Reliability Standard: IRO-001-1.1
Issue: TWP as a GO, self-reported that it failed to comply with reliability directives issued by its RC (per R8). TWP was under a production curtailment per the direction of its RC due to inclement weather experienced at one of TWP's locations that resulted in constrained transmission facilities. The RC provided several levels of production curtailment, limiting TWP from 105 MW to 120 MW of generation for different periods during the Constrained Period. TWP reported ten instances where production unintentionally and momentarily exceeded the curtailment level.
Finding: MRO found the issue posed a minimal risk to the reliability of the BPS since TWP is interconnected to a 230 kV transmission line, and the nature of the excursions (the average was 7.6 MW for 6.5 minutes) would not pose anything more than a minimal risk to the 230 kV transmission line and to the BPS. In addition, TWP has a non-dispatchable intermittent wind generation resource straddling the border of North Dakota and South Dakota, consisting of 120 1.5 MW WTGs, with an aggregate capability of 180 MW.