- 2001: Establishment of the 5.05 enterprise on the basis of the staff of Song Da 5 Company in the Central Region and Central Highlands.
- 2004: Establishment of Song Da 505 Joint Stock Company in accordance with Decision No 980 / QĐ-BXD dated 22/6/2004 of Ministry of Construction, Executing of PleiKrong, Se San 3A hydropower projects. The General Meeting of Shareholders was established on July 25th, 2004 passed the Charter of organization and operation of the Company. On August 09th, 2004, Song Da 505 Jsc. was granted the certificate of business registration for the first time.
- 2006: On December 22nd 2006, Song Da 505 Jsc. was participating in the stock exchange. Listed on the stock market at Hanoi Securities Trading Center with stock code S55.
- 2007: Annual General Meeting of Shareholders on March 28th, 2007 passed the resolution to increase charter capital from 7 billion VND to 24.96 billion VND.
- 2008: Established Branch 555 on October 20th, 2008.
- 2009: Establishment of the Laboratory branch on January 6th, 2009, Branch 515 on April 3rd, 2009 and Branch 525 on December 2nd, 2009.
- 2013: Officially withdrew state capital, became a joint stock company with 100% private capital.
- 2015: The Company increased its charter capital from 24.96 billion VND 49.92 billion VND from the Company’s surplus capital; contributed capital in DATC Global Trading and Investment Company to invest in Bac Ninh hydropower project in Lao Cai province – subsidiary of the Company since May 5th 2015; Invest in Song Ong Hydropower Jsc. to become an affiliate of the Company from June 30th 2015; passed through the dissolution of Branch 555 from July 01st 2015; Dissolution of the Laboratory branch and Branch 525 from January 01st 2016 to restructure the organization, minimize intermediary costs.
- 2016: Bac Na hydropower project in Lao Cai province consists of 2 units with the capacity of 17MW invested by the Company has officially joined the National Grid since December 2016.
- 2017: The Company completed the acquisition of 98% of shares in Viet Hoang Investment and Development Jsc. (now EHULA Jsc.) – to invest in two (02) hydropower projects: Nam Bum 1 and Nam Bum 2 with a total capacity of 36MW. On August 10th 2017, the Company increased its chartered capital from 49.92 billion VND to 59.90 billion VND from the payment of dividends in 2016 by shares to existing shareholders.
- 2018: Completing the increase of charter capital to 100 billion VND. Invested in EHULA shares to implement the investment in the construction of the Nam Bum 1 hydropower project.
- 2019: Dissolution of the Branch 515 from April 01st 2019.
- 2020: completed the commercial power generation of 02 projects: Bac Na 1 and Nam Bum 1 hydropower plants.
- 2022: established a subsidiary – S55 Construction Joint Stock Company; Power generation of the Nam Bum 2 hydropower project.
- 2023: acquired 100% of the capital at ANI SH LLC to perform the management and operation of power plants.
- 2024: Acquire 99.9% of capital at Son Hai Lai Chau Development Investment Joint Stock Company to own the Hydropower Plant Project with a capacity of 9.9MW.