Document wKD4yD2Mdz9de8pq7Jor4gZgd

USCA Case #24-1190 Document #2062093 Filed: 06/27/2024 Page 18 of 123 Thermal/Natural Gas Generation - Online Thermal/Coal Generation - Online Wind Generation - Online Total Solar Generation - Online Total Short Term Contracts - Max 39. NorthWestern's proportion of generation resources that arc renewable compares highly favorable to other utilities. In 2021, 56% of NorthWestern's electric generation was from carbon-free resources, which compares to about 42% generated by the U.S. electric power industry as a whole. 40. Despite the significant improvement in NorthWestern's generation capacity, including acquisitions of hydroelectric plants and wind farms, North Western's resource portfolio of owned resources and long-term contracts is not yet sufficient or "reliable," as defined by regional planning organizations, including the Western Regional Adequacy Program ("WRAP"), of which NorthWestern is a founding member. 41. In periods of peak loads, North Western often does not have sufficient capacity, meaning that NorthWestern must make market purchases of capacity and energy to meet customers' needs. 42. Periods of peak load arc those times when customers' demand for electricity is particularly high. This tends to occur during periods of extreme weather, during the coldest winter days (below 10 degrees Fahrenheit) when more electricity is used for heating purposes and during the hottest summer days (above 90 degrees Fahrenheit) when more electricity is used 17 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000310-00018 SC_EVERSPLIT0006273