Excerpt
Table of Contents
1. Introduction. ... 1
2. Objective. ... 1
3. Current Situation of Rural Electrification. ... 2
3.1. Efforts of Rural Electrification.
... 4
3.2. Energy Demand in Rural Areas. ... 6
3.3. Solar Energy – A Possible Solution?.
... 7
4. PV-Diesel-Hybrid Solutions. ... 10
4.1. Investment Cost. ... 11
4.2. Operating Costs and Payback.
... 12
4.3. Components. ... 13
5. Case Study – Rural Village in Mozambique. ... 15
5.1. Simulation Configuration.
... 15
5.2. Optimization Results. ... 17
5.3. Evaluation of the Hybrid and Diesel-only System..
... 19
6. Conclusion. ... 20
Appendix HOMER Input Summary. ... 21
Bibliography. ... 24
1. Introduction
Currently, about 560 million people in Sub-Saharan Africa (SSA) have no access to electricity and about 625 million people rely on solid biofuels for basic energy needs. The energy access rate varies widely across SSA, in less developed countries and especially in rural areas the access rate is much lower than in developed urban areas. Over 60% of the population in SSA lives in rural areas, often in isolated villages that are inaccessible for the national electricity grid, hence about 89% of rural population have no access to electricity (Legros, 2009). The grid connection is restricted due to cost for a long distance connection which is furthermore associated with transmission losses.
Solutions are needed to expand the access to electricity, especially for basic needs in rural and remote areas. Many rural villages use diesel-fuelled generator sets (diesel gensets) to establish a standalone electric power generation and a local mini-grid. Rising oil prices make diesel gensets, however, an expensive solution to provide electricity. This fact, coupled with high solar irradiation in SSA and dropping solar photovoltaic (PV) prices, create a viable opportunity for a sustainable energy development based on decentralized renewable energy systems. Yet, there Yet, there is a prevailing misconceptions over solar PV, it is typically considered the most expensive technology and therefore unaffordable for poorer rural areas (Lemaire, 2009). This opinion, however, does not consider that in remote areas the running, operation and maintenance cost of diesel gensets exceed the lifetime cost of PV electricity (Muñoz, Narvarte and Lorenzo, 2007). Hence it is arguable that solar PV can economically replace diesel mini-grids or better be a complementary energy source to operate together with the diesel genset as hybrid system (Szabó et. al, 2011).
2. Objective
The main objective of this paper is to analyse if a small scale PV-Diesel hybrid systems can be a feasible solution for rural electrification of a village with a peak demand of 30 kWp in Sub-Saharan Africa? The main question is, if the hybrid system can compete economically and technically with the traditional diesel power generators.
In a first step the current situation of rural electrification in Sub-Sahara Africa will be reviewed and different solutions for current electrification efforts will be analysed. Furthermore recommendations from available case studies and literature on optimal design of hybrid systems will be considered. While in a last step a simulation, by using HOMER simulation software, will compare a diesel generator solution against a PV-diesel hybrid solution regarding initial investment cost, levelized cost of electricity (LCOE), return on investment and payback.
3. Current Situation of Rural Electrification
In industrialized and high-income countries, the grid usually extends to almost the whole population, even to remote users. In developing countries, however, the electricity grid is often limited to areas with the highest population densities (Deichmann et. al, 2011). The electrification rate in SSA is analogous to other developing countries, in the sense that rural areas have either no access to electricity or are dependent on off-grid electricity power systems. Yet the electric power consumption in SSA is the lowest worldwide, as Figure 1 shows.
Figure 1: Electric power consumption (kWh per capita)[1]
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Figure 2: Share of People without Electricity Access (Legros, 2009).
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Especially in remote areas with a low density of demand the lack of access to affordable modern energy is a major issue. Since the electrification level is very low, 75% of total final energy demand in the region is powered by biomass (CORE, 2003). Research has shown that in average 89% of the rural population in SSA has no access to electricity. Figure 2 indicates the low electrification rate, while South Africa is the only country with an electrification rate above 70% (Legros, 2009).
The lack of energy access has negative effects on the socio-economic condition of rural population. Access to electricity enables economic opportunities for income generation and will further reduce people’s time from time-consuming fuel (mostly biomass) collection. Energy access improvement, in particular access to electricity, has huge impacts on education and health. Figure 3 illustrates positive aspects of electricity access, such as more available time allows the rural population to increase their educational activities, and, due to electricity rural households can obtain appropriate lighting for study after the sun has set. Furthermore electricity allows access to information and communication technologies, such as radio and TV which can also be used to educate. As result electricity offers an educational environment for the rural population, it is shown that energy consumption and the education index correlate ( UNDP, 2004; IEA, 2005). Additionally, research has shown that electricity consumption has a significant correlation with GDP (Kanagawa and Nakata, 2008).
Having electricity reduces the hazardous exposure to pollutants and further enables vaccination and medicine storage by refrigerators. In rural areas numerous children are poisoned from paraffin, and whole villages have burned from fires triggered from open flames, research has shown that traditional fuels causes about 2.5 million deaths in rural Africa each year (Howells et. al, 2005).
Figure 3: Links between Energy and other Components of Poverty (Kanagawa and Nakata, 2008)
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3.1. Efforts of Rural Electrification
Energy influences the socio-economic condition of rural areas and access to electricity will significantly improve the quality of life (Kanagawa and Nakata, 2008). The typical approach to connect larger rural areas to electricity is to extend the national or regional grid. The electrification process in SSA has mostly relied on grid extension; however due to the related the high cost, the consequence is that many isolated rural communities stay without access to electricity. The reason for that is that grid extension is only feasible for a large consumer base which resides close to main urban areas. Only a large number of consumers can amortize high fixed cost of a grid extension, the incremental cost of electricity supply increases rapidly as the grid is extended to rural communities whose population is smaller (Deichmann et. al, 2011). In 2011 Szabó et. al gathered data and compiled a map of Africa, figure 4, indicating the existing electricity grid and respective coloured distances to the closest grid connection. Comparing the electrification rate, figure 2, and the distance from the grid, figure 4, shows a relating pattern. The further away from the main transmission lines the least electrified the area is (Szabó et. al, 2011).
Figure 4: Existing Electricity Grid in Africa (Szabó et. al, 2011)
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If grid connection is economically not feasible, the traditional electrification solution is usually decentralized electrification with small diesel-power generator sets. Compared to a grid connection they present a reasonable upfront capital cost per kW installed and provide an economically reasonable solution which can be scaled to consumer needs.
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[1] HIC: High-income countries; EAP: East Asia and Pacific; ECA: Eastern Europe and Central Asia; MNA: Middle East and North Africa: SAS: South Asia; SSA: Sub-Saharan Africa; and RSA: Republic of South Africa.