(EnergyAsia,  May 15, Thursday) — Law firm Herbert Smith said it advised Huaneng Power International, the listed unit of China’s largest power producer, on the HK$26 billion acquisition of SinoSing Power from Huaneng Group including cash and debts. (US$1=HK$7.78).   SinoSing Power is the holding company of Tuas Power in Singapore. Tuas Power is the…