Long Term Adequacy Metrics - November 2008

November 1, 2008

The following changes have occurred to the Long Term Adequacy Metrics since the last posting (Long Term Adequacy Metrics - August 2008):

New Generation Projects and Retirements Metric: 

  • Projects completed and removed from list:  
    • Long Lake (180 MW)
  • Generation projects moved to “Active Construction”:  
    • Blue Trail Wind Farm (66 MW)
  • Generation projects moved to “Regulatory Approval”:     
    • Medicine Hat CT 15 (41.5 MW)
    • Scotford Industrial System (18 MW)
  • Generation projects that have been added to “Announced, Applied for AESO Interconnection, and/or Applied for Regulatory Approval":
    • Project 856 (175 MW)
    • Plasco Waste Conversion Facility (15 MW)
    • Keephills 1 Uprate (35 MW)
    • Project 868 (85 MW)
    • Keephills 2 Uprate (35 MW)
    • Project 852 (344 MW)
  • Generation projects that have been added to “Deferred”:
    • Long Lake South (82 MW)
    • Bruderheim Generating Facility (120 MW)
    • Dodds-Roundhill Energy Facility (380 MW)

Changes to generation projects:   

  • Northern Prairie Power Project MCR has changed to 85 MW from 99 MW
  • ECB Envir. North America ISD has changed to 2010 from 2008
  • Fort Hills Mine MCR has changed to 130 MW from 170 MW and ISD has changed to 2011
  • Project 745 ISD has changed to Aug-2010 from Jul-2009
  • Carmon Creek ISD has changed to 2012 from 2010
  • Dunvegan ISD has changed to Jun-2012 from 2011
  • Bow City ISD has changed to 2014

Reserve Margin Metric:

  • The forecasted reserve margin has been updated and has decreased slightly in all years.

Supply Cushion Metric:

  • The forecasted supply cushion has been updated.

Two Year Probability of Supply Adequacy Shortfall Metric:

  • New values for the metric have been calculated with total energy not served increasing from 261 MWh to 951 MWh. This new value is below the 1600 MWh threshold.

1.  New Generation Projects and Retirements Metrics:

The New Generation Projects and Retirements Metric is a summary of generation at various stages of development in Alberta and is shown in Tables 1 to 5 below. In Alberta’s deregulated electricity market competitive forces determine the location, magnitude and timing of new generation additions. Information on prospective generation additions and retirements provides context for the future market in Alberta.  The information is drawn from a variety of public sources and includes new generation, changes to existing generation and retirement of generating units. While the metric includes only new wind generation projects under construction, a list of all new wind projects is available in the AESO Generation Interconnection Queue.

 

Table 1: Generation Projects under Active Construction

 

Table 2: Generation Projects with Regulatory Approval

 

Table 3: Generation Projects that have been Announced, Applied for AESO Interconnection, and/or Applied for Regulatory Approval

 

Table 4: Generation Projects that have been Deferred

 

Table 5: Generation Projects that have Announced to Retire

 

2.  Reserve Margin Metric:

The Reserve Margin Metric, shown in Figure 1, presents a comparison of generation supply and demand in Alberta.  It is calculated by taking the amount of firm generation capacity at the time of system peak that is in excess of the system annual peak demand, expressed as a percentage of the system peak.  Firm generation is defined as installed and active construction generation capacity, adjusting for seasonal hydro capacity and behind the fence demand and generation and excludes wind capacity.  The forecasted reserve margin shows a decline from historically high margins.  The Reserve Margin Metric does not include the numerous projects that are approved or announced.  The reserve margin is graphed with and without intertie capacity since full import capability may not always be available at the time of system peak demand.

 

3. Supply Cushion Metric:

The Supply Cushion Metric provides visibility of the Alberta Interconnected Electric System’s ability to meet peak demand on a daily basis.  The supply cushion is the difference between the daily available firm supply minus daily peak demand.  The supply cushion refines the reserve margin calculation by using daily system peak rather than annual.  Figure 2 presents the estimated daily supply cushion for the next two years.  Figure 3 presents daily peak demand and firm supply by fuel type, as well as interties, wind and back up generation (Rainbow/Rossdale) which are not included in the supply cushion calculation due to the intermittent or uncertain nature of the supply.  When the supply cushion is negative in Figure 2, there is an increased level of reliance on interties, wind and back up generation, as indicated in Figure 3.

4.  Two Year Probability of Supply Adequacy Shortfall Metric:

The Two Year Probability of Supply Adequacy Shortfall Metric is a probabilistic assessment of encountering a supply shortfall over the next two years. It builds on the Supply Cushion Metric by incorporating the probability of wind production, forced generation outages and generation derates into the calculation of hourly firm supply. The calculation estimates, on a probabilistic basis, how much load may go without supply over the next two year period. Based on extensive consultation with stakeholders, when this unserved energy exceeds 1,600 MWh in any two year period (equivalent to one hour 800 MW shortfall in each of the two years), the AESO may take certain actions to bridge the temporary supply adequacy gap without impacting investor confidence in the market. The total energy not served shown in Table 6 does not reach the threshold.

 

Table 6: Two Year Probability of Supply Adequacy Shortfall