MISO is now aiming for a six-day horizon for its new, comprehensive multiday operating margin forecast.

“Our plan is to roll this out incrementally,” said Chuck Hansen, of MISO’s market design team.

The first iteration of the forecast will look ahead six days, be updated once daily and estimate a daily peak hour on the systemwide, MISO Midwest and MISO South levels. Future versions of the forecast may contain multiday hourly load and wind forecasts, behind-the-meter generation forecasts, interchange forecasts and data on emergency resources.

Hansen said the idea is to build a “data warehouse” and flexible analytical platform so that MISO can easily add new sources of information for a more nuanced forecast.

“We want to be able to change the report without starting from scratch,” Hansen said.

MISO introduced the concept last month, although it offered few specifics on what the forecasting would entail. (See MISO Adding Week-ahead Forecasts.) The new forecast will be purely informational for market participants and won’t be tied to financial commitments.

Since last month, MISO has analyzed more than five years’ worth of its systemwide load and wind generation forecasting and found it has been “generally accurate,” Hansen said.

He said he would return to the Market Subcommittee in August with more details and a more precise timeline on the project.

Short-term Reserve Filing Coming Shortly

MISO will file with FERC in mid-August a proposal to create a short-term reserve product, staff told the Market Subcommittee.

The RTO said it hopes to roll out the product in mid-2021, supported by a soon-to-be-replaced market platform. It also plans a post-implementation review in 2023 to gauge the product’s performance and delivered cost savings.

Based on simulations, MISO expects the reserves to deliver an estimated $5 million in net annual production benefits and a $1.6 million reduction in annual revenue sufficiency guarantee payments.

After stakeholders questioned the analysis behind the $5 million savings, staff said the RTO performed a rough estimate of the benefits based on the best available information.

The product will be designed to furnish capacity within 30 minutes. MISO expects it will help better manage the regional directional transfer limit and help local areas that lack available and flexible resources, especially in southeastern Louisiana in Zone 6 and East Texas in Zone 7, both of which have local reliability issues. (See MISO Prototyping Short-term Reserve Product.)

MISO has set a $100/MW market-wide demand curve for the reserves, so the market is designed to naturally clear energy before it clears the reserve product. The product will be subject to monitoring for physical and economic withholding just like ancillary services, with mitigation measures only applied in constrained regions and zones, not market-wide. Offers below $10/MWh will be excluded from economic withholding monitoring.

— Amanda Durish Cook