Shoulder season step up: WECC power markets short-term outlook September 2019

The first half of September saw very low wind generation as the first week’s total wind output was around just about a 23% capacity factor on average. However, the second half of the month highlighted just how volatile weekly wind availability has become, as capacity factors averaged 41% the last week of the month. The volatility in wind output has significant impact on thermal generation balances, with gas needing to fill in the gap when the wind generation turns down.