Elevated methane and carbon dioxide concentrations in Lake Kivu, once considered potentially lethal to local inhabitants during volcanic events, will now help provide fuel to power Rwanda’s electric grid.

The KivuWatt gas extraction facility is 13 km offshore. Image source: ContourGlobal.Inauguration of the KivuWatt power plant adds 26 MW to the grid in a nation where 25% of the population is connected to an electricity supply. U.S.-based ContourGlobal developed the power station as the first phase in a project intended to add more than 100 MW of generating capacity by tapping the lake’s methane resource.

Extraction of gas for power generation has the added benefit of reducing methane concentrations that could result in the release of toxic gases and possibly an explosion. The process involves a gas extraction facility 13 km offshore to bring gas-rich waters from a pressure of 35 bar to 2 bar. Using a gas separator, gas bubbles are extracted from the water.

The gas mixture is washed to produce clean methane gas, which is then transported to the onshore power plant for use in combustion engines to generate electricity (see video).

In a second phase, as many as three barges will be added to this configuration by 2019 to provide an additional 75 MW of generating capacity.