CAISO's Load-Balancing EDAM Math Questioned by CPUC Staff and Stakeholders
California Public Utilities Commission staff and several stakeholders have raised concerns about the math behind California Independent System Operator's Extended Day-Ahead Market (EDAM) load-balancing adjustments.
The California Independent System Operator's (CAISO) Extended Day-Ahead Market (EDAM) has been under scrutiny following comments filed by the California Public Utilities Commission's (CPUC) Energy Division and several stakeholders.
CAISO's EDAM, the first Western day-ahead market, launched in May. The market has seen some discrepancies in its data, with CPUC staff questioning the math behind CAISO's load adjustments on June 11 and August 4. The staff noted that it is unclear why CAISO made a 592.50 MW load adjustment on June 11 and questioned the math behind CAISO's adjustment of 3,590 MW on August 4.
The CPUC staff also expressed concerns about the methodology behind CAISO's conclusions, stating that it would be helpful if CAISO could explain the reason for the Residual Unit Commitment (RUC) load adjustments on June 11. The staff noted that the additional 3,590 MW is "four times as much of the requirement" and is difficult to understand how moving from the 90% uncertainty to the 97.5% uncertainty would increase the requirement nearly fivefold.
The Six Cities, a group of six cities in California, also filed comments asking for an ongoing cost-benefit analysis for EDAM. They noted that the market has seen "extremely high resource commitments" made by CAISO and market participants, compared to the "negligible benefits" of the market in its first two months.
The Six Cities also questioned CAISO's $11.38 million EDAM benefits estimate, stating that the benefits received from participating in the EDAM should be at least roughly proportional to responsibility for market costs.
Powerex Corp., a marketer of wholesale electricity, submitted comments asking CAISO to report congestion revenue based on the area where market participants paid the congestion cost. The company noted that it is unclear how much of the $37.6 million in congestion revenues associated with constraints in the California ISO BAA were paid by market participants in PacifiCorp West and in PacifiCorp East.
The comments were submitted in response to CAISO's Market Performance and Planning Forum Q3 meeting on July 30. CAISO's Market Performance and Planning Forum Q4 meeting is "tentatively" scheduled for October 29.
### Stakeholder Concerns
Several stakeholders have raised concerns about the methodology behind CAISO's conclusions. The CPUC staff noted that currently available public data do not allow stakeholders to reproduce the calculations behind some of CAISO's key results. The staff also expressed concerns about the published data not showing how the calculation produced adjustments of 592.5 MW and 3,590 MW.
Michael Cade, an energy and regulatory analyst, noted that "a similar concern applies" to the Six Cities' comments questioning CAISO's $11.38 million EDAM benefits estimate. He stated that CAISO reports the total and its allocation among the three participating balancing areas, but not the underlying counterfactual results or a dollar breakdown by benefit component.
### Load-Balancing Adjustments
CAISO's load-balancing adjustments have been questioned by several stakeholders. The CPUC staff noted that it is unclear why CAISO made a 592.50 MW load adjustment on June 11 and questioned the math behind CAISO's adjustment of 3,590 MW on August 4.
The CPUC staff also expressed concerns about the methodology behind CAISO's conclusions, stating that it would be helpful if CAISO could explain the reason for the Residual Unit Commitment (RUC) load adjustments on June 11. The staff noted that the additional 3,590 MW is "four times as much of the requirement" and is difficult to understand how moving from the 90% uncertainty to the 97.5% uncertainty would increase the requirement nearly fivefold.
### Congestion Revenue
Powerex Corp., a marketer of wholesale electricity, submitted comments asking CAISO to report congestion revenue based on the area where market participants paid the congestion cost. The company noted that it is unclear how much of the $37.6 million in congestion revenues associated with constraints in the California ISO BAA were paid by market participants in PacifiCorp West and in PacifiCorp East.
### Market Performance and Planning Forum
CAISO's Market Performance and Planning Forum Q3 meeting was held on July 30. The comments were submitted in response to this meeting. CAISO's Market Performance and Planning Forum Q4 meeting is "tentatively" scheduled for October 29.
