 PTT has many subsidiaries, including PTTGC, TOP, BCP, and PTTEP, all of which are working towards producing more environmentally friendly energy.In 2014, Bangchak Petroleum completed its Sunny Bangchak project, a 38-megawatt silicon photovoltaic power plant, the largest of its kind in Southeast Asia.In September 2014, Thai Oil Public Company Limited (TOP), another PTT subsidiary, was recognized as a leader in business sustainability by the Dow Jones Sustainability Index.