Distributed power generation versus grid extension: an assessment of solar photovoltaics for rural electrification in Northern Ghana

Abstract

The competitiveness of distributed solar photovoltaic (PV) power generation for rural electrification in northern Ghana is assessed and compared with the conventional option of extending the national grid and increasing the capacity for centralised power generation. A model is constructed to calculate the life-cycle cost (LCC) of the two options and to test the sensitivity of different parameters. All calculations are based on information from the GEF/UNDP pilot region in the East Mamprusi District. In addition to the economic aspect, issues of quality and environmental effects are discussed. The LCC of distributed PV is lower than that of a grid extension for an electricity demand corresponding to solar home systems of 140 W p or smaller. Thus, distributed PV is cost competitive for purposes of lighting, entertainment, information and basic public facilities, such as schools and hospitals. The LCC for the option of grid extension with central power generation is dominated by the cost of low-voltage micro-grids within the communities. Important factors are the density of households and the penetration (fraction of households electrified), as they affect the line length per connected household. The relatively low cost of regional mediumvoltage grids makes the geographical location of each community less important than expected. Battery replacement every fifth year makes up the major part of the LCC of solar home systems and is also responsible for the large energy input in the production of the systems. This could limit both future cost reductions of distributed PV and its potential to mitigate greenhouse gas emissions.

Historical trends in global energy policy and renewable power system issues in Sub-Saharan Africa: The case of solar PV

“…Electricity supply of these remote areas is currently almost non-existent, while urban electrification rate remains really low in the region, at 59.2 %, against more than 95 % in the other developing regions (Table 4). Moreover, not only many Sub-Saharan countries have faced recurrent power crisis over the last years, pointing out the persistent decline of their centralized networks [64] and the lack of reliable power infrastructures [65], but extending a network also requires proper load factors, and so enough gathering of population, to be economically viable [63,66,67]. As a result, these countries are likely more concerned at the present time with improving current grids and power infrastructures than about expanding it so as to reach small, remote and scattered rural areas, which appear on top of that economically less relevant than urban areas [13].…”

“…Especially, in addition to this statement, the very used lead-acid batteries already present short nominal lifetimes combined with intolerance to extreme temperatures [124]. This is a cause for concern as it makes the batteries still standing for the major contribution to the life-cycle investment of a stand-alone PV system [12,18,66]; their multiple replacement along the overall system lifetime reduces its economic relevance.…”

Comparison of various approaches to design wind‐PV rural electrification projects in remote areas of developing countries

“…To do so, the simulated annealing algorithm is used to minimize costs in two phases: first the low voltage network is conceived, identifying the consumption points to be electrified through the microgrid or individually; and then the medium voltage network is designed, determining the location for transformers and the generation system. Applications of ViPOR for the analysis and design of electrification projects in remote areas can be found in Ghana (Nässen, Evertsson, & Andresson, ), India (Kumar & Banerjee, ; Rout & Parida, ), and Peru (Ranaboldo et al, ). Figure shows an example of solution obtained for a fictitious community using ViPOR.…”

Optimización de recursos energéticos en zonas aisladas mediante estrategias de suministro y consumo

“…Para aclarar mejor la idea, se puede poner como ejemplo, los sistemas solares aislados para viviendas (acrónimo en inglés SHS), una solución común en países en vía de desarrollo [143,144,145], que consiste básicamente en sistemas fotovoltaicos de algunos cientos de kilowatts instalados en una vivienda y acompañados de unas baterías para acumulación. Se podría decir que se cuenta con sistemas de generación distribuidos, mas no con una microred.…”

“…Un concepto que se ha planteado en estudios orientados a evaluar opciones de suministro eléctrico en zonas rurales [12], válido para comparaciones entre generación distribuida y extensión de red, es el denominado "penetración", y hace referencia al porcentaje de usuarios existentes en una zona que se conecten a la red, así, si en una determinada zona rural, todas las viviendas existentes se conectan a la solución de electrificación, se podrá hablar de una penetración de 100%; algunos autores suelen expresarla como fracción de viviendas incluidas en el plan de electrificación sobre el total de viviendas de la zona y lo representan con el símbolo . Mientras una más baja penetración da una distribución más dispersa de puntos de carga, la longitud de la línea por hogar conectado incrementa, por consiguiente el costo de vida de la solución (siglas en inglés LCC), que consiste en el valor presente neto de todos los costos que atraviesan la vida útil de una inversión, se ve afectado por el porcentaje de penetración.…”