SK Ecoplant, an affiliate of SK Group – the third largest conglomerate in South Korea, has formed a $200-million joint venture for rooftop solar energy development in Vietnam. The joint venture between SK Ecoplant and Nami Solar, a subsidiary of Nami Energy in Ho Chi Minh City, will develop a 250-MWp rooftop solar power project to serve businesses, including South Korean firms that want green energy and lower energy costs.