The countries of the East African Rift region hold significant geothermal potential, giving them valuable options for sustainable electricity production and direct use. Harnessing these resources can provide a renewable, affordable and stable energy supply. It can also help countries to fulfil the 2030 Agenda for Sustainable Development and climate goals set out in the Paris Agreement. Despite the region’s economic challenges, plants in Ethiopia and Kenya have attained geothermal power generation capacity of about 900 megawatts-electric (MWe). Exploration drilling confirms untapped resources at both deep and shallow levels across the region. A recent report from the International Renewable Energy Agency (IRENA) – drawing on lessons from the Comoros, Djibouti, Ethiopia, Kenya, Uganda the United Republic of Tanzania and Zambia – offers recommendations to create enabling conditions and fast-track regional geothermal energy development. Presented below are select extracts and highlights from the report titled, “Geothermal Development in Eastern Africa“.
The total installed electricity capacity from all energy sources in the East African Rift countries is about 20 GWe. The contribution of geothermal energy to this is about 900 MWe, with all the existing installed geothermal power plants located in Kenya and Ethiopia.
The first geothermal electricity generation plant was developed in the DRC in 1952, and it had an installed capacity of 0.2 MWe. However, the plant was decommissioned in the 1970s when mining operations for which it was supplying power declined. This was arguably the first binary power plant in the world. Kenya was the second country to install a geothermal power plant with the 45 MWe Olkaria I power plant coming into operation in 1981-1985. The installed capacity in Kenya has since grown to 880 MWe from several sites. Kenya has continued to lead in geothermal development and, in 2017, geothermal represented about 46% of electricity produced in the country against its installed capacity of about 28%. Zambia was the third country in Africa to install a geothermal power plant. The 0.2 MWe ORC pilot plant was developed at Kapisya geothermal area in 1986 but has not been commissioned to date – initially due to the absence of a transmission line, but lately due to a breakdown of the production well equipment (Omenda and Zemedkun, 2011). The status of selected geothermal fields/projects in the region is shown in the table below.
Hydropower and fossil fuels are the only gridconnected sources of electricity in the Comoros Islands. The installed capacity of fossil fuelbased sources remained constant during the period 2010-2019 at 21.6 MWe, and similarly, hydropower capacity remained unchanged at 1.4 MWe. The Comoros Islands had a significant increase in electricity access for urban, rural and national consumers from 2000 to 2019 with an urban electrification rate exceeding 95% in 2017. The national electrification rate was also the highest in the region at 80%, while the rural electrification rate was 74%.
As of 2020, there are no geothermal fields in operation in Comoros. Yet the government has shown commitment towards geothermal exploration and development despite the limited financial resources available in the country. The focus area for geothermal exploration is the Karthala Volcano, located on the main island of Grand Comoro. The other islands have not been evaluated for their geothermal potential.
As of December 2019, the installed electricity capacity in Djibouti amounted to 123 MWe and was mainly from non-renewable energy sources. The installed capacity was almost constant between 2008 and 2019, but this was supplemented by imported electricity from Ethiopia through a 230 kilovolt line constructed in 2011. Djibouti relies on imported energy electricity with about 70% supplied from hydropower by Ethiopia and the rest from diesel-powered generators. Furthermore, Djibouti has an installed off-grid capacity of 0.3 MWe from solar PV. The national electricity access rate in Djibouti increased from about 56% in 2000 to 60% in 2017. However, the rural electrification rate decreased from 56% to 26% during the same period, while in urban areas it increased from 56% in 2000 to 70% in 2017.
As of December 2019, all geothermal projects in the country were being developed by Djibouti Office for Geothermal Energy Development (ODDEG), which is the state entity charged with the responsibility to manage the country’s geothermal resources. However, despite the absence of legislation governing private investment in geothermal energy projects, the Djibouti government through the National Investment Promotion Agency (NIPA) has put in place an interim mechanism to allow IPPs to develop renewable energy projects.
There is no recorded large-scale direct use of geothermal resources in Djibouti, except trapping of steam for water production from steam condensation. However, preliminary studies indicate that there could be potential for direct use in drying fish, aquaculture heating, desalination and space cooling at several sites close to large populations centres. Such sites include Abhe, Allol and Sakalol (northeast of Asal) and Gaggadé to the east. The main technical barriers to geothermal development in Djibouti include extreme salinity of the reservoir fluids, cold seawater incursion into the reservoir, and extremely hot weather conditions. The salinity of the geothermal reservoir in the greater Asal geothermal field exceeds 37 grams per litre (g/L), which presents challenges of aggressive scaling during flashing.
Non-technical barriers to geothermal development in Djibouti are mainly linked to limited human, financial, legal and institutional capacities. Lack of adequate finance to undertake exploration drilling has contributed to the slow development of the projects.
Ethiopia has grid-connected electricity capacity of about 4,525 MWe from hydropower, wind, bioenergy, solid municipal waste, solar, geothermal and fossil fuel-based generators. The installed electricity trend from 2010 to 2019 shows a steady increase in installed capacity between 2010 and 2016 from around 2,020 MWe to about 2,715 MWe, dominated by hydropower. In 2017, the country more than doubled the installed capacity from 2010 when the capacity increased to 4,435 MWe. In 2019, renewable energy sources accounted for about 98% of installed capacity in Ethiopia. Among renewable energy sources, hydropower accounted for about 84%; wind, 7%; and bioenergy and municipal waste, 6% each. In addition to gridconnected electricity, Ethiopia derived about 29.3 MWe of electricity from off-grid solutions consisting of bioenergy (17 MWe), solar (11 MWe), hydropower (1.3 MWe) and wind (0.01 MWe).
Ethiopia is one of the countries in the East African Rift with significant geothermal potential. The most prospective sites are located within the Main Ethiopian Rift (MER). The reconnaissance survey by the Geological Survey of Ethiopia (GSE) started in 1970. Over time, the survey revealed that there are at least 120 hydrothermal sites in the rift valley, of which 24 could be high-enthalpy resources suitable for power generation and direct use. Among the important prospects from south to north are Abaya, Corbetti, Abiata, Aluto, Butajira, Tulu Moye, Gedemsa, Boku, Boseti, Kone, Fantale, Dofan, Arabi, Meteka, Teo, Danab, Damali, Tendaho, Boina and Dallol.
Successful drilling in Aluto-Langano resulted in the development of an 8.5 MWe (7.3 MWe net) pilot power plant in 1998. However, the plant operated only intermittently between 2003 and 2015 due to maintenance challenges. The plant has not been operational since 2015. With funding from JICA, the World Bank, the Scaling up Renewable Energy Program in Low Income Countries (SREP), and the government of Ethiopia, Ethiopian Electric Power (EEP) plans to rehabilitate the plant and expand the project to 70 MWe. In March 2020, EEP signed an engineering, procurement and construction (EPC) contract for the development of the small-scale power plant, which is financed by JICA and expected to be commissioned in 2021.
In 2014, the government opened the sector to private investment, and four private companies were awarded licenses to explore and develop geothermal resources. Corbetti Geothermal project and Tulu Moye Geothermal project are the most advanced private projects, having completed detailed surface studies. The key to the recent acceleration of the two projects has been the signing of power purchase agreements (PPAs) for the supply of 150 MWe each at a total investment cost of USD 1.6 billion. In March 2020, Kenya Electricity Generating Company PLC (KenGen) started to drill exploration wells in Tulu Moye. Ormat is in the final stages of negotiating a PPA with Ethiopian authorities for the generation of 200 MWe. The other prospects under private development are Fantale and Butajira (Cluff Geothermal), Abaya (Reykjavik Geothermal), and Wondo Genet, Boku, and Daguna Fango (OrPower 12, Inc.). These prospects have been explored in detail and drilling sites identified for exploration wells. Financing of the projects has come from owners’ equity and grants from AUCGRMF.
In spite of the low level of utilisation, the country has a large potential for direct use for industrial applications, greenhouse heating, bathing and aquaculture, among others. Utilisation of low-temperature resources for direct use in Ethiopia is expected to see rapid growth with the enactment of the geothermal law as well as the regulations that will promote the development of these resources by communities, regional governments and the private sector (Federal Democratic Republic of Ethiopia, 2016).
Petroleum and electricity are the main modern sources of energy in Kenya. However, energy needs in rural areas and informal urban settlements are provided by wood fuel. Biomass, including wood fuel, contributes about 68% of the total energy consumed in Kenya, with petroleum contributing about 22% and electricity 9%. The installed capacity connected to the grid in Kenya as of 2019 was about 2,850 MWe. Of this, geothermal contributed about 823 MWe. Significant growth in installed electricity capacity from renewables was recorded between 2014 and 2019, driven by growth in geothermal, wind and solar installations. During this period, installed capacity for hydropower remained nearly constant. Non-renewable installed capacity increased between 2010 and 2015 but declined between 2016 and 2019. Renewable energy sources contributed about 75% of the total grid-connected installed electricity capacity in 2019. Geothermal and hydropower were the main sources, each with a 29% share of total installed capacity.
Electricity generation was mainly by hydropower between 2000 and 2014, but geothermal became the foremost source of power consumed in Kenya thereafter. In 2017, the share of electricity generated from geothermal was 46%, hydropower 31%, thermal 21%, and wind 1%. In total, renewable sources of energy contributed about 79% of the electricity consumed in Kenya in 2017.
Monthly electricity generation for January December 2018 shows a trend that mimics the weather patterns. While hydropower generation shows significant reduction during the dry months of December to March, thermal generation shows an upswing to cover for the hydropower shortfall during the same season. Geothermal generally shows a flat pattern due to its baseload nature.
Kenya’s geothermal prospects are mainly located along the Kenya Rift, which is a part of the EARS. The geothermal prospects that correspond to volcanic centres in Kenya are: Suswa, Longonot, Olkaria, Eburru, Menengai, Korosi, Paka, Silali, Emuruangogolak, Barrier, and Homa Hills. Other geothermal prospects, which are not associated with central volcanoes, include Namarunu, Lake Baringo, Lake Bogoria, Lake Magadi, and the Elementaita and Akiira geothermal areas. Some geothermal prospects, such as Mwananyamala and Homa Hills, lie outside of the Kenya Rift valley.
Olkaria III power project was the first geothermal project in Kenya involving the private sector. In 2000, the government of Kenya entered into an agreement with OrPower 4 Inc. after having drilled six wells state resources. The project currently has an installed capacity of 170 MWe of ORC technology. Using wells drilled in the Olkaria fields, Oserian Development Company (Oserian flower farm) constructed two power plants with an installed capacity of 2.4 MWe and 1.2 MWe of ORC and backpressure technologies, respectively. The first power plant was commissioned in 2004 and the second in 2006 to generate power for internal use in the farm. In Eburru, a 2.52 MWe well head power plant was commissioned in 2012 using an existing well with a temperature >285o C. KenGen plans to expand the power plant in stages.
In Menengai, appraisal and production drilling have confirmed steam equivalent of more than 170 MWe, and drilling is continuing in the field. Development of the power plants has however experienced delays due to the complexity in implementing the PPP model adopted. This has resulted in a prolonged process to close the Conditions Precedent (CPs) set out in the Project Implementation and Steam Sale Agreement (PISSA), PPA and requirement by the IPP lenders to enable the IPPs to reach financial close. Geothermal power plants with a total installed capacity of 105 MWe are expected to be developed in Menengai by three IPPs, with the first unit of 35 MWe expected to be commissioned by 2021.
In 2019, two geothermal wells funded by the government and GRMF were successfully drilled in Paka, proving the presence of a geothermal resource in the field. GDC may subsequently drill the fields to full steam status including production drilling or invite private investors to join at production drilling stages and power plant development. Drilling at Korosi and Silali prospects, which are also partially funded by GRMF, was planned to start in 2020.
As for direct use, geothermal heat has been used in Kenya for bathing, crop drying, aquaculture and greenhouse heating. A commercial spa has been developed by KenGen at Olkaria II geothermal field. Furthermore, GDC developed a demonstration facility in Menengai geothermal field to showcase the technical and financial viability of direct use. The facility consists of a geothermalheated greenhouse, geothermal-powered laundry operations, aquaculture pond heating, geothermal milk pasteurisation and geothermal grain dyer.
The successful geothermal story of Kenya can be attributed, amongst other aspects, to strong government support (political and financial) and a well-developed human capacity for geothermal exploration and development. Geothermal will continue to be the leading source of power consumed in the country in the coming years. However, the rate of growth in geothermal power development is expected to decrease due to the current mismatch of electricity supply and demand in the country, where supply has grown at a higher rate than demand. As of July 2019, Kenya was reported to have an electricity grid installed capacity of 2,732 MWe against a peak demand of 1,870 MWe.
This means that the reserve capacity is 46% of the peak demand, resulting in financial constraints to the off-taker. As a consequence, the off-taker, Kenya Power and Lighting Co. Ltd, froze signing of new power purchase agreements in 2019, locking out 23 applications with a combined capacity of 2,240 MWe which were under consideration. However, this oversupply is expected to ease as the government in 2018 initiated the Kenya National Electrification Strategy (KNES) in a push to achieve access to electricity for all in the country by 2022. This is in addition to the Last Mile Connectivity Programme and Slum Electrification Program, which supported the growth of access to electricity in Kenya to the current level of 63% nationally. Furthermore, the government of Kenya indicated its intention to disconnect three fossil-fuelled power plants by 2020 with a total installed capacity of 190 MWe from the national grid. At a regional level, the development of power interconnectors through the power pools will facilitate the exchange of electricity with other countries, further easing the burden of oversupply.
Tanzania has seen slow growth in its grid installed electricity capacity, with expansion from about 1,150 MWe in 2010 to 1,640 MWe in 2018. Hydropower was the main source of electricity between 2010 and 2014, with an installed capacity of about 570 MWe. An accelerated growth in fossil fuel-based generation was recorded from 2015 to 2019, however. During this period, the installed capacity from fossil fuels increased from 520 MWe in 2014 to 1,028 MWe in 2019. The growth in installed capacity from fossil-fuel power plants in 2015 is attributed to expanded capacity to utilise natural gas extracted from the Rufiji basin of eastern Tanzania.
The national electricity access rate in Tanzania has remained low, despite an increase from 9% in 2000 to 32% in 2017. The fastest growth in access rates was for urban centres, which increased from 33% in 2000 to 65% in 2017.
Geothermal resource development in Tanzania is at the exploration stage with reconnaissance and detailed surface studies in the four main areas of interest. These are: the northern volcanic region around Lake Natron; the central region within Tanzanian craton; the southern region around Mbeya; and the eastern region along the coast within the Rufiji basin. Tanzania Geothermal Development Company (TGDC), the state agency in charge of geothermal development, has identified in its strategic plan four projects areas that could contribute to the realisation of the 2025 target of generating 200 MWe from geothermal energy: Ngozi, Songwe, Kiejo-Mbaka and Lake Natron.
Ngozi is currently the flagship geothermal project in the country. Detailed surface studies have been undertaken including geological, geochemistry and geophysical studies, and a conceptual model developed that indicates the possible occurrence of a high-temperature geothermal system. TGDC estimates that the resource could generate more than 45 MWe. TGDC plans to drill two to three exploration slim holes in the Ngozi geothermal prospect down to a depth of 1,000 m to 1,500 m to confirm the existence of a geothermal system with funds from GRMF, SREP and the government of Tanzania.
Kiejo-Mbaka geothermal prospect is located in the southern volcanic region within the Rungwe volcanic field. Detailed studies have been undertaken in the area, and a medium-temperature fracture-controlled geothermal system defined. In the Songwe geothermal area, detailed geothermal exploration studies undertaken in the area suggest a medium-temperature, fracturecontrolled geothermal system suitable for both binary power generation and direct use. TGDC is planning to drill thermal gradient holes to define the resource upflow zones to aid in the selection of suitable sites for exploration wells. It is estimated that the resource at Songwe could support 20 MWe power project and presents a great opportunity for direct use, including for bathing/balneotherapy and crop drying.
There are currently no commercial-scale direct use applications in Tanzania. However, smallscale application are found in the Arusha and Kilimanjaro areas, Songwe, Mbaka fault, Luhoi and Lake Natron. The main direct use application in these localities is bathing, especially for tourism.
In terms of barriers slowing geothermal development in Tanzania, as in many countries in the East African Rift region, limited technical skills and inadequate equipment for geothermal exploration and development are the major factors. TGDC and the Tanzanian government are addressing this by training scientists, engineers and technicians. Since TGDC intends to undertake a portfolio of geothermal projects to achieve the planned generation of 200 MWe by 2025, a large number of personnel will be required to manage all the projects.
The electricity sector in Uganda saw growth, from 630 MWe to 1 179 MWe, in grid installed capacity between 2010 and 2019. The increase in installed capacity was mainly from additional hydropower, solar and bioenergy (Figure 36). Renewables constituted the largest share of grid-connected electricity at 88% in 2019. The installed capacity is primarily hydropower, with a share of 76% in 2019. Bioenergy constituted 7%, while solar PV made up 5%. In addition, Uganda has an off-grid installed capacity of 33 MWe consisting of solar PV (28 MWe) and hydropower (5 MWe).
Geothermal resources in Uganda are all located in the Western branch of the EARS, mainly along the Uganda-DRC border. The main geothermal areas characterised by large hot spring flows are Katwe-Kikorongo (Katwe), Buranga, Kibiro, Panyimur and Ihimbo. Among these, Kibiro, Panyimur and Buranga are at advanced stages of exploration while the others are at detailed reconnaissance phase. The evaluation of the geothermal systems in Uganda revealed that all the systems are fault/fracture-controlled and low to medium temperatures.
The Kibiro geothermal prospect is under development by the Uganda government. Drilling of temperature gradient holes commenced in the first quarter of 2020 funded by the Ugandan government and the GRMF. If successful, the project will be leased to a private developer under PPP arrangement or to the Uganda Electricity Generation Company Limited.
The Buranga geothermal prospect, located in western Uganda, is characterised by hot springs to the northwest of Rwenzori Mountain near the foot of Bwamba escarpment and localised by northeastern trending border faults. The Buranga prospect is licensed to Gids Consult Ltd, which intends to drill thermal gradient holes in 2020 that would lead to drilling exploration wells in 2020/2021.
It is clear that direct use of geothermal resources can create viable economic activities for local communities and the government. The Uganda government is therefore taking a proactive approach by promoting both electricity generation and direct use of geothermal resources through awareness creation and focussed training. The slow progress in geothermal development in Uganda can be attributed to exploration studies which were based on a model of volcano-hosted geothermal systems; lack of sufficient stateof-the-art field and laboratory equipment for data collection, analyses and modelling; lack of supportive policy; and inadequate incentives for private geothermal development.
Zambia has vast hydropower potential estimated at over 6,000 MWe from the main dams. Nevertheless, only about 2,400 MWe is currently installed. The other source of electricity in Zambia is bioenergy, whose status has remained the same since 2010 with an installed capacity of about 43 MWe. Installed capacity from solar has remained very low, while non-renewable sources increased from 80 MWe to 520 MWe between 2010 and 2019 (Figure 40). In addition, Zambia has an off-grid installed capacity of 13 MWe consisting of solar PV (7 MWe), fossil-fuel generation (4 MWe) and hydropower (2 MWe). National access to electricity in Zambia in 2017 stood at about 40%.
With regard to geothermal energy, geothermal surface manifestations have been identified in many geologic environments in the country, ranging from non-volcanic Permian Karoo extensional basins in the south and a late Proterozoic Katangan granitic belt in the north of the country. Hot springs discharge along faults and fractures associated with the development of the EARS at Kapisya, Chinyunyu and Kafue trough. The majority of the hot springs occur within the Luangwa rift, which is a southwestern extension of the EARS. The association of the manifestations with geologic structures, and absence of recent volcanism in the areas, can be inferred to imply that all the geothermal resources in the country are of low- to medium-temperature, fracture/faultcontrolled systems.
Kapisya geothermal field is the best-known geothermal area in Zambia. Hot springs occur over a wide area with a maximum temperature of 85o C recorded in some of the hot springs. Fifteen shallow wells drilled to 200m depths encountered hot fluids of over 95o C, which was considered suitable for binary power generation.
Geothermal resources in Zambia are currently used only on a small scale for direct use in various parts of the country. These include recreation and balneotherapy as well as salt recovery. The main recreational use is at Chinyunyu hot springs area near Lusaka, where there is a hot bath as well as medical use of the hot water.
Building on the analysis of experiences in Comoros, Djibouti, Ethiopia, Kenya, Tanzania, Uganda and Zambia, the IRENA report draws on lessons learned in these countries and makes the following main recommendations to improve enabling frameworks and thereby fast-track the deployment of geothermal energy in the region.
Policies and regulatory framework
» Transparent, clear and predictable licensing and administrative procedures are an essential prerequisite for attracting geothermal developers and investors.
» The establishment of strategic geothermal institutions and departments within energy ministries has been shown to accelerate progress in geothermal development.
» Recent developments in Ethiopia suggest that, with current risk mitigation mechanisms and stable policies, well-structured power purchase agreements can support the early entry of private developers in the financing and implementation of geothermal project.
» Distinct and clear policies and regulations for direct use projects should be enacted.
» Though finances from the public sector have been instrumental in the realisation of geothermal projects in the region, it is desirable that the private sector get involved as early as possible.
» Risk mitigation schemes and financial support may be considered for both power and direct use projects. Public-private well-productivity insurance schemes could complement existing support mechanisms and encourage development.
» Available and forthcoming financing schemes could be used for raising equity to finance geothermal projects, particularly those in early stage development.
» Technical assistance and project facilitation tools are already available in the region but further support may be required to help some project developers access much-needed affordable finance.
» Purchase of capital-intensive drilling rigs by countries may not be recommended during early geothermal development stages but could be considered after successful exploration to help lower the cost of drilling if the local energy landscape is conducive.
Developing direct use projects
» Awareness creation of the potential for direct use and associated benefits should be targeted towards decision-makers, communities and industries. Appropriate tools to assess the viability of direct use projects should be developed.
» Accelerated development of direct use in the region may benefit from master plans for geothermal heat utilisation for each country that are aligned to industrial and rural development strategies.
» Licensing of direct use projects may be streamlined and regulations clearly spelt out.
» Demonstrating the financial viability of direct use projects and the development of suitable business models should be supported.
» Coordination of the activities of stakeholders could result in quicker development
» The appropriate geothermal exploration techniques in the Western branch of the East African Rift will be those focusing on the determination of fault planes and shallow geothermal reservoirs.
» Similar techniques are appropriate for low- to medium-temperature resources in the Eastern branch since most of them are also associated with fractures or fault systems.
The full report can be accessed by clicking here