The Seoul city government said Monday it produced 185 billion won (US$165 million) worth of energy last year using household waste as fuel, a value equivalent to the price of 1.33 million barrels of crude oil. South Korea is the world\'s fifth-largest crude buyer and depends entirely on imports for its oil needs, according to South Korea\'s (Yonhap) News Agency. Of the 1.1 million tons of combustible household waste produced in Seoul last year, the city government said it reused 730,000 tons as fuel for energy, producing an amount equivalent to the annual heating needs of 190,000 households in the city. The number of households accounts for 14% of all apartments in Seoul in 2010, it added. \"In order to save energy and the environment through heat produced from waste, we need citizens to actively cooperate in separating recyclable waste,\" said a city official. South Korea aims to become one of the world\'s top five green economies by generating more than 10% of its energy from renewable sources by 2030. It currently relies on such sources for less than 2.5% of its energy needs.