As of the end of FY2023
| Date | Special Note |
|---|---|
| August 18, 1959 | Thermal power becomes primary power source, with hydroelectric next |
| December 10, 1965 | Operation of Yagisawa Power Station (TEPCO's first pumped storage plant) (80MW) was started |
| March 30, 1968 | Generation capacity surpasses 10GW |
| April 24, 1970 | Operation of Minami Yokohama Thermal Power Station Unit 2 (350MW) (world's fist LNG-only thermal power) was started |
| March 26, 1971 | Operation of Fukushima Daiichi Nuclear Power Station Unit 1 (460MW) was started. |
| June 16, 1973 | Coal-only thermal power was abolished in Japan (Shin-Tokyo Thermal Power Station was the last) |
| July 18, 1974 | Generation capacity surpasses 20GW |
| September 28, 1974 | Operation of Kashima Thermal Power Station Unit 5 (first 1,000MW capacity from single unit in Japan) was started |
| October 12, 1978 | Operation of Fukushima Daiichi Nuclear Power Station Unit 4 was started (nuclear power surpasses hydroelectric power) |
| October 24, 1979 | Operation of Fukushima Daiichi Nuclear Power Station Unit 6 (1,100MW)was started (Total power station output was 4,696 MW) |
| October 26, 1979 | Generation capacity surpasses 30GW |
| September 11, 1981 | Shin-Takasegawa PowerStation was established (maximum output 1,280MW, single-unit output 320MW) |
| April 20, 1982 | Operation of Fukushima Daini Nuclear Power Station Unit 1 (1,100MW) was started |
| December 17, 1982 | Operation of Tanbara Power Station Units 1, 4 (300MW each) was started |
| September 18, 1985 | Operation of Kashiwazaki-Kariwa Nuclear Power Station Unit 1 (1,100MW) was started |
| July 4, 1986 | Operation of Tanbara Power Station Units 2, 3 (300MW x 2) was started |
| November 6, 1986 | Operation of all units at Futtsu Thermal Power Station Group 1 (1,000MW) was started |
| August 25, 1987 | Operation of Fukushima Daini Nuclear Power Station Unit 4 (1,100MW) was started Fukushima Daini Nuclear Power Station was established (Total output was 4,400MW, capacity of nuclear power facilities surpasses 10GW) |
| September 18, 1987 | Operation of Higashi Ohgishima Thermal Power Station Unit 1 (1,000MW) was started Generation capacity surpasses 40GW |
| July 8, 1988 | Operation of Imaichi Power Station Unit 1 (350MW) was started |
| June 23, 1989 | Operation of Hirono Thermal Power Station Unit 3 (1,000MW) was started |
| March 12, 1991 | Operation of Higashi Ohgishima Thermal Power Station Unit 2 (1,000MW) was started |
| December 20, 1991 | Operation of Imaichi Power Station Units 2, 3 (350MW x 2) was started Imaichi Power Station completed (maximum output 1,050MW, single-unit output 350MW) |
| January 22, 1993 | Operation of Hirono Thermal Power Station Unit 4(1,000MW) was started |
| June 24, 1994 | Operation of Shiobara Power Station Units 1, 2 (300MW x 2) was started Generation capacity surpasses 50 GW |
| July 7, 1994 | Operation of Goi Thermal Power Station Unit 6 Gas Turbine (126MW) was started |
| June 16, 1995 | Operation of Shiobara Power Station Unit 3 (300MW) was started |
| July 2, 1997 | Operation of Kashiwazaki-Kariwa Nuclear Power Station Unit 7 (1,356MW) was started Kashiwazaki-Kariwa Nuclear Power Station completed (the world's largest nuclear power station with total output of 8,212MW) |
| January 21, 1998 | Operation of all units of Yokohama Thermal Power Station Group 7 (1,400MW) was started |
| January 22, 1998 | Operation of all units of Yokohama Thermal Power Station Group 8 (1,400MW) was started |
| March 25, 1999 | Operation of Hachijojima Geothermal Power Station (3.3MW) was started (TEPCO's first geothermal power station) |
| December 3, 1999 | Operation of Kazunogawa Power Station Unit 1 (400MW) was started |
| March 31, 2000 | Operation of Hachijojima Wind Power Station (0.5MW）was started (first commercial wind power plant for a power company) |
| April 7, 2000 | Operation of all units of Chiba Thermal Power Station Group 1 (1,440MW) was started |
| June 8, 2000 | Operation of Kazunogawa Power Station Unit 2 (400MW) was started |
| June 15, 2000 | Operation of all units of Chiba Thermal Power Station Group 2 (1,440MW) was started |
| March 6, 2001 | Operation of Shinagawa Thermal Power Station Group 1,Unit 2 (380MW) was started Generation capacity surpasses 60GW |
| August 20, 2003 | Operation of all units of Shinagawa Thermal Power Station Group 1 (1,140MW) was started |
| November 13, 2003 | Operation of all units of Futtsu Thermal Power Station Group 3 (1,520MW) was started |
| December 12, 2003 | Operation of Hitachinaka Thermal Power Station Unit 1 (1,000MW) was started |
| July 12, 2004 | Operation of Hirono Thermal Power Station Unit 5 (600MW) was started |
| December 22, 2005 | Operation of Kannagawa Hydroelectric Power Station Unit 1 (470MW) was started |
| February 5, 2009 | Operation of all units of Kawasaki Thermal Power Station Group 1 (1500MW) was started |
| October 5, 2010 | Operation of all units of Futtsu Thermal Power Station Group 4 (1,520MW) was started |
| April - September 2011 | Operation of emergency power sources was started at following power stations: Chiba Thermal Power Station (668MW) Anegasaki Thermal Power Station (5.6MW), Sodegaura Thermal Power Station (112.2MW),Yokosuka Thermal Power Station (329.6MW), Kawasaki Thermal Power Station (128MW),Ohi Thermal Power Station (209MW), Hitachinaka Thermal Power Station (253.23MW) |
| August 10, 2011 | Operation of Ukishima Photovoltaic Power Station (7MW) was started (TEPCO's first Photovoltaic Power Station) |
| December 19, 2011 | Operation of Ohgishima Photovoltaic Power Station (13MW) was started |
| January 27, 2012 | Operation of Komekurayama Photovoltaic Power Station (10MW) was started |
| March 31, 2012 | The emergency power sources of Hitachinaka Thermal Power Station (253.23MW) were abolished |
| April 19, 2012 | Fukushima Daiichi Nuclear Power Station Units 1-4 (2812MW) were abolished |
| June 7, 2012 | Operation of Kannagawa Power Station Unit 2 （470MW) was started |
| June - July 2012 | Operation of emergency power sources was started at Chiba Thermal Power Station (334MW) and Kashima Thermal Power Station (804MW) |
| February 1, 2013 | Operation of Kawasaki Thermal Power Station Group 2, Unit 1 (500MW) was started |
| March 31, 2013 | The emergency power sources of Yokosuka Thermal Power Station (75.9MW) and Sodegaura Thermal Power Station (112.2MW) was abolished |
| May 10, 2013 | The emergency power source of Yokosuka Thermal Power Station (253.7MW) was abolished |
| December 3, 2013 | Operation of Hirono Thermal Power Station Unit 6 (600MW) was started |
| December 18, 2013 | Operation of Hitachinaka Thermal Power Station Unit 2 (1000MW) was started |
| January 31, 2014 | Fukushima Daiichi Nuclear Power Station Unit 5, 6 (1884MW) were abolished |
| March 14, 2014 | Hachijojima Wind Power Station (0.5MW) was abolished |
| April 1, 2014 |
Abolition of urgently-installed power generators at Kawasaki Thermal Power Station (128MW) and Oi Thermal Power Station (128MW) |
| June 9, 2014 |
Operational start of Unit 4 of Kazunogawa Hydroelectric Power Station (400MW) |
| June 18, 2014 |
Operational start of Group 7 of Kashima Thermal Power Station (1260MW) (Conversion of urgently-installed power generators into combined cycle type) |
| July 31, 2014 |
Operational start of Group 3 of Chiba Thermal Power Station (1500MW) (Conversion of urgently-installed power generators into combined cycle type) |
| March 31, 2015 |
Abolition of urgently-installed power generators at Anegasaki Thermal Power Station (5.6MW) and Oi Thermal Power Station (81MW). |
| August 28, 2015 |
Operation of East Izu Wind Farm (18MW) was started. (TEPCO's first wind farm) |
| January 29, 2016 |
Operation of Kawasaki Thermal Power Station Group 2, Unit 2 (710MW) was started. |
| November 24, 2016 |
Shinanogawa Hydro Power Station increased water intake and power output from 169MW to 181MW. |
| June 29, 2016 |
Operation of all units at Kawasaki Thermal Power Station Group 2 (1920MW) was started. |
| March 31, 2017 |
Yokosuka Thermal Power Station Units 3 to 8 and the Gas Turbine of Unit 1, 2 (Total 2274MW) were abolished. |
| August 10, 2017 |
Futtsu Thermal Power Plant Unit 2 system rated output change (1 GW→ 1.12 GW) |
| March 30, 2018 |
Goi Thermal Power Plant Units 1~6 (total output: 1.886 GW) decommissioned |
| January 1, 2019 |
Commercial operation of offshore wind power station off the coast of Choshi (2.4MW) was started. |
| March 29, 2019 |
Hachijojima Geothermal Power Station (3.3MW) was abolished. |
| April 1, 2019 |
Thermal and fuel facilities of TEPCO Fuel & Power, Inc. were transferred to JERA Co., Inc. |
| September 30, 2019 |
Fukushima Daiichi Nuclear Power Station Unit 5, 6 Units 1-4 (4400MW) was abolished. |
| November 24, 2022 |
Yagisawa Power Station Unit 2 (80MW) was abolished. |
