6. Reserve calculations
At BPA, there are three types of reserves. Regulation reserves cover differences between the supply and load within 10 min intervals, following reserves apply from one 10 min period to the next, while balancing reserves cover imbalances between forecast and supply at the 1 h horizon, with a 99.5 percent reliability requirement . Capacity-up reserves are reserves associated with a deficit of AZD1480 relative to forecast. Capacity-down reserves are reserves associated with a surplus. The Federal Energy Regulatory Center (FERC) has also mandated 15 min transmission scheduling to assist in integrating variable sources . Unfortunately, wave data is not available at the 15 min resolution. Consequently, the reserve calculations were run for the 1 h horizon.
Table 4 shows the reserves associated with the load, and each of the renewable energy sources, for the overall period, January 1, 2012 through December 31, 2013. However, reserves are not independent of scale, so the values are also expressed as a percent of power. For capacity down reserves, normally expressed as a negative number, the ratio is calculated using the absolute value.