Seattle City Light 2016 ANNUAL REPORT | Supplementary Information 90 SYSTEM CAPABILITY & REQUIREMENTS (Unaudited) CHANGES IN OWNED TOTAL GENERATING INSTALLED CAPABILITY (in Kilowatts) TOTAL GENERATION AND LONG-TERM PURCHASED POWER CONTRACTS VS. SYSTEM LOAD SYSTEM REQUIREMENTS (in Kilowatts) Year 1904-09 1912 1914-21 1921 1921 1924-29 1929 1932 1932 1936-37 1951 1951 1952-56 1958 1961 1967 1967 1972 1980 1986 1987 1989-92 1990 1993 1995 2000 2013-2014 2015 Year 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Peak Load A 312,000 733,000 889,000 1,138,000 1,383,000 1,429,387 1,771,550 1,806,341 2,059,566 1,748,657 1,769,440 1,719,020 1,825,819 1,777,096 1,904,735 1,859,875 1,846,708 1,748,833 1,804,708 1,840,792 1,866,792 1,689,000 1,785,000 Average Load 154,030 381,517 512,787 635,275 806,813 848,805 963,686 1,025,898 1,088,077 1,072,692 1,142,383 1,113,513 1,149,380 1,171,596 1,181,325 1,162,375 1,131,365 1,164,725 1,147,771 1,147,112 1,131,464 1,105,847 1,103,892 Plant Cedar Falls Hydro Units 1, 2, 3 & 4 Lake Union Hydro Unit 10 Lake Union Steam Units 11, 12 & 13 Newhalem Hydro Unit 20 Cedar Falls Hydro Unit 5 Gorge Hydro Units 21, 22 & 23 Cedar Falls Hydro Unit 6 Cedar Falls Hydro Units 1, 2, 3 & 4 Lake Union Hydro Unit 10 Diablo Hydro Units 31, 32, 35 & 36 Georgetown Steam Units 1, 2 & 3 Gorge Hydro Unit 24 Ross Hydro Units 41, 42, 43 & 44 Diablo Plant Modernization Gorge Hydro, High Dam Georgetown Plant, performance test gain Boundary Hydro Units 51, 52, 53 & 54 Centralia Units 1 & 2 Georgetown Steam Units 1, 2, & 3 Boundary Hydro Units 55 & 56 Lake Union Steam Units 11, 12 & 13 Gorge Units 21, 22, & 23, new runners Gorge Unit 24 Centralia Transmission Upgrade South Fork Tolt Unit 81 Centralia Units 1 & 2 Boundary Hydro Units 53 & 55 rewind Boundary Hydro Unit 56 upgrade Kilowatts Added 10,400 1,500 40,000 2,000 15,000 60,000 15,000 (10,400) (1,500) 155,400 21,000 64,900 450,000 35,000 46,000 2,000 639,400 102,400 (23,000) 400,000 (40,000) 4,600 32,000 5,000 16,800 (107,400) 39,000 39,000 Capability A Total Kilowatts 10,400 11,900 51,900 53,900 68,900 128,900 143,900 133,500 132,000 287,400 308,400 373,300 823,300 858,300 904,300 906,300 1,545,700 1,648,100 1,625,100 2,025,100 1,985,100 1,989,700 2,021,700 2,026,700 2,043,500 1,936,100 1,975,100 2,014,100 2010 2009 2008 2007 Long-term purchased power contracts 2011 2012 2013 2014 2015 2016 A Capability is the maximum capability of generators and associated prime movers expressed in kilowatts (kW). (megawatt hours) Total generation System load 16,000,000 14,000,000 12,000,000 10,000,000 8,000,000 6,000,000 4,000,000 2,000,000 0 A Peak Load (highest single hourly use).