In the same year American depositary share of HPI was listed on the New York Stock Exchange.

[8] In 2000, HPI also absorbed fellow sister listed company Shandong Huaneng Power Development.

In April 2008, HPI also acquired a special-purpose vehicle SinoSing Power from China Huaneng Group for approx.

[12][13] That SPV acquired Tuas Power from Singapore government owned Temasek Holdings for SG$4.235 billion (approx.

As of 31 December 2017[update], ultimate parent company China Huaneng Group (CHNG) owned 10.23% shares of Huaneng Power International directly, plus additional 33.33% via a wholly owned subsidiary Huaneng International Power Development Corporation, another 3.11% shares via another subsidiary, Hong Kong incorporated, China Hua Neng Group Hong Kong (Chinese: 中國華能集團香港) and lastly 0.49% shares via mainland incorporated subsidiary, China Huaneng Finance (Chinese: 中国华能财务),[19] for a total of 47.16% shares of HPI.