Contents lists available at ScienceDirect Renewable and Sustainable Energy Reviews journal homepage: www.elsevier.com/locate/rser Concentrating solar power technologies for solar thermal grid electricity in Nigeria: A review Olumide Ogunmodimu a , Edmund C. Okoroigwe b, ⁎ ,1 a Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, Cape Town 7701, South Africa b Energy Research Centre, University of Cape Town, Private Bag X3, Rondebosch, Cape Town 7701, South Africa ARTICLE INFO Keywords: Concentrating solar power Solar electric power plant Nigeria Direct normal irradiance Renewable energy Solar power ABSTRACT Grid electricity generation in Nigeria has been unstable for a long time now. With respect to her continued dependence on oil and gas and seasonal variations on water level for hydropower, immediate reliable and steady electricity generation in the country is not guaranteed. Incorporating alternative source of energy like solar is a solution. Solar Chimney technology is not yet technically and economically mature, as investment on it is still low, thereby posing more financial risks at least at the megawatt capacity. Photovoltaic and Solar Thermal technologies are technically and economically more established, but they can only ensure 24-h power supply with the aid of energy storage systems. Solar thermal value addition is on its propensity for thermal energy storage and hybridization with liquid fuels at commercial capacity. Hence, due to technology advancement and the country's high direct normal irradiation potential, concentrating solar power is the more suitable solar power technology for commercial electricity generation in Nigeria. In this paper, concentrating solar power technol- ogies are analysed under operational, environmental and social conditions in Nigeria using data from desktop survey to determine the most suitable technology for solar thermal electric power plant. It is observed that the technical maturity of parabolic trough concentrator distinguishes it for preference to all other technologies and would exert moderate pressure on land requirement even though, it is the most expensive and water demanding technology. In terms of unit cost of electricity and water usage capabilities, parabolic dish concentrator is least expensive and uses least water but lacks proven commercial application. Solar tower is technically simpler and possesses better thermodynamic properties than the rest but its low installed capacity increases its financing risk. Hence, the trough system is the most suitable for immediate and medium term projects given its proven tech- nology maturity and flexible financing mechanism. 1. Introduction In the face of challenges of electricity generation, transmission and distribution in Nigeria, alternative sources of electricity to the con- ventional gas fired and hydropower plants in the country are being explored. Solar thermal power will be the promising source of sus- tainable and reliable alternative source of electricity in the country as has been proven in many countries of the world. Concentrating solar power (CSP) or solar thermal electricity projects are not beyond the reach of developing countries like Nigeria and the rest of sub-Saharan Africa, if there is a strong political will by the governments and in- vestors to build the plants even though they are capital intensive. However, prior to the commencement of such projects, energy stake- holders, namely the government, investors, researchers and indeed the general public should understand the fundamental issues to consider in the choice of any type of CSP technology to adopt for the project. Of the many studies on renewable energy and solar thermal technologies in the country, limited attention has been given to the topic considered in this paper. The objectives of this paper are i) to review the progress in the development and use of concentrating solar power (CSP) and other solar-to-electricity conversion tech- nologies, ii) to provide data on the solar resource of Nigeria, water and land availability in the northern part of Nigeria and iii) To provide a guide on the selection of a suitable CSP technology for a short and medium term scalable solar thermal electric power plant (STEPP) in Nigeria based on the level of development, tech- nical, economic, social and environmental requirement of each https://doi.org/10.1016/j.rser.2018.03.029 Received 10 May 2016; Received in revised form 26 February 2018; Accepted 14 March 2018 ⁎ Corresponding author. 1 Present address: Department of Mechanical Engineering, University of Nigeria, Nsukka 410001, Enugu State, Nigeria. Tel. +2348064879825 E-mail addresses: OGNOLU@myuct.ac.za (O. Ogunmodimu), edmund.okoroigwe@unn.edu.ng (E.C. Okoroigwe). Renewable and Sustainable Energy Reviews 90 (2018) 104–119 1364-0321/ © 2018 Elsevier Ltd. All rights reserved. T