Keywords: Geothermal energy, Cameroon Volcanic line, thermal springs.
Geothermal energy is the thermal energy in the earth’s crust that arises from the radioactive decay of minerals and solar energy absorbed at the surface . Africa is currently undergoing a period of economic development. To be sustainable, such development requires a large investment in the renewable energy sector . Cameroon is particularly unique in west-northern Africa for its active volcanic line that is a favourable zone for the production of power from geothermal resources . The country has good electrical potential, given the number of hydroelectric dams and power plants throughout the territory . However, the electricity company has failed to align supply with demand for electricity in the country. Hence, there is a need to find new solutions to facilitate access to energy and guarantee that such access is sustainable.
The presence of strong thermal surface manifestations occurring in the form of hot springs, altered grounds, fumaroles, anomalous boreholes and frequent eruptions of Mount Cameroon is an indication of its enormous geothermal potential, which is widely spread along the Cameroon Volcanic Line (CVL). A spring is characterized as thermal when its temperature is above the mean temperature of 23°C, from this definition one hundred and thirty thermal springs have been recorded concentrated along the CVL . However, the current data available includes a full investigation of only 40% of the Cameroonian territory. The thermal spring with the highest temperature that is 74°C was recorded at Woulndé, which is located in the Centre region of Cameroon, and the Lobe spring located at  the base of Mt. Cameroon with a recorded temperature of 49°C . The region of Adamawa has the largest number of thermal springs. These hot springs are distributed along the CVL as follows: Laopanga and Katil near Ngaoundere, Dimple near Foumban, Nilli near Mount Oku, and Lobe near Mount Cameroon. In and around the massive of Manengouba other springs are found in Ahio, Bare, Ndibisi, Nsoung, Ngol, and Melong , besides several other springs distributed around large valleys in the West region. These manifestations indicate the presence of a huge geothermal energy resource potential for both electric and direct (non-electrical) utilization in the country.
Geothermal energy as an electrical source of energy in Cameroon could be used in the locality of Woulndé, where the temperature reaches 600°C at a depth of 1000 metres which is enough to construct a power plant with a capacity 5MW . Also, geothermal heat pumps (heating and cooling system) which are highly efficient renewable energy technology, could be used as an ideal method to satisfy energy demands for cooling and heating spaces and building in the whole of Cameroon, especially in the northern part of the country.
Heating of greenhouses can be implemented in the geothermal areas of Cameroon; it could assist in controlling relative humidity, especially the early morning hours when humidity tends to rise. By reducing relative humidity below 85%, it will eliminate fungal infection and hence avoiding the use of chemical fungicides on plants . Also, heated water could be used to sterilize water used in fertilizers. This will greatly impact foodstuff production since most crops especially in the northern part of the country are attacked by insects and fungal infections.
Geothermal energy could be used to dry potatoes, coconut, meat, onions, garlic, fruits, lumber, spices, sugar, concrete blocks, and a range of other products in Cameroon . Crops are traditionally dried using solar radiation in Cameroon but farmers encounter heavy crop losses due to the unreliability of solar energy during the cold and rainy seasons and at night when the temperature drops. This energy (heat) source presents advantages such as the elimination of fuel costs related to fire tube boilers and heaters and decrease the risk of fire by reducing the need for combustion.
Other applications of geothermal energy come from geothermal aquaculture projects. Several geothermal sites can be selected to raise aquatic species that do not exist in most parts of the country such as tropical fish, carp, catfish, bass, tilapia, salmon, trout, mullet, sturgeon, lobsters, crayfish, crabs, algae, prawns, shrimp, mussels, scallops, clams, oysters and abalone .
The use of geothermal energy among other renewable sources is urgently needed to reduce dependence on conventional energy sources, and will lead to sustainable and environmentally sound development. The direct effect of the development of geothermal energy in Cameroon will be the creation of jobs and growth of sectors such as agriculture, fishing and breeding activities. Nevertheless, geothermal energy exploitation in Cameroon faces many challenges and obstacles despite the presence of volcanic activity and geothermal manifestations. Among the main barrier identified, there are inadequate policy, regulatory and institutional framework, technology limitations, funding constraints, unawareness of investors, inadequate skilled workforce and training institutions . Also, the contribution of geothermal energy today remains negligible because of the low prices and availability of natural gas and fuel. But this situation will not last, considering the gradual increase in prices and demand for energy. So, the authorities should take increasing awareness of the need to diversify sources of energy and preserve the environment.
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Author : Ngassa Lavoisier