Long-Term Statistical Assessment of Frequency Regulation Reserves Policies in the Québec Interconnection

Since 2003, Hydro-Québec Distribution has launched three calls for tenders to procure 3500 MW of wind power. This will bring the projected wind capacity in the Québec Interconnection to 4000 MW in 2015, for about 5% energy and 35% maximum hourly penetration rates. This paper presents two statistical approaches for assessing the additional frequency regulation reserves needed to reliably integrate 3000 MW of wind energy from 23 plants, for which minute/minute output time series were developed over an 11-year period and synchronized with historical load patterns. After description of a generalized dispatch-based approach for separating automatic generation control (AGC) and load-following components, a risk-based allocation method inspired from the BPA 2010 rate case is presented in detail, and then compared with the n × σ approach using the same data set. While the risk-based allocation forecasted AGC and load-following increasing by 1.8% and 20.6% of installed wind capacity, the n × σ criterion resulted in much lower incremental reserves requirements with only 0.4% and 6.8% increases of the AGC (n=4) and load-following (n=2), respectively. In a companion paper, the power grid operations-based simulation approach is presented and its results compared with those of this paper.