Powering the continent: Concentrated Solar Power in Africa

This post is the second in a brief series of articles, reviewing the status of various power generation technologies in Africa, their current status of deployment, cost competitiveness and long term potential to contribute to powering the continent.

There are two main types of solar power generation - Solar Photovoltaics (PV) and Concentrated Solar Power (CSP). PV generates electricity via direct conversion of sunlight in to electricity by photovoltaic cells (i.e. conduction of electrons in semiconductors). PV is the commonest type of solar technology with approximately 134GW of capacity installed worldwide as at the end of 2013 (we discuss the current status and long term potential of PV in Africa in a future post).

CSP technologies use mirrors to concentrate the sun’s rays to heat water and generate steam. The steam is then used to drive a steam turbine to generate power similar to conventional power plants. The steam can also be used in process heat applications such as injection to oil wells to enhance oil recovery, water desalination, cooling, or industrial processes.  As at the end of 2013, there were approximately 3.6GW installed worldwide.

Technology description / illustration of solar CSP system

Source: SBC Energy Institute, Concentrating Solar Power, June 2013

CSP electricity generation is similar for the power block to conventional thermal generation, making CSP well-fitted for hybridization with complementary solar field and fossil fuel as the primary energy source.  In fact Africa is a pioneer in this type of CSP power generation – there are three hybrid solar power plants that combine conventional gas power plant and a solar field to heat steam (called Integrated Solar Combined Cycle plant (ISCC).

There are four main types of CSP technologies - described below: Solar tower; Linear Fresnel; Parabolic Trough and Stirling Dish technology.  These are briefly discussed below.

Source: SBC Energy Institute, Concentrating Solar Power, June 2013

CSP installed capacity and projects under construction in Africa.

There are at least ten CSP projects installed or under construction in Africa – with a total capacity of 530MW concentrated in four countries (South Africa, Morocco, Algeria and Egypt) as shown. 

Cost competitiveness of CSP systems and comments on its long term potential inn Africa

One of the main reasons, CSP is not widely deployed is its costs. As shown below, it is much more expensive than other power technologies with equal promise in the continent. At a levelised cost of $243/MWh, it is considerably more expensive than hydro at $84/MWh or solar PV at $130/MWh (EIA).

Moreover, unlike PV which has seen capacity deployment and consequently, significant cost reductions from economies of scale - CSP deployment remains small.

Source: EIA, Levelised Cost of New Generation Resources in Annual Energy Outlook 2014, April 2014

However, the advantage of CSP is its storage ability. Thermal storage is relatively easy to integrate into CSP projects, and allows CSP plants to smooth variability, to firm capacity and to take advantage of peak power prices. CSP also offers a lot more opportunities for localization and manufacturing of components. 

In summary, good potential, but given current costs, we don't think we'll see many new projects beyond those listed (maybe the odd one or two projects to provide diversity to renewable deployment).