For decades, Rwanda’s 80 km long Lake Kivu, with its high concentration of methane and carbon dioxide, has been seen as a risk due to its potential for toxic release.
Extracting methane from the lake will now reduce environmental hazards while bringing electricity to millions of people.
At the end of May 2015 US energy developing company ContourGlobal made a big step forward with its KivuWatt energy project by anchoring platform in Lake Kivu, 13 km from the shore.
This successfully completed the construction and installation stage, making the plant ready for the trial stage, which started in September 2015. That is when the plant started extracting natural methane gas from 350 meters in the lake and piping it to the biogas plant on the banks of Lake Kivu.
In its first phase, which was completed in December 2015, the plant powers three generators to produce 26 MW of electricity for the local grid. The next phase will deploy nine additional generators at 75 MW to create a total capacity of over 100 MW. Phase 2 will increase Rwanda’s current installed energy capacity – around 183 MW – by more than 50%.
In terms of technological innovation the KivuWatt project is one of its kind. It is the only gas/water extraction application worldwide, where gas-laden waters are brought from 35 bar pressure to 2 bar into a gas separator where gas bubbles will be extracted from water.
Raw gas will then be washed in four wash towers, leaving clean methane gas to be transported to the power plant through a submerged, floating pipeline. At the power plant combustion engines will generate electricity to be supplied to the Rwanda energy grid.
With KivuWatt, Contour Global it setting new standards in energy production on the African continent. The project is an example of CG’s commitment to technological innovation, as well as a gateway into the Rwanda energy market with a unique project and energy source.
Rwandan energy production is still very low; with an economy growing 5-7 percent annually and a 100-200 MW power deficit, the country is a promising investment destination. By boosting its overall generating capacity by 20 percent in Phase 1, the plant will significantly improve Rwanda’s energy supply.
In addition to its impact on the Rwandan economy, the KivuWatt plant will be life changing for Rwanda’s people, giving millions of them access to the power grid. 75 percent of Rwandans currently live without electricity.
With its KivuWatt project, ContourGlobal is setting a “model for successful power-producing projects in Rwanda and other developing countries,“ says World Watch Institute.
ContourGlobal has invested close to $ 200 million in Phase 1 of the project and will invest another $ 400 million in Phase 2, creating hundreds of employment opportunities for the local community. Phase 2 is expected to be fully operational in 2020.
In the future most of the jobs will be taken over by local managers, technicians and labour. At fully operational Phase 2 , 250 permanent employment opportunities will be available in Kibuye with KivuWatt and hundreds more indirect jobs will be created to support the activities.
The power plant will also bring more safety to the local people as possible eruptions in the lake can be mitigated by the reduced gas pressure resulting from methane extraction.
55 % of the KivuWatt project is financed by ContourGlobal, the other 45 % with funds from the African Development Bank and European finance partners. Contour Global has signed a 25-year concession on the resource site and power purchase agreement with Rwandan electricity utility Rwanda Electricity Group (REG).
Since going into commercial operation, KivuWatt has been able to produce electricity according to the dispatch orders from EUCL with very high availability, most of the time producing full 26MWcapacity to the grid.
Gas production on the extraction platform has worked reliably without any major issues, even exceeding the expectations. Operators have been fine-tuning the gas production and main emphasize has been on lake monitoring activities and to learn the interaction between process parameters and recharge plume behaviour.
Water from the 350 meter depth is returned back to 240 meters after extraction of methane, forming initially a discharge plume which then dilutes into the surrounding water. Wash water from washing process is returned to 60 meters and is settling down before fully diluting and disappearing.
Lake monitoring is following the behaviour of these plumes. In design stages, computer simulations were done to predict the plume behaviours and now lake monitoring is assessing the real movements of the plumes.The lake behaviour has been to large extent without any surprises, and as predicted in design simulations. In the early months, lake monitoring and process data sharing with government’s Lake Kivu Monitoring Project has been intense.
As the lake naturally changes its characters in respect of oxygen layer according to seasons, the lake monitoring activities will continue with high intensity to complete the full annual circle. The information of these activities will also be shared with several scientific studies ongoing or to be commissioned to better understand the lake properties and thus guide the future development of gas extraction at the lake.
The conclusions of the lake monitoring will also guide the final design of Phase 2 of KivuWatt, which is due to commence early next year and be fully operational in 2020.
As KivuWatt is the first full scale gas extraction facility and unique in world scale, it has attracted plenty of interest in international press and media. Several articles have been published in all continents in scientific publications and general press, as well as in TVs and web medias.
National Geographic Explorer and the BBC had their teams at KivuWatt extraction platform some weeks back and their programs are expected to be aired later this year at their channels internationally. All this publicity will bring to wider public knowledge the achievements of KivuWatt but also the development happening in Rwanda, and the uniqueness of Rwanda’s development during past 20+ years.
The added electricity from KivuWatt will make it possible to realize some of the development plans which have been postponed in absence of sufficient and reliable, affordable electricity.