Saudi Electricity has said that a consortium led by Japan's Marubeni Corp has proposed the lowest tariff to build a 2,000 megawatt power plant in Riyadh, Reuters has reported. The consortium, which includes Kansai Electric and Saudi Masader Co for Power, Water and Gas, had proposed a levelised electricity cost - which includes costs of production, fuel, financing and operations - of 0.077 riyals per kilowatt hour, the company said.