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A New York-based Independent Power Producer (IPP) has appointed Clarke Energy as the preferred bidder for two power plants in Rwanda, which will generate power from dissolved biogas from deep below Lake Kivu.

Symbion Power has secured the rights to deliver two projects in Rwanda on Lake Kivu.

Founder and CEO, Paul Hinks said: “After a long and rigorous competitive process, we have selected Clarke Energy, using GE’s Jenbacher gas engines, as our preferred technology provider. These two power projects at Lake Kivu will increase capacity by 81MW and significantly reduce the current cost of generation in Rwanda.”

The selected bidder will deliver GE’s J620 3MW Jenbacher gas engines across Kivu 56 and KP1 power plants, which are located on the shores of Lake Kivu in Rwanda.

The Kivu 56 project is planned to export 56MW of power into the country’s grid under a 25-year concession. Read more: Methane gas plant to boost Rwanda’s capacity by 2018

KP1 originated as an earlier pilot project, and Symbion has acquired the plant and will upgrade it from 3.6MW to 25MW, which will be delivered to the Rwandan grid system under a separate 25-year concession.

Development of biogas

Lake Kivu, one of the African Great Lakes, is a unique body of water in the world, which at its base is saturated with biogas that is a combination of methane and carbon dioxide gases.

This gas is produced by way of the unique combination of 500-meters (m) depth, heat originating from magma under the rift valley and microbes, breaking down organic material that falls from higher in the lake. The surface of the lake is 1,460 m above sea level.

Unlike normal biogas, which is produced in anaerobic digesters, organic process plants process biodegradable waste, so at the base of the lake, the biogas contains only 20% methane.

This level is lower than that required even in a Jenbacher gas engine. The plan is to strip the carbon dioxide—which forms the balance of the volume of the gas—using water and then to put the gas into reciprocating gas engines located at discrete power stations on the shores of the lake.

The electricity from the engines will be put directly into Rwanda’s electricity distribution network.