

Purpose

To define the key problem areas of the current Rate DTS, establish evaluation criteria and generate hypotheses that will guide data gathering & analysis in subsequent phases

Instructions

1. To submit your responses, you will need to be registered and signed in on the AESO Engage platform. 
2. Please click on the "Submit Stakeholder Feedback" box below to begin the survey and provide your specific comments. 
3. Please submit one completed survey per organization. 
4. All responses will be shared on AESO Engage, unless otherwise noted. 
5. Responses are due on or before April 3, 2025.

Stakeholder Questions

Feedback on Current Rate Design

1. In your view, what are the current goals of Rate DTS? 

2. What problem(s)/issue(s) do you want addressed in rate redesign for internal demand rates? 

3. What goals are not being met in the current rate design? 

4. Where is there tension or conflict between goals in the current rate design? 

Scorecard Evaluation Criteria

1. The AESO intends to take a “scorecard” approach to evaluating the performance of the current rates and comparing alternatives. Please select the criteria that should be included in the evaluation. Select all that apply.

• Recovery of total revenue requirement
• Efficient price signals (for transmission-connected customers)
• Ability for distribution utilities to flow through price signals
• Stability and predictability
• Simplicity
• Innovation and cost savings
• Fair, objective, and equitable (minimizing inter-customer subsidies)
• Flexibility and durability

2. For every criteria you did not select, please explain.

3. Are there any other rate design principles or strategic objectives that should be included? Please explain.

4. Any additional comments?

Internal Demand Rates Studies

We have shared the Preliminary Consultant Statements of Work to assist stakeholders with responding to these questions.

1. If the AESO hired one or more consultants to support some or all aspects of any of the following proposed studies, does your organization have a view on which consultants we should (or should not) seek proposals from? (To allow for transparent feedback, these answers will be kept confidential)

Proposed studies: 

• Cost of Service Study
• Benefit of Service Study
• Current Rate DTS performance

2. Any additional comments on proposed studies. (These answers will be shared publicly)