Super Grids in Africa - Could they release the economic potential of concentrating solar power? M AST E R T HESIS M E RC È L ABORDENA September 2013 Thesis supervisors: Prof. Anthony Patt, International Institute for Applied Systems Analysis Prof. Mark Howells, Royal Institute of Technology Department of Energy Technology Royal Institute of Technology Stockholm Abstract Abstract The way its future power systems are designed will have significant impact on sub-Saharan Africa's (SSA) aspirations to move from low electricity consumption rates to enhance life quality and further increase economic opportunity. At present, Africa is experiencing higher economic growth rates than other continents (including Asia). And so is its need for electric power. However, all too often the options that are chosen are the ones with lowest risk and that require little coordination. In part, this is because region-wide planning, coordination and institutions are in their infancy. “Low risk” power plants typically include oil generators that can be sited close to loads, other fossil fuel power plants, and hydro plants that can easily be connected to the continent’s grid. However, hydropower production has been limited due to changes in weather and climate and socio-economic impacts (Collier, 2011). Additionally, its potential has also not been reached as large sites are far from adequate grids. A restructuring of the energy system that considers both the potential for increased geographical integration while moving gradually towards more sustainable electricity generation may hold significant promise. This work considers the potential of another renewable technology namely concentrating solar power (CSP) and connecting supply and demand centers via high voltage direct current (HVDC) power lines. Specifically, the focus is on utility-scale solar power generation to supply the needs of growing urban centers of demand. It develops a Geographic Information System-based (GIS) model with a spatial resolution of 30 arc-seconds to calculate the cost evolution of the electricity produced by different technologies of CSP plants and the costs of grid development to selected centers of demand. The results show that major SSA metropolis can benefit from distant CSP economically attractive to compete with inlaid coal-based generation. In 2010, total imports of coal exceeded 1.4 million short tons with consequent economic and environmental costs. Solar towers plants endowed with thermal storage may become a leading technology for smoothing purposes with zero fuel costs. Furthermore, Africa’s vast solar resources are far from urban centers of demand and a transmission system capable to integrate high levels of renewable energy while improving reliability of supply is required. The results of this study point to the importance of SSA centers to rely on a Super Grid approach to take advantage from CSP least-cost potential and to discontinue expensive traditional sources. Overall, solar corridors can integrate with geographically-wide wind and hydro potentials to create clean energy corridors and encourage a transition towards more sustainable energy systems. Key words: Concentrating solar power, HVDC, Sub-Saharan Africa 2 Preamble Preamble Acknowledgements The completion of this master thesis would not have been possible without the support of many people. First, I would like to express my sincere gratitude to Prof. Dr. Anthony Patt for his trust, warm welcome and his most valuable advice. My special thanks go to Prof. Mark Howells for sharing his long-term experience in African energy systems and for the devotion to his students. Additionally, I would like to thank his colleagues Mr. Sebastian Hermann and Mr. Dimitrios Mentis for their comments and technical review. It is a pleasure to thank Dr. Morgan Bazilian and Dr. Holger Rogner for giving an expert’s opinion on this thesis. Finally, I would like to express my gratitude to my colleagues at the International Institute for Applied Systems Analysis. It was a profound pleasure to work with them and to participate in their inspiring and knowledgeable discussions. 3 Preamble Notations and Conventions Country names and the composition of geographical areas follow those presented in “Standard country or area codes for statistical use”, available at: http://unstats.un.org/unsd/methods/m49/m49.htm. Names of cities or urban agglomerations are presented following the names used by National Statistical Offices or the United Nations Demographic Yearbook. When necessary, the administrative subdivision to which a city belongs is added to the city name to identify it unambiguously. Data collection This study is based on current and public accessible documents. When required, data was collected through requests and personal communication with relevant specialists. The following procedure was used to decide which data use when competing data was found: Where possible, international databases were used, such as EIA, OCDE Factbook, the World Bank and the African Development Bank Group. For electricity access and energy access targets, country data reported in IRENA was used. For electricity consumption and electricity shares, data reported in the EIA was used as it is the most transparent and complete in terms of accessible country time-series data. For population and development figures, the Department of Economic and Social Affairs (Population Division) data from the United Nations was used. When country data was not available from international or national statistical sources, data was obtained from government websites, regional intergovernmental bodies, policy documents and other reports. Most of the African sub-regions have carried out energy forecasts with projections normally based on studies conducted at national level. Regardless of forecasting methods that may vary considerably among countries, the regional plans and related documents entail a wealth of information that was utilized in this study. 4 Table of Contents Table of Contents Abstract 2 Preamble 3 Acknowledgements ......................................................................................................................... 3 Notations and Conventions .............................................................................................................. 4 Data collection ................................................................................................................................. 4 Table of Contents 5 List of Figures 7 List of Tables 9 1 Introduction 11 2 Energy problem in sub-Saharan Africa 14 2.1 Energy demand and consumption patterns .......................................................................... 14 2.1.1 Investment to improve electricity access ..................................................................... 15 2.2 High costs of electricity generation ..................................................................................... 17 3 Energy sector in sub-Saharan Africa 20 3.1 Overview of the energy sector in SSA countries ................................................................. 20 3.1.1 Sub-Saharan Africa unexploited renewable resources ................................................ 22 3.2 Power sector reform in progress .......................................................................................... 22 3.2.1 The promise of regional power trade .......................................................................... 23 3.2.2 Potential benefits and constraints of expanded regional power trade ......................... 25 4 Evolving electricity system 26 4.1 Electricity system needs ...................................................................................................... 26 4.2 Rationale for Super Grid technology ................................................................................... 27 4.2.1 HVDC for long transmission distance......................................................................... 28 4.2.2 Super Grid – Global approach ..................................................................................... 30 4.3 Rationale for Smart Grid technology .................................................................................. 31 4.3.1 Smart Grid – South Africa approach ........................................................................... 31 5 Concentrating solar power technologies 33 5.1 Technology selection ........................................................................................................... 33 5.2 Parabolic Trough technology .............................................................................................. 35 5.3 Solar Tower technology ...................................................................................................... 36 6 Spatial analysis of potential solar fields 38 6.1 Irradiation potential in Africa .............................................................................................. 38 6.2 Identification of potential solar fields.................................................................................. 40 6.2.1 Evaluation of the suitability of land for solar fields .................................................... 40 6.2.2 Suitability parameters .................................................................................................. 41 6.3 Solar power production sites ............................................................................................... 46 7 Spatial analysis of import corridors 49 7.1 Sub-Saharan Africa energy