As of the end of FY2023
| At the end of FY | TEPCO | In Tokyo's 23 wards | Total of 10 EP Co. | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Overhead Lines (km) |
Underground Lines (km) |
Underground Installation Rate (%) |
Overhead Lines (km) |
Underground Lines (km) |
Underground Installation Rates (%) |
Overhead Lines (km) |
Underground Lines (km) |
Underground Installation Rate (%) |
|
| 1965 | 15,379 | 2,830 | 15.5 | 2,301 | 2,195 | 48.8 | 69,042 | 5,090 | 6.9 |
| 1970 | 18,393 | 3,764 | 17.0 | 2,331 | 2,704 | 53.7 | 90,553 | 6,943 | 7.1 |
| 1975 | 20,636 | 4,833 | 19.0 | 785 | 3,296 | 80.8 | 104,410 | 8,032 | 7.1 |
| 1980 | 22,964 | 5,967 | 20.6 | 741 | 3,783 | 83.6 | 115,483 | 10,143 | 8.1 |
| 1985 | 24,841 | 6,548 | 20.9 | 695 | 4,018 | 85.3 | 125,154 | 11,513 | 8.4 |
| 1990 | 26,126 | 7,548 | 22.4 | 644 | 4,335 | 87.1 | 131,192 | 13,639 | 9.4 |
| 1995 | 27,706 | 8,820 | 24.1 | 616 | 4,949 | 88.9 | 138,404 | 16,304 | 10.5 |
| 2000 | 28,847 | 10,933 | 27.5 | 619 | 6,373 | 91.0 | 145,020 | 19,645 | 11.9 |
| 2003 | 28,693 | 11,120 | 27.9 | 606 | 6,477 | 91.4 | 146,135 | 20,143 | 12.1 |
| 2004 | 28,661 | 11,178 | 28.1 | 603 | 6,506 | 91.5 | 145,620 | 20,317 | 12.2 |
| 2005 | 28,643 | 11,237 | 28.2 | 602 | 6,567 | 91.6 | 145,795 | 20,551 | 12.4 |
| 2006 | 28,615 | 11,325 | 28.4 | 585 | 6,651 | 91.9 | 145,948 | 20,729 | 12.4 |
| 2007 | 28,563 | 11,510 | 28.7 | 588 | 6,764 | 92.0 | 146,244 | 21,018 | 12.4 |
| 2008 | 28,541 | 11,652 | 29.0 | 573 | 6,769 | 92.2 | 146,213 | 21,345 | 12.7 |
| 2009 | 28,543 | 11,767 | 29.2 | 578 | 6,814 | 92.2 | 157,445 | 25,655 | 14.0 |
| 2010 | 28,556 | 11,925 | 29.5 | 572 | 6,901 | 92.3 | 157,341 | 25,942 | 14.2 |
| 2011 | 28,492 | 12,067 | 29.8 | 572 | 6,975 | 92.4 | 158,403 | 26,191 | 14.2 |
| 2012 | 28,345 | 12,210 | 30.1 | 572 | 7,036 | 92.5 | 158,445 | 26,429 | 14.3 |
| 2013 | 28,247 | 12,312 | 30.4 | 567 | 7,081 | 92.6 | 151,158 | 26,392 | 14.9 |
| 2014 | 28,405 | 12,340 | 30.3 | 567 | 7,075 | 92.6 | 151,389 | 26,772 | 15.0 |
| 2015 | 28,382 | 12,403 | 30.4 | 567 | 7,091 | 92.6 | 151,637 | 27,064 | 15.1 |
| 2016 | 28,365 | 12,325 | 30.3 | 567 | 7,030 | 92.5 | 154,706 | 27,205 | 15.0 |
| 2017 | 28,333 | 12,332 | 30.3 | 567 | 7,023 | 92.5 | 151,513 | 27,150 | 15.2 |
| 2018 | 28,314 | 12,349 | 30.4 | 566 | 6,777 | 92.3 | 151,625 | 27,243 | 15.2 |
| 2019 | 28,391 | 12,413 | 30.4 | 565 | 7,051 | 92.6 | 151,862 | 27,385 | 15.3 |
| 2020 | 28,584 | 12,474 | 30.4 | 566 | 7,059 | 92.6 | 152,298 | 27,434 | 15.3 |
| 2021 | 28,453 | 12,513 | 30.5 | 564 | 7,047 | 92.6 | 152,387 | 27,535 | 15.3 |
| 2022 | 28,480 | 12,557 | 30.6 | 563 | 7,041 | 92.6 | 152,573 | 27,593 | 15.3 |
| 2023 | 28,410 | 12,589 | 30.7 | 556 | 7,026 | 92.7 | 152,475 | 27,589 | 15.3 |
(Note)
- Underground installation rate (%) = ｛Total circuit length of underground lines (extended lines) / (Total circuit length of overhead lines (extended lines) + Total circuit length of underground lines (extended lines))｝ x 100 (%)
- Due to the Accounting Rules for Electricity Business amendment (effective from March 29, 2000), distribution facilities with voltage over 20 kV have been included in transmission facilities since FY1999.
- Figures are given for a total of 9 companies (except Okinawa Power Company) before FY1985.
（Corrected on November 4, 2020）
FY 2018 TEPCO Underground Installation Rate（％） 〔Corrected〕30.4 〔Original〕29.8
FY 2018 In Tokyo's 23 wards Underground Installation Rate（％） 〔Corrected〕92.3 〔Original〕92.2
（Corrected）
(Note) 1.Underground installation rate (%) = ｛Total circuit length of underground lines (extended lines) / (Total circuit length of overhead lines (extended lines) + Total circuit length of underground lines (extended lines))｝ x 100 (%)
（Original）
(Note)1.Underground installation rate (%) = (Total circuit length of underground lines (extended lines)/Total circuit length of overhead lines (extended lines) + Total circuit length of underground lines (extended lines)) x 100 (%)
