Skip Ribbon Commands
Skip to main content
Sign In


  • Outcome
    On Mar 29, 2012 the ISO revised its default operations and maintenance cost adders, which represent the per-megawatt hour variable, non-fuel costs of running a generating unit at or above its minimum operating level. The ISO increased the number of adder values from two to ten to differentiate costs by technology for all generation resources participating in the market. The ISO will re-evaluate these values every three years. — Effective date: Trading day Apr 01, 2012; FERC Order: Mar 15, 2012 (ER12-806); Tariff amendment filing: Jan 13, 2012; Board of Governors approval: Dec 15, 2011