Rwanda has signed a $400 million deal to produce bottled methane gas from Lake Kivu, which lies in the volcanic region of Rwanda's border with the Democratic Republic of Congo and is known for emitting dense clouds of methane. The project will suck gas from the lake's deep floor and bottle it for use as fuel, which, in turn, should help prevent toxic gas from bubbling to the surface. The bottled methane is intended to help cut local reliance on wood and charcoal, the fuels most households and tea factories use in the East African nation.