Africa is the continent with the highest solar energy potential in the world. The International Renewable Energy Agency (IRENA) estimates the solar energy potential of the African continent at 60 million TWh per year, compared to 3 million TWh per year for Europe for example. The countries of North and Southern Africa are the most favored on the continent. The solar potential is also considerable in East Africa, the Horn of Africa and the Sahel. While the solar potential is more reduced in Central Africa, due to its equatorial climate and its ecosystems dominated by forests that reduce the penetration of sunlight.
While the potential of the African continent remains largely under-exploited, many efforts are being made to facilitate and accelerate the deployment of solar power generation facilities in Africa. For example, South Africa has 2,323 MW of installed solar capacity, according to Power Africa, thanks to a policy that encourages investment by independent power producers (IPPs). With the gradual decline in the cost of operating solar power, Irena estimates that Africa could acquire 70 GW of installed solar capacity by 2030, provided that policies favorable to renewable energy investments are put in place. Currently, the continent has an installed solar capacity of 12 GW according to the analysis firm Rystad Energy.
Technologies used in Africa
Among the solar energy production technologies implemented in Africa is thermodynamic solar. In a concentrated solar power (CSP) plant, mirrors capture the sun’s rays to generate very high temperatures, between 400 and 1,000°C. The heat thus produced is used to transform water into steam in a boiler. Under pressure, the steam turns a turbine that drives an alternator. It is this equipment that produces an alternating current.
There are three types of solar thermodynamic power plants in the world. In the case of a power plant with a cylindrical collector, long mirrors rotate around a horizontal axis to follow the path of the sun. The rays are concentrated on a tube in which the fluid circulates to transport the heat to the plant. In the parabolic trough technology, the solar radiation is concentrated on the focal point of adjustable parabolas in which mini power plants are located. In the tower power plant, a field of steerable mirrors on the ground reflects the sun’s rays onto a boiler located on top of a tower.
Kathu CSP (100 MW) in South Africa © Engie
Because of the costs involved in installing these technologies, very few concentrated solar power projects are currently being implemented in Africa. Existing or under construction power plants are mainly located in South Africa and Morocco. In Nelson Mandela’s country, the French IPP Engie operates the Xina Solar One plant and the Kathu plant, each with a capacity of 100 MW. The Saudi IPP Acwa Power operates the 50 MWe Bokpoort CSP. In the Cherifian kingdom, the Saudi company has built several power plants of this type within the solar complex of Noor Ouarzazate of 580 MW.
Solar photovoltaic
More common, photovoltaic power plants are equipped with several solar panels. In such an installation, the solar panels capture the sun’s rays. Under the effect of sunlight, the silicon, a conductive material contained in each cell, releases electrons to create a direct electric current. The inverter transforms this direct current into alternating current so that it can be more easily transported by the grid’s medium-voltage lines.
Solar megaprojects on the continent
Photovoltaics is the most developed technology in Africa, from large-scale, grid-connected power plants to solar home systems. This technology is at the heart of mega-projects to exploit solar energy in Africa. This is the case in the Benban solar complex, located in the governorate of Aswan in Egypt. It is a mosaic of 32 solar power plants entirely financed and built by IPPs. The complex will be commissioned in 2019 with a capacity of 1,650 MWp.
Although the Moroccan authorities are behind in its implementation, the Noor Ouarzazate solar complex is among the major solar projects developed on the African continent, with a current installed capacity (including photovoltaic and CSP) of 580 MW. The implementation of this project is part of the Moroccan government’s plan to produce 52% of the electricity consumed in the kingdom from renewable sources by 2030.
The commitment of development partners
Two development financing institutions want to rely on solar energy to accelerate the electrification of Africa. This is the case of the International Finance Corporation (IFC) of the World Bank Group, which is expanding its “Scaling Solar” program. This program implemented globally allows the rapid installation of solar power plants through public-private partnerships (PPP). For the moment, “Scaling Solar” is being deployed in Senegal, Ivory Coast, Ethiopia, Madagascar, Zambia and more recently in Niger.
In addition to its investments in solar power plants throughout Africa, the African Development Bank (AfDB) is focusing its efforts on the Sahel, which it wants to make the largest solar energy production area in Africa, through its “Desert to Power” initiative. The program, which is entering its development phase, has already received $150 million in funding from the Green Climate Fund (GCF) for its “Desert to Power G5 Sahel” facility. The AfDB is targeting an installed solar capacity of 10,000 MW in the Sahel, equivalent to the electricity production of a country like Morocco, which currently stands at 10,627 MW according to the Office National de l’Electricité et de l’Eau Potable (ONEE).
On October 20th, 2020, the International Solar Alliance (ISA) announced a partnership with Bloomberg Philanthropies to mobilize $1 trillion in investment in solar power generation worldwide. This program involves the 80 member countries of the organization, most of which are in Africa.
Decentralized solar energy or the key to rural electrification in Africa?
The development of solar energy in Africa is also driven by decentralized systems generally financed and installed by private companies. These solutions are composed of solar home systems. This small electrical network on the scale of a house is composed of one or more solar panels, inverters and batteries for electricity storage. The clean electricity stored in this way is redistributed on demand in the domestic network during the night or in bad weather.
The distribution of its equipment is facilitated by the pay-as-you-go system, whose main payment method is mobile money, a cell phone banking service available throughout sub-Saharan Africa, even in the most remote areas. Increasingly, solar home systems are being accompanied by other services, including internet and television. This equipment is having a real impact on rural electrification. Recently, the American company d.light reported that its solar kits are providing access to electricity to 100 million people worldwide, most of whom are in Africa. In addition to solar home systems, some companies provide complementary solar kits, including solar lamps and lanterns.
Mini-grids also enable rural electrification. These are small solar photovoltaic power plants with electricity storage systems using batteries or hybrids with generators. These installations are equipped with small distribution networks capable of supplying a community or a village. Later, if necessary, the mini-grids can even be connected to the central grid. But in the Democratic Republic of Congo (DRC), the company Nuru is already deploying mini-grids of more than 1 MW that supply entire cities, such as Goma, the capital of North Kivu province.
A solar off-grid in the city of Goma in DRC © Nuru
In Nigeria, the most populous country on the continent (more than 206 million inhabitants in 2020, editor’s note), the authorities are relying particularly on mini-grids for the implementation of an ambitious rural electrification project (NEP) supported by the World Bank and the AfDB. Within this framework, the Rural Electrification Agency (REA) is promoting the establishment of solar mini-grid providers by setting up a performance-based subsidy (PBG) system.
In addition to these ground-mounted systems, other operators have specialized in the installation of containerized solar mini-grids. This modular solution is easy to set up since the main components are prefabricated before being transported by sea container.
What about solar energy for productive use?
Productive solar energy systems are part of the off-grid solutions deployed to power commercial and industrial customers. In most cases, the company receiving the solar energy does not invest anything, but simply pays bills for electricity consumption to the supplier who installs the system. This is known as “solar leasing” and is particularly popular in countries such as Nigeria, Ghana and Kenya.
These decentralized solar systems are seen as an effective solution to load shedding or to reduce the gap between rural and urban areas in terms of access to electricity. At the moment, nearly 600 million Africans are still waiting to get access to electricity.
Jean Marie Takouleu