Jenbacher gets into deep water in Rwanda

Symbion Power has chosen Clarke Energy, supplying GE’s Jenbacher gas engines, as preferred bidder for two unusual Lake Kivu power projects in Rwanda. These projects together will employ 25 Jenbacher gas engines from GE’s Distributed Power business.

Clarke Energy will deliver the GE J620 3 MW gas engines to Symbion’s Kivu 56 and KP1 power plants, which are located on the shores of Lake Kivu. Clarke Energy will create jobs in Rwanda to support the maintenance and servicing of the engines.

Symbion Power is an independent power producer that has secured the rights to deliver the two projects on the lake. The first, ‘Kivu 56’, is planned to export 56 MWe into the Rwandan grid under a 25 year concession. The second builds on an earlier pilot project in the same location, KP1. Symbion has acquired the plant and will upgrade it from 3.6 MW to 25 MW, which will be delivered to the Rwandan grid system under a separate 25 year concession.

Symbion Power’s founder and chief executive officer 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 plants at Lake Kivu will increase capacity by 81 MW and significantly reduce the current cost of generation in Rwanda.”

UK based Clarke Energy’s managing director in Africa Alan Fletcher said, “We are delighted to have been named the preferred bidder ... for these two key projects on the shores of Lake Kivu. Our proposed solution is able to deliver reliable supplies of sustainable energy and support jobs in Rwanda and the United Kingdom.” The announcement coincides with a British government trade delegation visit to Africa.

Creation of the biogas

Lake Kivu, one of the African Great Lakes, is a unique body of water because water at its greatest depths is saturated with biogas that is a combination of methane and carbon dioxide. This gas is produced from the unique combination of the pressure at 500 metres depth, combined with heat originating from the magma under the rift valley and the action of microbes, which break down organic material that falls from the upper levels of the lake. The surface of the lake is 1460 m above sea level.

Unlike conventional biogas, which is produced in anaerobic digesters, organic process plants are working on biodegradable waste, so near the bed of the lake, the biogas contains only 20 % methane. This level is lower than that required for 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 feed the gas to reciprocating gas engines located at discrete power stations on the shores of the lake.