CARMEL, Ind. — MISO said it will file by the end of the month to scrap a clunky and all-but-abandoned generator offer style from its tariff. 

The RTO hopes to eliminate the unused weather curve offer function and associated software by March with FERC’s permission. The grid operator said no market participant has ever used the option since its inception in 2009.  

“When I say little-used, I mean never-used,” MISO’s Dave Savageau said during a Jan. 18 Market Subcommittee meeting. “It’s actually less usable, less flexible than normal hourly offers.”  

Until now, MISO combustion turbine and combined cycle generators could have selected a “weather point” — or their megawatt limits according to temperature — during asset registration and submitted weather curves to dynamically set their hourly economic maximum and emergency maximum values in the real-time market based on forecasted temperatures. However, it would have been up to the unit owner to submit a daytime and nighttime temperature estimate apiece daily through MISO’s market user interface. 

The tool wasn’t a “set and forget,” MISO said, because it still was on market participants to submit two temperature points daily for MISO to create hourly maximum limits based on the unit’s weather curve.  

MISO said the two single daytime and nighttime temperature points produced less-accurate forecasts compared to its normal hourly offer parameters. And since the weather curves covered only economic maximum values, market participants still had to submit minimum hourly offers separately.  

Stakeholders attending the subcommittee meeting had no comments or questions on MISO’s plan to discard weather curve functionality.