JWPA announces the installed capacity of wind power generation in Japan as of the end of December 2020.
They are surveyed by the JWPA.

The cumulative installed capacity at the end of December, 2020
= 4,439 MW, 2,554 units
Net new installation for 2020 (January-December)
= 516 MW, 166 units, 20 sites

The annual new installation has increased about 1.9 times from 270 MW in 2019.
It is the maximum annual installation in wind power history in Japan.

As for offshore wind, Japanese government has announced new aggressive target,
10GW by 2030 and 30GW-45GW by 2045, on 15 Dec 2020
at "Vision for Offshore Wind Power Industry（1st）".
The 2nd meeting of the Council for Government-Industry Dialogue for offshore wind
http://jwpa.jp/page_301_englishsite/jwpa/detail_e.html

The cumulative installed offshore capacity at the end of December, 2020;
58.6 MW, 28 units, 7 sites ,including semi-offshore
14.4 MW, 5 units, 4 sites, excluding semi-offshore
12 MW, 4 units, 3 sites, floating offshore
Net new installation for 2020 (January-December)
-7 MW, -1 units, 0 sites
One 7MW floating turbine at Fukushima was decommissioned in 2020.
No new offshore wind turbines start operation in Japan 2020.

For Port Associated Area, construction works at Akita(55MW) and Noshiro(88MW) have started.
They will start operation in 2022.
国内初の商用洋上風力発電事業　「秋田港・能代港洋上風力発電施設建設工事」本格着工
　On 26 March 2020, by Kajima, in Japanese
　https://www.kajima.co.jp/news/press/202003/26c1-j.htm

For General Common Sea Area, auction has started for;
- Goto, Nagasaki pref. (floating) : around 20MW
- Noshiro-Mitabe-Oga, Akita pref. (fixed bottom) : around 350MW
- Yurihonjo-North, Akita pref. (fixed bottom) : around 350MW
- Yurihonjo-South, Akita pref. (fixed bottom) : around 350MW
- Choshi, Chiba pref. (fixed bottom) : around 350MW
The winners will be announced in 2021.

And, more 10 areas are in the nomination process for auction.
55 projects of 14.4GW in total are in the Environmental Impact Assessment (EIA) process in Jan.2021.