Solar panels sit atop the roof of a building at the Lamma island power plant yesterday in Hong Kong. Hongkong Electric Holdings Ltd, the utility controlled by billionaire Li Ka-shing, started the city's biggest solar power project yesterday as part of efforts to help cut pollution. The HK$23 million (US$3 million) solar project will produce enough electricity for 150 families for a year and cut 520 tons of carbon dioxide emissions annually.