Proceedings, 8th African Rift Geothermal Conference Nairobi, Kenya: 2 – 8 November 2020

Project for Development of Geothermal Resources in the Ruwenzori Sector, a Preliminary Report

Pacifique S. Mukandala0, Georges M. Kasay 0, 0, Vikandy S. Mambo 0,0 1Department of Geology, Université Officielle de Ruwenzori, P.O. Box 560 2Department of Geosciences, Pan African University of Life and Earth Sciences, University of Ibadan, Nigeria 3Department of Chemistry, Université de Kinshasa Email: [email protected],[email protected] ,[email protected]

Keywords: Development, Geothermal, Resources, Energy, Geology, Hot springs, DR Congo

ABSTRACT

The Ruwenzori sector is located in the North-Kivu province, territory in the eastern part of the Democratic Republic of the Congo (DR Congo) at the border with Uganda. It has several geothermal surface manifestations, mainly hot springs in Mutsora, Masambo, Kikura, Kyavitumbi and Kambo. All these geothermal manifestations have been mapped and are currently under geoscientific investigation. The area also has a large hydrologic network and several other geothermal fields which are yet to be discovered with further research. This paper focuses on reviewing the direct and indirect uses of known geothermal resources from which the local population of the Ruwenzori sector may benefit in the future. Applications related to direct use of geothermal manifestations include greenhouse in agriculture, hot water pool for bathing and medical benefits for tourist and local people, hot water for fish farming and other several applications. Indirect use of geothermal resources would generate energy for local communities and this would allow them to shift from traditional to modern agricultural practices. Electricity would benefit the local people in transforming products such as cocoa, palm oil, maize and preserving other crops after their harvest. The valorization of geothermal resources in the Ruwenzori sector is of paramount importance in support to the development boost, like boosting tourism, and in support of peace restoration in the territory.

1. Introduction The project for development and use of geothermal resources in the Ruwenzori sector/DR Congo is a good opportunity that requires effort, commitment and consent of local and regional governments and partners. The Ruwenzori sector has surface geothermal manifestations. Hot springs are located in Kambo, Masambo, Mutsora and Kikura. The Kikura spring is difficult to explore due to unrest in the area. On one hand, the sector is drained by many rivers and streams including the famous Semuliki River. Nevertheless, a hydropower plant project on the Semuliki River would reduce the normal flow of the Nile Mukandala and al., 2020

River putting in jeopardy several lives which depend on it. Ruwenzori sector faces a lot of challenges in terms of energy and security. People depend on agriculture and small farming for their daily activities. Modern agriculture and farming require electricity. Being at the foot of Mt Ruwenzori, the sector is very attractive to tourists who climb up to the Marguerite Peak, and the rare botanic diversity at different altitudes. This is why developing geothermal resources for different uses such as hot water swimming pools, energy, greenhouses and other important applications would be crucial for the improvement of the sector. The development and use of geothermal resources require an understanding of the geology, geochemistry, geophysics and environmental aspects. Geothermal investigations in the Ruwenzori sector started five years ago. From these studies, it has been shown that many hot springs in these areas have low temperature which ranges between 37 and 57 Celsius degrees. This low temperature has led to suggesting that these spring waters can be utilized directly; however, none activity has been suggested until now. Thus, this work aims to review prospective activities which could be developed from geothermal potentials identified in the Ruwenzori sector. Most of the activities are based on direct and indirect utilization and valorization of geothermal resources. In this paper, we also gather some notes related to the tectonic activity, geochemical and petrographic constraints of the Ruwenzori sector.

2. The energy potential of the DR Congo All sectors of life in the country need energy to function and contribute to the economic growth and improvement of social living conditions of the population. For development specialists, energy consumption is an indicator of the level of development and dynamism of a country's economy. Thus, each country develops its energy policy by ensuring that the availability of energy resources is provided in sufficient quantity to the needs of its users in terms of quality, efficiency and security. It also makes sure that these resources are accessible to them physically and economically (Taty, and al. 2014 not in references). The sources of energy in the DR Congo are abundant and various (table 1), and the potential energy which can be produced by the country is very high. The energy is particularly provided by hydroelectricity in many localities of the country. Although the estimated potential of the Congo River alone is about 100,000 MW, DR Congo has a very low energy distribution and consumption network. This is partly due to poor governance on one hand, and energy transportation to remote places on the other hand. This is why many villagers get their energy from firewood, unfortunately with its related drawbacks to the environment. With population growth, energy needs are increasing. Estimation of energy needs from 2013 to 2025, in the DR Congo, is presented in Table 2. Mukandala and al., 2020

Table 1: Sources of Energy in the DR Congo (after Kabasele, 2016). Energy sources Potential Hydraulic 100,000 MW Wood 1.250 million tons, 122 million ha of the equatorial forest Mineral coal 720 million tons Natural gas 57 billion m3 of methane gas in Lake Kivu Solar To be evaluated Geothermal To be evaluated energy Wind To be evaluated Uranium To be evaluated but 1800 tons identified Oil To be assessed, but 230 M barrels of known reserves

Table 2: Energy demand evolution in megawatts (MW) from 2013 to 2025 (ANAPI, 2016, cited by Makuku, 2019) Province 2013- 2015- 2017- 2019- 2021- 2023- 2025 2014 2016 2018 2020 2022 2024 North-Kivu 55-58 61-64 66-69 72-75 78-81 85-89 93 Maniema 8-8 8-9 9-9 10-10 11-11 12-13 13 Sud-Kivu 31-32 33-34 35-36 37-38 39-41 42-43 45 Equateur 21-22 24-25 27-29 30-32 34-36 38-41 43 Oriental 60-63 65-68 71-74 77-80 84-87 91-95 99 Kasai-West 34-36 38-40 42-45 48-51 54-58 62-66 71 Kasai-Est 46-49 52-56 60-64 68-73 77-83 88-94 101 Katanga 770-799 829-799 826-855 886-918 952-988 1026- 1107 1067 Bas-Congo 101-104 107-110 113-117 120-123 127-131 135-139 143 Bandundu 49-51 54-56 58-61 63-66 69-72 75-78 82 Kinshasa 751-784 819-855 893-933 974-1017 1062- 1158- 1263 1109 1210 Total 1927 2094- 2201- 2385- 2588- 2812- 3059 2115 2291 2484 2698 2933

Regarding the estimations given in table 2, the energy transportation challenges and the drawbacks related to the deforestation on the environment, every part of the country must develop appropriate energy power plants to respond to their growing energy demand. The DR Congo is known to be one of the countries with an important hydrologic network (Figure 1). These hydrologic networks are constituted of rivers, lakes, streams, springs and part of the ocean. Rivers and streams are part of the hydroelectric power potentials. The Ruwenzori sector has some potential for hydroelectric power because of its rivers and streams network. The most important is the Semuliki river which has network water with several other streams such as Karuruma, Kasaka, Kavaetsa, Kyasenda, Kyaviranda, Kanyamahigha, Lula, Lwandumbi, Museya, Musilipa, Mwaghalika, Nzalire, Thako, Thalihya, Vurondo. With all these potential sources of hydroelectricity, Virunga SARL, a company founded and managed by the Virunga Foundation which is related to the Virunga Mukandala and al., 2020

National Park, has already installed two hydropower plants in Mutwanga in the Ruwenzori sector. This is among tremendous advancements of the Ruwenzori sector energy production.

Figure 1: Hydrographic map potential of the DR Congo (Hütz F. and Januar, A., 2008)

3. Geological and tectonic settings of the Ruwenzori sector The Ruwenzori sector is located in the in the East African Rift System (EARS) which is characterized by recent tertiary magmatic extension and volcanism associated with geothermal resources (Wohletz Kenneth and Heiken, Grant, 1992). Several geological investigations have been done in the sector (Bauer et al., 2010, 2015; Delvaux and Barth, 2009; Delvaux et al., 2012; Lavreau and Ledent, 1975; Lepersonne, 1968; Noel, 1981; Michot, 1938; Tanner, 1970, 1971, 1973). Recent geothermal research was done by Mukandala et al. (2018). 3.1 Localization in the Western branch of the EARS The EARS is subdivided into two main branches, the western and the eastern branch (Figure 2). It is a tectonic tear on a lithospheric scale. The geophysics of the rift reveals that Africa individualized during large geological events with modifications of the geomorphology and Mukandala and al., 2020 deep structures. The EARS is an area characteristic of intense earthquakes and volcanism, several faulted structures, tectonic lakes and rivers, intense magmatism and several hot springs (Hirsch and Roussel, 2009). The rift is a permanent active region with active volcanoes in and natural hazards such as landslides and earthquakes (Delvaux and Barth 2009, Delvaux et al. 2012).

Figure 2: Map showing the structure of the EARS (Varet, 2014). 3.2 The lithology of the Ruwenzori sector please include a geological map The Ruwenzori sector appears to consist of two parts: the southern half, which includes the whole part of the massif located to the south of the Butahu and Mobuku furrow, made of allochthonous masses; and the northern half, which is situated in the North of this furrow, a tectonic basement on which the layers evolved (Michot, P. 1938). The Congolese side of northern Ruwenzori, the part of the chain extending north of the Butahu Trench, is an indigenous mass covered by several lithologies. The oldest rocks are cipolins associated with amphiboloschists of sedimentary origin; these layers exist only sporadically, at least throughout the explored part of this unit; they are grouped under the name of "Stanley series." A hornblende gabbro massif which constitutes the whole region is represented today by important parts of Mount Stanley, Wusu-Wameso, Mount Baker, the surrounding of Lamya hot spring and the western border of the region. Dykes of dolerites and diabases are found in the hornblende gabbro. The thermal springs of Kambo, Masambo, Mutsora, Kyavitumbi and Kikura lie respectively Schists, Quartzites, Schists, Quartzo-phyllades and quartzites. Geochemical studies of the rocks of the thermal springs also prove the existence of a volcanic environment in the Mukandala and al., 2020

Ruwenzori area (Mukandala et al., 2018). These rocks are so fractured and we understand the major role of tectonics in the establishment of geothermal deposits. 3.3 Orogeny of the Ruwenzori sector 3.3.1 Wusuwamesian Orogeny The hornblende gabbro intrusion was immediately followed by an enrichment of amphibole. The products have probably been, during the same orogenic period, taken up in a rather superficial folding. The original gabbro exhibited a frank mesozonal consolidation facies, and the products of amphibole enrichment increased in levels. When the structure reached the epizone, dikes of dolerite and diabase were emplaced. This gradual transfer of the gabbroic unit and accompanying sediments, from the mesozone to the epizone, is the translation of the isostatic equilibrium in a phase where the destructive actions of erosion outweighed the building actions. These phenomena mark the existence of the Wusuwamesian orogeny (Delvaux et al., 2009) from which the last phase is marked by the appearance of dolerite and diabase dykes. 3.3.2 Ruwenzorian Orogeny In the structure formed by the lithological elements of the Wusuwamesian orogeny, granite was emplaced during a late phase of a new orogenic period called the Ruwenzorian orogeny. The recumbent folds which are, in the southern half of the chain, the manifestation of this new folding, are piled up on the Wusuwamesian frame. However, in the average aquifer, a large area of quartzites would seem to indicate that at least a part would belong to the Ankole series; in this case, the Ruwenzorian orogeny would be related to the Wusuwamesian orogeny (Delvaux et al., 2009).The table cloths and all the southern cover of the granite are very strongly towards the south. This deformation probably began in the northern region of the chain by a slight bulge in which the granite was put in place. The bulge, in which the granite took place, is the expression of a general tendency of the plastic material to flow along the vertical; this type of deformation has been entirely substituted for the translations of the masses along the horizontal; the recumbent folds have stopped progressing.

4. Status of geothermal exploration and utilization 4.1 General considerations Until the last century, geothermal energy was most often known as a source of heat for spa treatments and baths. The exploitation of geothermal steam for electricity generation began in the 20th century when the first experimental plant was built in Larderello, Tuscany (Italy) in 1904 (Parri and Lazzeri, 2016). A 250-kW geothermal plant was commissioned in 1913. Currently, some 11 GW of geothermal capacity has been installed worldwide, with capacity increasing fivefold over the last thirty years. The development of geothermal energy in the East-African rift valley followed the volcanological reconnaissance phase (Gibson and Tazieff, 1970). The identification of these exceptional characteristics allowed convincing the main part concerned of the interest to undertake the work of recognition and development of these resources. This is what was initiated with the “Bureau géologiques et minières” in Djibouti since 1970, then in Ethiopia and Kenya with the UNDP from 1972 (Varet, 2014).The DR Congo is one of the first African countries to utilise geothermal energy. The first geothermal installation was installed in the Mukandala and al., 2020 country since 1952 and had a production of 0.2 MW at the Kiabukwa geothermal site (Katanga Province) with a temperature of 91°C. The share of geothermal energy in the global energy balance is still relatively low, at around 0.3% and the prospect of 0.5% growth by 2030 in the energy scenario. The importance of geothermal energy generation is also modest compared to other renewable energy sources. Nevertheless, the exploitable geothermal energy potential in some parts of the world is much larger than the current use, offering significant opportunities for scaling up investments (Gehringer and Loksha, 2012). The D.R. Congo is among the countries with great geothermal potential in Africa. However, it remains among the countries with low geothermal development. The eastern part of the DR Congo witnessed the rifting phenomena with the Virunga volcanic mountain range. This range includes eight volcanoes, the Nyiragongo and Nyamulagira being active. The Nyiragongo is ranked among the ten most active and dangerous volcanoes in the world. The Nyiragongo and Nyamulagira are still in permanent activity and are distant of about 10Km. Another volcanism is recognized in the Ruwenzori sector. The activities of the Virunga mountain range and the west branch of the rift are always accompanied by intense seismicity (Figure 3). The country is subdivided into four major seismic branches (Mavonga et al., 2010), which are the South Soudan-the Ruwenzori-the Eduard Lake; the Virunga-- Masisi; the Lake Kivu Basin-the Ngweshe plain-the Ruzizi Plain and the rift area of Lake Tanganyika branches. All the thermal springs in the Ruwenzori sector are located in the most seismic region of the country (South Sudan-Ruwenzori-Eduard Lake region). This area contains the volcanic chains of Virunga.

Figure 3: Seismic map of the Democratic Republic of the Congo from 1910 to 2007 (Mavonga et al., 2010). Mukandala and al., 2020

More than 135 hot springs have been identified in the DR Congo and only around 30 have been explored. Most of them are located in the eastern part of the country along with the volcanic provinces and Rift (Figure 4).

Figure 4: Hot spring map of the Democratic Republic of the Congo (www.se4all_africa.org, cited by Mambo et al. 2012) 4.2 Exploration and use of geothermal resources 4.2.1 Location of hot springs in the Ruwenzori sector Geothermal surface manifestations and especially hot springs have been identified in the Ruwenzori sector, especially within the rift near the border with Uganda (Figure 5). To the current knowledge, 5 hot springs have been identified in the sector but more investigations may reveal other hot springs in the area. Mukandala and al., 2020

Figure 5: Map showing the location of known hot springs in the Ruwenzori sector/DRC.

4.2.2 Petrography and geochemistry Mukandala et al. (2018), characterized the petrography around the three hot springs in the Ruwenzori sector. Petrographic results revealed that the thermal spring of Mutsora spring is surrounded by shales, that of Masambo spring by quartzites and that of Kambo spring by sludge containing mica-schist at the base. Surrounding rocks of Kyavitumbi and Kikura hot springs are still to be determined. However, microscopic rock descriptions suggest that the hot spring of Kyavitumbi is surrounded by quartzites and that of Kikura by sludge. Moreover, the basement formation should be a quartzite. Water chemistry and geothermometry are in the process of being updated. The structural and tectonic aspect remains to be further investigated.

4.2.3 Physical parameters of the Ruwenzori thermals springs So far, only the temperature and pH have been determined for the five thermal springs in the Ruwenzori sector (Table 3). The temperature varies between 37°C and 58°C, whereas the pH is nearly neutral, being slightly over 7. The geochemistry of the springs is still under investigation. Mukandala and al., 2020

Table 3: Physical parameters of the Ruwenzori thermal springs Site Surface temperature pH KAMBO 37°C 7.2 MASAMBO 52°C 7.8 MUTSORA 43°C 7.7 KYAVITUMBI 54°C 7.6 KIKURA 38°C 7.4

4.2.4 Current usage Currently, direct use of hot water is done in all sites for baths and especially by farmers after their daily activities. Apart from Masambo, where a few fish ponds have been organized, geothermal resources and their benefits are still unknown in the region and this has led to a minor or even no interest from the local community. It is also important to mention that no important infrastructure for direct use has been installed. Only a few scientific and conference papers have been done to understand the geological and geochemical characteristics of these hot springs.

5. Prospects and opportunities In the future, research may be oriented towards tectonics, environmental aspects and geophysics. And it is subsequently that researchers will consider modern trials of direct use of geothermal potentials in the area. As the Ruwenzori sector is frequently visited by tourists who want to see the Mt Ruwenzori and the Virunga National Park, thinking of direct use of hot water from the hot springs would be something that will generate interests as well as visibility of the area in terms of geothermal benefits. It would also allow the local community to understand geothermal manifestations and energy better. From the current knowledge, only direct use would be appropriate for the Ruwenzori sector. Therefore, the need would be to extend researches on geothermal potentials of the DR Congo and determine the capacity of each source and know which one can generate direct or indirect uses. This will need substantial equipment, funds and most importantly the government will. The energy sector in the DR Congo is liberalized and welcomes any interested investor either private or public who would be willing to invest in this sector. From this aspect, enhancing geothermal exploration and exploitation would be a great opportunity which will allow the Beni territory to attract more industrial investors for its agricultural richness that includes maize, cocoa, palm oil and other important crops which need energy for local transformation. The local transformation will boost and improve the economic as well as social living conditions of the local community and this would surely restore peace in the area. We could start with the Mutsora thermal spring which is close to the tourist site for visitors near the Virunga National Park and those who climb Mount Ruwenzori. A swimming pool can be built in such a way that it is supplied with hot water by the thermal spring. This will constitute a new attraction for tourists as an ideal place to relax after a trip to the park or on the mountain and/or even before according to their preference. The Virunga National Park station is localized at 3km from the Mutsora thermal spring.

Mukandala and al., 2020

6. Conclusion In terms of energy, the Ruwenzori sector has several rivers that can intervene in the energy production of the area. It is also under equatorial and tropical climate favouring solar and wind energy. The production of hydroelectricity would destabilize the normal flow of the Nile River as indicated in the literature. However, it is still possible to get energy from rivers and streams in the region. Nevertheless, the development and use of geothermal resources in the Ruwenzori sector is still important concerning the experience of the local community. Direct applications of geothermal resources in the sector will favour the expansion of tourism and will improve agriculture in the sector by using greenhouses and hot water pipes circulation. Indirect applications which include the generation of electricity will allow the local transformation of agricultural commodities and will generate job opportunities. This will also affect agricultural productivity. Thus, the geothermal resources development in the Ruwenzori sector is very important to the local and regional scale.

ACKNOWLEDGEMENTS

We are grateful to the -based “Comité de Pilotage des Ressources Geothermiques du Nord Kivu”, which is pioneering the valorization program of geothermal resources in DR Congo. We also appreciate the constructive comments of the reviewer, Mrs. Lucy Njue.

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