Agence France-Presse: A German firm said Wednesday it has signed a deal to extend a South Korean solar energy plant which is already Asia’s largest. Conergy said in a statement it has reached a framework agreement on a 20-million-euro (29.8-million-dollar) project to expand the plant at Sinan in the southwest of the country. The extension is expected to be completed by year-end and will add 4.35 megawatts to the existing 19.6 MW capacity of the plant, which became fully operational in June at a cost …