PhD research about quality and reliability in large photovoltaic rural electrification programmes

1. UNIVERSIDAD POLITÉCNICA DE MADRID
ESCUELA TÉCNICA SUPERIOR DE INGENIERÍA Y
SISTEMAS DE TELECOMUNICACIÓN
CHARACTERISATION OF THE OPERATION &
MAINTENANCE PHASE IN PV RURAL
ELECTRIFICATION PROGRAMMES
THESIS
AUTHOR: LUIS MIGUEL CARRASCO MORENO
DIRECTOR: LUIS NARVARTE FERNÁNDEZ
MADRID, JULY 2015

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TRIBUNAL NOMBRADO PARA JUZGAR LA TESIS DOCTORAL
PRESIDENTE
Eduardo Lorenzo Pigueiras
Catedrático en la Universidad Politécnica de Madrid
VOCALES Beatriz Cancino Madariaga
Profesora en la Universidad Técnica Federico Santa María
(Chile)
Ramón Eyras Daguerre
Profesor en la Universidad Nacional de San Martín
(Argentina)
Jorge Martínez Crespo
Profesor Titular en la Universidad Carlos III de Madrid
SECRETARIO César Sanz Álvaro
Director de la E.T.S. de Ingeniería y Sistemas de
Telecomunicación en la Universidad Politécnica de Madrid
SUPLENTES Jorge Aguilera Tejero
Profesor Titular en la Universidad de Jaén
Luis Marroyo Palomo
Profesor Titular en la Universidad Pública de Navarra
Este tribunal acuerda otorgar la calificación de:
Madrid, 21 de julio de 2015

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v
Dedicado a mis padres,
mi hermana,
mi abuela,
a toda mi familia,
mis amigos
y cómo no, a Adelita.

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ACKNOWLEDGEMENTS
"[...] el olmo ya seco de la ermita
debe su único verdor a la hiedra que le abraza,
pero ella a su vez sólo gracias al viejo tronco
logra crecer hacia el sol."
José Luis Sampedro
Escribió Galdós que la experiencia es una llama que no alumbra sino quemando. Creo que en
mi vida me he chamuscado varias veces, pero no lo he hecho solo y por eso tengo que agradecer a
muchas personas todo lo que de ellas he aprendido trabajando codo con codo hasta llegar aquí,
empezando por Luis Narvarte, mi tutor y director de tesis, alma mater de este trabajo, excelente
persona y amigo, quien me animó a emprenderme en esto de investigar y quien siempre ha estado
disponible para escuchar, pensar y resolver. A Eduardo Lorenzo, por su experta mirada desde lo alto
que tanto ha servido para enderezar mis torcidos renglones. A Ana Peral, que con su trabajo fin de
carrera encendió la mecha de esta tesis. A Teresa, Begoña y Javier de la Universidad Complutense de
Madrid, por su interés en nuestro trabajo y todo lo que nos han aportado. A Michael Conlon,
responsable de la agradable estancia académica en el Dublin Institute of Technology en 2013. A mis
compañer@s del grupo de sistemas fotovoltaicos del IES, que forman entre tod@s el más cordial
ambiente de camaradería de trabajo que he conocido. A tod@s mis colegas de la extinta Isofoton en
España y Marruecos con los que trabajé y aprendí mucho, más allá de la fotovoltaica. Y a much@s
más, que aunque no mencionados, fueron fuente de iluminación.
Agradezco a Isofoton Maroc s.a.r.l. por su colaboración al poner los enormes cimientos en los
que se ha basado el trabajo experimental de esta tesis y a la Universidad Politécnica de Madrid por su
ayuda a financiar parte de los estudios de campo llevados a cabo con el proyecto '35_FOTOVOLT' de
la XI Convocatoria de Acciones de Cooperación Universitaria para el Desarrollo.

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ABSTRACT
With 1,300 million people worldwide deprived of access to electricity (mostly in rural environments),
photovoltaic solar energy has proven to be a cost‐effective solution and the only hope for electrifying
the most remote inhabitants of the planet, where conventional electric grids do not reach because
they are unaffordable. Almost all countries in the world have had some kind of rural photovoltaic
electrification programme during the past 40 years, mainly the poorer countries, where through
different organizational models, millions of solar home systems (small photovoltaic systems for
domestic use) have been installed. During this long period, many barriers have been overcome, such
as quality enhancement, cost reduction, the optimization of designing and sizing, financial
availability, etc. Thanks to this, decentralized rural electrification has recently experienced a change
of scale characterized by new programmes with thousands of solar home systems and long
maintenance periods. Many of these large programmes are being developed with limited success, as
they have generally been based on assumptions that do not correspond to reality, compromising the
economic return that allows long term activity. In this scenario a new challenge emerges, which
approaches the sustainability of large programmes. It is argued that the main cause of unprofitability
is the unexpected high cost of the operation and maintenance of the solar systems. In fact, the lack
of a paradigm in decentralized rural services has led to many private companies to carry out
decentralized electrification programmes blindly. Issues such as the operation and maintenance cost
structure or the reliability of the solar home system components have still not been characterized.
This situation does not allow optimized maintenance structure to be designed to assure the
sustainability and profitability of the operation and maintenance service.
This PhD thesis aims to respond to these needs. Several studies have been carried out based on a real
and large photovoltaic rural electrification programme carried out in Morocco with more than 13,000
solar home systems. An in‐depth reliability assessment has been made from a 5‐year maintenance
database with more than 80,000 maintenance inputs. The results have allowed us to establish the
real reliability functions, the failure rate and the main time to failure of the main components of the
system, reporting these findings for the first time in the field of rural electrification.
Both in‐field experiments on the capacity degradation of batteries and power degradation of
photovoltaic modules have been carried out. During the experiments both samples of batteries and
modules were operating under real conditions integrated into the solar home systems of the
Moroccan programme. In the case of the batteries, the results have enabled us to obtain a proposal
of definition of death of batteries in rural electrification.
A cost assessment of the Moroccan experience based on a 5‐year accounting database has been
carried out to characterize the cost structure of the programme. The results have allowed the major
costs of the photovoltaic electrification to be defined. The overall cost ratio per installed system has
been calculated together with the necessary fees that users would have to pay to make the
operation and maintenance affordable.
Finally, a mathematical optimization model has been proposed to design maintenance structures
based on the previous study results. The tool has been applied to the Moroccan programme with the
aim of validating the model.

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ACRONYMS
AECID: Agencia Españolda de Cooperación para el Desarrollo
AEG: Allgemeine Elektrizitäts Gesellschaft
CC: Charge Controller
CFL: Compact Fluorescent Lamp
CM: Corrective Maintenance
DIn: UK Department of Industry
DOD: Depth Of Discharge
EC: European Communities
ECU: European Currency Unit
EDP: Energy Demonstration Programme
EEC: European Economic Community
ESCO: Energy Service Company
EVA: Ethylene‐Vinyl‐Acetate
GEF: Global Environmental Facility
HW: Hardware
IEA: International Energy Agency
IEC: International Electrotechnical Commission
IES‐UPM: Instituto de Energía Solar ‐ Universidad Politécnica de Madrid
LC: Low power Consumption light lamps
LED: Light‐Emitting Diode
LEDC: Less Economically Developed Countries
MAD: ISO code for the Moroccan currency (dirham)
MDG: Millennium Development Goals
MNRE: Ministry of New and Renewable Energy of India
MPPT: Maximum Power Point Tracker
MTTF: Mean Time To Failure
NGO: Non‐Governmental‐Organizations
O&M: Operation and Maintenance
OEI: Organización de Estados Iberoamericanos
ONEE: Office National de l'Electricité et l'Eau (Morocco)
OW: Orgware
pdf: probability density distribution
PERG: Programme d'Electrification Rurale Globale (Morocco)

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PLANER: Plan Nacional de Electrificación Rural (Spain)
PM: Preventive Maintenance
PPER: Programme Pilote d'Electrification Rurale (Morocco)
ppp: public‐private‐partnership
PV: Photovoltaic
PVPS‐IEA: Photovoltaic Power Systems Programme ‐ IEA
PVRE: Photovoltaic Rural Electrification
PWM: Pulse‐Width Modulation (charge controller)
REA: Rural Electrification Administration
REDP: Renewable Energy Development Project
SE4ALL: Sustainable Energy for All
SGA: Société Générale Agricole
SHS: Solar Home Systems
SLI: Start‐Lighting‐Ignition (Battery)
SOC: State Of Charge
Solar‐PERG: Photovoltaic PERG programme
Solar‐PERGISO: Solar‐PERG carried out by the private company ISOFOTON
SW: Software
UN: United Nations
UNDP: United Nations Development Programme
USAID: United States Agency for International Development
UTSfSHS: Universal Technical Standard for Solar Home Systems
VAT: Value Added Tax
VRLA: Valve‐Regulated Lead‐Acid (Battery)
WB: World Bank
Wp: Watt peak

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SUMMARY
1 INTRODUCTION ......................................................................................................... 3
1.1 THE GLOBAL ACCESS TO ELECTRICITY ................................................................................... 4
1.2 THE ORIGINS OF RURAL ELECTRIFICATION .......................................................................... 11
1.3 REVIEW OF THE DEVELOPMENT OF THE PHOTOVOLTAIC RURAL ELECTRIFICATION .......... 18
1.4 OBJECTIVES OF THE THESIS ................................................................................................. 36
1.5 METHODOLOGY OF THE WORK ........................................................................................... 36
1.6 THESIS STRUCTURE ............................................................................................................. 36
2 THE MOROCCAN PV RURAL ELECTRIFICATION PROGRAMME .................................. 41
2.1 INTRODUCTION ................................................................................................................... 41
2.2 THE PERG PROGRAMME ..................................................................................................... 41
2.3 THE SOLAR‐PERG ORIGIN, DEVELOPMENT AND FEATURES ................................................ 43
2.4 THE ISOFOTON‐PERG PROGRAMME ................................................................................... 46
2.5 SOME COMMENTS ABOUT THE SOLAR PERG DEVELOPMENT ............................................ 53
2.6 THE ISOFOTON‐PERG DATABASE ........................................................................................ 53
3 RELIABILITY ASSESSMENT OF SHS COMPONENTS .................................................... 59
3.1 INTRODUCTION ................................................................................................................... 59
3.2 RELIABILITY ANALYSIS ......................................................................................................... 59
3.3 ANALYSIS OF THE RESULTS .................................................................................................. 65
3.4 APPLICATION EXAMPLE ...................................................................................................... 70
3.5 CONCLUSIONS ..................................................................................................................... 71
4 IN‐THE‐FIELD ASSESSMENT OF BATTERIES AND PV MODULE RELIABILITY IN THE PERG
PROGRAMME ................................................................................................................. 75
4.1 INTRODUCTION ................................................................................................................... 75
4.2 IN‐FIELD BATTERY TESTING ................................................................................................. 76
4.3 IN‐THE‐FIELD PV‐MODULE TESTING .................................................................................... 86
4.4 CONCLUSIONS ..................................................................................................................... 89
5 CHARACTERIZATION OF THE OPERATIONAL & MAINTENANCE COSTS ...................... 93
5.1 INTRODUCTION ................................................................................................................... 93
5.2 COST ANALYSIS .................................................................................................................... 93
5.3 SENSITIVITY ANALYSIS ......................................................................................................... 99
5.4 INFLUENCE OF THE SHS SPATIAL DENSITY ......................................................................... 101
5.5 APPLICATION EXAMPLE .................................................................................................... 102
5.6 CONCLUSIONS ................................................................................................................... 104
6 DESIGN OF DECENTRALIZED MAINTENANCE STRUCTURES IN PHOTOVOLTAIC RURAL
ELECTRIFICATION ...........................................................................................................109

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6.1 INTRODUCTION ................................................................................................................. 109
6.2 BASELINE DATA ................................................................................................................. 110
6.3 METHODOLOGY ................................................................................................................ 110
6.4 MODEL APPLICATION ........................................................................................................ 118
6.5 CONCLUSIONS ................................................................................................................... 122
7 CONCLUSIONS AND FUTURE RESEARCH ..................................................................125
7.1 CONCLUSIONS ................................................................................................................... 125
7.2 FUTURE LINES OF RESEARCH ............................................................................................. 128
PUBLICATIONS GENERATED DURING THIS PHD ..............................................................131
BIBLIOGRAPHY ..............................................................................................................135

15.
CHAPTER 1
INTRODUCTION

17. Chapter 1: Introduction
3
1 INTRODUCTION
Beyond the reasons that justify the right of every human to have access to modern sources of
energy, the importance of electricity as energy vector, from the first application of the late
nineteenth century to today, lies in the fact that it is easy to transport and simple to operate.
Nowadays there are still 1,300 million people deprived of electricity, 85% of them in remote rural
areas where electrification encounters problems such as high economic investments, low
profitability or difficulty of operation, among others. In these cases, decentralised electrification by
means of solar home systems (SHS) has aimed to be a technical and cost‐effective solution for over
40 years in many countries of the world. Currently, large‐scale electrification programmes with
thousand of SHSs are established in remote and impoverished regions, whose results, in terms of
sustainability, are in doubt. These attempts at electrification are frequently based on assumptions,
such as electricity consumption, device reliability, operating costs, rural spending habits, etc, which
bear little resemblance to reality. The consequences are the long term economic instability of the
programmes, the failure of private operators and the abandonment of SHSs, which has happened in
many initiatives developed in recent decades.
This work presents a study based on a real and large photovoltaic rural electrification (PVRE)
programme, taking advantage of the excellent opportunity that the author took advantage of
whilst, for five years, being part of the management team of the company that operated that
programme, having full access to the detailed maintenance data, failure of the SHS components,
unit costs, management structure, activity organization, etc, during that period. The study provides
the chance, for the first time, to contrast the real data of decentralised electrification with the
classic assumptions, by means of the SHS's reliability statistic research, the characterization of the
actual costs in the operation and maintenance (O&M) phase and the study of the application of the
results in the formulation of PVRE programmes.
This chapter introduces the detailed historical evolution of rural electrification, in general and the
photovoltaic rural technology, in particular, which nowadays has culminated in the implementation
of large PVRE programmes. First, it focuses on the problem of access to electricity and discusses the
difficulties that it faces. Then, a review of the rural electrification origins throughout the 20th
century is presented to show that barriers and solutions at the beginning of rural electrification are
similar to the current challenges. Finally, an historical review of photovoltaic rural technology
evolution shows that the three dimensions that integrate it (hardware, software and orgware) have
unequally evolved to the present day, which gives rise to a still non‐mature technology.
The chapter concludes with the main objectives of the thesis, a brief explanation of the
methodology of the work and the description of the document structure.

18. Chapter 1: Introduction
4
1.1 THE GLOBAL ACCESS TO ELECTRICITY
1.1.1 Current status: 1,300 million people without electricity
Nowadays, the lack of access to electricity affects to 1,300 million people worldwide, 20% of the
world’s population. This figure, published by the International Energy Agency (IEA) in 2012 ‐ World
Energy Outlook Report, [1] ‐ gives us an overall idea of a problem to be solved globally, similar to
other issues such as hunger, access to clean water, sanitation, etc. According to the IEA, this figure
has decreased since 1990, from 2,000 million people, to 1,300 million in 2010. Not only that, in just
in 8 years (2002 ‐ 2010), it has been reduced from 1,623 million to 1,267, a gap of new 356 million
people with access to electricity (more than the population of the United States of America).
However, these figures are just estimations (as recognized by the IEA), since the lack of access to
electricity is something specific to the marginal and rural areas of the less economically developed
countries (LEDC), where the inaccuracy of the population census, also affected by the double and
opposing effect of population growth and migration to urban areas, precludes any accurate
estimations [2].
1.1.2 The IEA expects that universal access to electricity will be achieved in part with
Solar Home Systems
From the perspective of reducing the world population without access to electricity, in 2010 the
United Nations (UN) launched the Sustainable Energy for All (SE4ALL) initiative to "achieve universal
energy access, improve energy efficiency, and increase the use of renewable energy" [3] (It must be
remembered that the UN for many years did not include action on energy poverty in the
Millennium Development Goals).
The 2011 World Energy Outlook report [4] published by the IEA estimated the necessary
investment for electricity universal access, between 2010 and 2030, at US$ 640 billion (this
requirement is small when compared to overall energy‐related infrastructure investment,
equivalent to around 3% of the total). The report suggests that 70% of the required infrastructure
would consist of off‐grid systems: mini‐grids (65% of this share) and stand‐alone off‐grid solutions
(the remaining 35%), that is, solar home systems (SHS), small hydro systems, and others (wind and
biogas). We estimate that nowadays, the SHSs represent 95% of the stand alone system installed
worldwide. So, the IEA foresees an investment of around US$ 150 billion for SHSs to reach universal
access to electricity before 2030. If photovoltaic (PV) systems were sized to meet housing
consumption between 250 and 500 kWh/year [5], the required SHS power would be 180 ‐ 365
watts peak (Wp). Taking into account a unit cost for the installed SHSs of between US$ 6 ‐ 8 /Wp1
, it
would correspond to installing more than 50 million SHSs, giving access to electricity to 250 million
people.
1.1.3 Why the lack of electricity is a problem
Access to electricity is not considered a universal fundamental right of people [6]. However, there is
a unanimous opinion that electrical supply is a priority factor which is urgent to resolve. Therefore,
in the last decade there have been numerous initiatives to address the problem, such us the Global
1
It includes equipment, transportation, installation of the SHSs and 10% of overhead expenses.

19. Chapter 1: Introduction
5
Environmental Facility ‐ GEF [7], the Millennium Development Goals [8] and the Sustainable Energy
for ALL (SE4ALL) from the UN [3], "Luz para Todos" in Brazil [9], Power for all in India [10] or "Luces
para aprender" from the Organization of Ibero‐American States (OEI) [11], among others.
Apart from the extended consideration in Western culture that human enrichment as a society, in
economic, social, political and cultural aspects, is necessarily linked to infrastructure development
[12, 13], perhaps, the best arguments that justify the need for access to electricity are included in
the Millennium Development Goals (MDG). In this resolution, adopted by the UN in 2000, although
there are no specific MDGs relating to energy, it has been recognized that MDGs cannot be met
without affordable, accessible and reliable energy services (Table 1):
Table 1: Importance of electrical access for achieving the MDGs
Goal 1:
Eradicate extreme
poverty
Access to modern electricity increases household incomes through
economic development and reduces the burden of time‐consuming
domestic labour. Electricity supply enables poor households to engage
in activities that generate income by providing lighting that extends the
working day and by powering machines that increase output.
Goals 2 and 3:
Universal primary
education and promote
gender equality and
empowerment of
women
For poor people everywhere, access to electricity frees time for
education; time that would otherwise be spent collecting traditional
fuels, fetching water, processing food or in other physical work. Access
to electricity contributes to the empowerment of women. Increasing
access to energy brings major benefits for women and girls; in health,
education, and productive activities.
Goals 4, 5 and 6:
Reduce child and
maternal mortality and
reduce diseases
Electricity helps improve health by powering equipment for pumping
and treating water; it enable health clinics to refrigerate vaccines,
operate and sterilize medical equipment, and provide lighting. It allows
the use of modern tools of mass communication needed to fight the
spread of HIV/AIDS and other preventable diseases. Access to electricity
helps attract and retain health and social workers in rural areas by
improving living conditions.
Goal 7:
Ensure environmental
sustainability
Energy use and production affect in local, regional and global
environments. The environmental damage and its harmful effects can
be reduced by increasing energy efficiency, introducing modern
technologies for energy production and using renewable energy.
Goal 8:
Develop a global
partnership for
development
The World Summit for Sustainable Development called for partnerships
between public entities, development agencies, civil society and the
private sector to support sustainable development, including the
delivery of affordable, reliable and environmentally sustainable energy
services.
However, these arguments, usually very common in the literature, should be treated with caution,
since, very often, the availability of electricity does not directly involve any development [14, 15].
An example that refutes this attribution is the Moroccan Global Rural Electrification Programme

20. Chapter 1: Introduction
6
(PERG in French acronym), which will be widely discussed in this work. This electrification
programme focused on providing electricity mainly to housing and not to farmlands, which are the
places where electrification could have some impact on the development of the local economy. The
case of Tizi n'Ait Amer, a small village of just 700 inhabitants in the south of Morocco, is illustrative.
It got access to electricity 10 years ago and every dwelling is connected to the grid. However, no
new economical activities have been developed since the electrification of the village. The only
hope of carrying out new activities has been the extension of agricultural lands, which has recently
become possible thanks to the installation of a photovoltaic water pumping system to irrigate the
new crops, as the wells are 400 meters from the village and the grid does not reach it2
. This
example shows that giving access to dwellings is not enough for economical development. Rural
electrification must be more ambitious if new economical activities are to be implemented.
From a different point of view, most modern societies are economically based on the so‐called
"consumer economy", thus it is not surprising that private corporations, financial institutions and
public administrations are interested in the extension of the economy to the rural population,
focusing in the fact that access to electricity contributes to the acceleration of that process
(consider, however, the existing criticisms of the dominant current model of economic growth, but
this subject is far from the arguments addressed in this thesis).
Beyond corporate or market interests, the extension of the access to electricity is currently in the
hands of the people themselves, that even knowing about the electricity, they still live without it
and therefore they demand it. To a greater or lesser extent, modern standards of living have spread
to the most remote areas of the planet, and so electric lighting, television and mobile phones are
currently perceived as basic needs in the rural areas of impoverished countries. The introduction of
these everyday uses requires the availability of electricity. It can be said that after more than a
century of electrification, the current demand for electricity is global.
1.1.4 Blocking factors
Despite the efforts made to enhance the conditions for people in rural environments, the fact is
that the access to electricity rates are still very low in some regions of the planet (Sub‐Saharan
Africa and South Asia constitutes 95% of the world population without access to electricity).
The evolution of the rate of access to electricity is affected by several factors:
a) Positive factors that increase the electrification rate:
‐ Migration from rural to urban areas
‐ Rural electrification
‐ Maturity, quality and cost reduction of new technologies
b) Negative factors that reduce the electrification rate:
‐ The high birth rates in rural areas of impoverished countries
‐ The increased costs of conventional technologies
2
Own sources. The PV pump installed in Tizi n'Ait Amer belongs to a project financed by the Spanish
International Cooperation (AECID) and the Universidad Politécnica de Madrid (UPM)

21. Chapter 1: Introduction
7
These factors, which could be quantified, depend on other more unpredictable and difficult
weighting factors, such as political will, armed conflict, famine, natural disasters, etc.
Considering the last 3 decades (1980 ‐ 2010), an analysis of the factors involved in global access to
electricity could be carried out just by assigning an indicator to each factor (Table 2).
Table 2: Factors that quantitatively affect the evolution of global access to electricity
Factor Indicator 1980 2010
Migration from rural to
urban areas
Rural population (nº
of people living in
rural environment)
2,675,822,000
(61% of the
population)
3,320,679,000
(48% of the
population)
Birth
World population (nº
of people)
4,413,536,000
6,861,918,000
(increased by
55%)
Rural electrification
programmes
People without access
to electricity
2,000,000,000
(45%)
1,300,000,000
(20%)
Maturity and reduced
costs of new technologies
Photovoltaic systems
costs ($/Wp of the
photovoltaic module)
$12
$0.8 (93%
reduction)
Increased costs of
conventional
technologies
Crude oil prices (US$/
barrel) [16]
Jan. 1970 (Before
1970s oil crisis)
US$ 21.00
July 2010
US$ 82.25
1.1.4.1 The increase in the rural population
On the one hand, in spite of the strong migration impact towards the cities (in 2007 there was the
historical phenomenon that, for the first time, the world population changed from mainly rural to
urban), the high global birth rate has meant that in 3 decades the world’s rural population has
increased by 25% (more than 600 million people).
On the other hand, although the rural electrification programmes have contributed to increasing
the rate of access to electricity, it is not known precisely what was this rate in the 1980s, but it can
be estimated that the overall number of people without access to electricity remained constant
during that decade at 2,000 million, which means 45% of the population [17]. If the figure was
reduced to 1,300 million in 2010, it means that the rate of access to electricity is still higher than
the growth rate of the rural population, which is a very encouraging fact (see Figure 1) on the
evolution of the global access to electricity, especially in Asia, where the ratio of people without
power is declining rapidly (China gave access to electricity to more than 700 million people
between 1980 and 2000 [18], and the country's electrification rate currently exceeds 99% [5]). Sub‐
Saharan Africa, however, remains as the only region of the world where the number of people
without access to electricity is increasing.

22. Chapter 1: Introduction
8
Figure 1: Global evolution of population, rural population and lack of access to electricity until 2013. World
Bank [19]
1.1.4.2 Conventional electrification is becoming more expensive
The current high costs of conventional rural electrification systems are affected, among other
factors, by the increased prices of fossil fuels. For example, in US, the cost of electricity for
residential use has doubled in three decades. In Europe, between 2002 and 2013, the cost of
electricity for households has gone up by 61%.3
Among the less electrified regions of the world, Sub‐Saharan Africa has the most expensive
electricity tariff in the world, on average between US$ 0.13 ‐ $0.14/kWh (in comparison, electricity
tariffs in Latin America, Eastern Europe and East Asia are around US$ 0.08/kWh.) [5], which lie well
below the true cost of production, which on average is US$ 0.18/kWh, preventing any return in
capital, thus threatening the long‐term sustainability of the utilities in the region [20].
If, in addition, we consider the investment needed to provide access to electricity to rural
communities, it should be noted that the infrastructure costs for conventional electrification
(extensions of electricity grids mainly through the medium and low voltage lines) has increased
considerably. These lines use raw materials such as iron and copper, whose market prices have
increased 2 and 5 fold respectively from 1980 to now [21]. The average cost of a medium voltage
line is around €6,000/km (case of 11 kV; cost of medium voltage transformers or operation and
maintenance not included [22, 23, 24, 25]) and its impact on the energy costs can be estimated at
€2.5c/kWh/km [26].
At the same time, during the last 40 years, the silicon flat‐plate photovoltaic industry (that
represents more than 90% of the global photovoltaic market) has reduced its costs by 93%, so in
the sunniest countries, such as the Mediterranean area, or most of the African continent, it is now
3
Note, however, that the integration of renewable energy sources into the European energy mix has also
affected the increase in tariffs.
‐
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
1950 1960 1970 1980 1990 2000 2010 2020
Million of people
World
Rural World
Without electricity access
7,125
3,336
1,285

23. Chapter 1: Introduction
9
feasible to produce solar electricity at a cost around4
€8c/kWh , which could lead to the possibility
of a medium term change of paradigm.
On other matters, from 1980 to 2010, electrical power consumption in the world has increased by
more than 150%, at a rate nearly 5% per year (Figure 2). However, the human population has
grown at a rate of 1.8% per year, which indicates that electricity consumption per capita has
increased almost 3 fold in 30 years. Although the development of the industry carries a lot of
weight in these results, it is also obvious that home electricity consumption is growing. This fact
suggests that providing access to electricity leads not only to an increase in the power required to
meet the new connections, but also that this power needs to be gradually increased according to
trends in household consumption.
Figure 2: Evolution of the World’s electricity capacity, generation, consumption and losses [27]
Within the great figures of the world electricity generation, it is worth mentioning the importance
of the distribution energy losses (see Figure 2), which represent 8 ‐ 9% of the electricity generated
every year worldwide. This means annual losses of 1,800∙106
MWh, enough to supply electricity to
a country of more than 300 million inhabitants with the European standard consumption of
electricity (5.4 MWh/person/year [28]). Not only that. Taking into account the minimum electrical
consumption to guarantee basic life conditions (1 MWh/person/year [29]), the figure would
become 1,800 million people; and considering the average consumption per capita in Africa (0.5
MWh/person/year), this figure would rise to 3,600 million people, almost 3 times the world’s
population without access to electricity.
4
It concerns large photovoltaic (PV) power plants. Taking into account a power degradation rate of 1%/year
for PV modules and a lifetime of 25 years, 1 kWp PV power could produce around 44,500 kWh for 25 years
(solar radiation = 5.5 kWh/m2
/day). At current PV power plant investment prices (€1.5 /Wp), a performance
ratio PR = 0.75 and O&M costs corresponding to 3% yearly of the investment cost, the produced solar energy
cost would be €7.8c/kWh.
0
1,000
2,000
3,000
4,000
5,000
6,000
0
5,000
10,000
15,000
20,000
25,000
1975 1980 1985 1990 1995 2000 2005 2010 2015
Total Electricity Net Consumption (Billion Kilowatthours)
Electricity Distribution Losses (Billion Kilowatthours)
Total Electricity Installed Capacity (Million Kilowatts)
109 kWh 106 kW

24. Chapter 1: Introduction
10
1.1.4.3 Political and social factors
In the current global energy scenario, with a declining growth rate of the world’s rural population
and viable alternatives to conventional electrification, we can estimate that technical and
economical aspects are not the only cause impeding access to electricity. The development of rural
electrification also depends on other factors such as political will, social acceptance, subsidies and
agricultural development policies, among others.
It is socially accepted that renewable energies, especially photovoltaic technology, are "expensive"
and have low reliability compared to conventional technologies, so they would require a great deal
of investment for implementation and the power supply could not be guaranteed. But, in 2013
subsidies to conventional energies, such as petroleum, reached US$550 billion all around the world,
4 times higher than the amount dedicated to renewable energies [30]; or, in the same context, as
regards rural electrification, the World Bank (WB) argues that subsidies for grid electrification are
significantly greater than those for off‐grid electrification [31].
As regards rural development in impoverished countries, the lack of structure in the agricultural
sector also contributes to impeding access to electricity, since the agricultural policies require
investments in infrastructures to be made in the agricultural economy and dignify the peasant's
lives. Thus, it is very unlikely that a country without agricultural policies will be able to allow the
rural population to get access to electricity. As will be set out below, rural electrification in almost
all Western countries in the mid‐20st century was developed in parallel with agriculture with the
aim of modernizing the countryside and increasing agricultural production ratios.
Finally, it must be taken into account that rural electrification especially addresses a particular part
of society, the peasants. They have been historically constituted as an independent economy
characterized by the fact that the peasantry has always supported itself. The peasant community is
the most aware class with regard to its economy, which determines the decisions that they take
daily. The difference between a peasant and other society member is that the former knows
perfectly what he obtains from his work: he produces what he needs to live and the rest of the
production can be a surplus value when sold on. On the other hand, a worker from the "standard"
society never knows the real value of the product of his work. Thus, is important to realize that
giving access to electricity to rural people means an incursion from the macro‐economy into the
peasant economy, with all the difficulties involved (resistance to change). For example, rural
inhabitants from countries like Morocco are not familiarized with public services such as electricity,
and it is difficult to admit concepts like the payment of monthly fees or the long term contracts, or
contractual rights and obligations.
To better understand the phenomenon of contrast in the development of rural electrification,
which prevails both in the effort to electrify and the problem of electrification, there is nothing
better than referring back at the origins of rural electrification in the Western countries carried out
during the twentieth century.

25. Chapter 1: Introduction
11
1.2 THE ORIGINS OF RURAL ELECTRIFICATION
1.2.1 The appeal of electricity
1.2.1.1 Start of the marketing of electricity. The 1881 Paris Exposition
Electricity and its applications have fascinated humans since the beginning of the industry over 130
years ago. When today a peasant family without access to electricity in an impoverished country
finally gets access to it, the ability to marvel at the optimum quality of electric lighting in addition to
the possibility of using appliances like TV or mobile phone must be very similar to that experienced
by our ancestors in the late nineteenth century.
It may be argued that the commercial inception of the electrical industry began with the
International Exhibition in Paris in 1881, exclusively dedicated to electricity, that brought together
many of the inventors and industrialists from the emerging sector at the time to exhibit their
creations and show them to the world (Figure 3). It was the closest thing to what we now
understand as an industrial exhibition. It was attended by over 600,000 visitors and had over a
thousand exhibitors (including Thomas A. Edison, Joseph W. Swan, Zénobe T. Gramme, A. Graham
Bell, William Thomson, etc), 19 of whom came from Spain [32].
Figure 3: Overview of the International Exhibition of Electricity, Paris 1881 (appeared in Nature, 1881
second quarter)
Inside the Palais de l'Industrie, which then occupied the place where now stands the Grand Palais
des Champs Elisées, the latter built to host 1900 Universal Exhibition, all kinds of inventions for
electric power generation, transmission and application were exhibited, from a lighthouse, boats
and even an airship driven by electric motors, submarine cables, telegraphy apparatuses,
electrochemical batteries, electric stoves, large magneto‐electric machines, microphones, trams,
etc.

26. Chapter 1: Introduction
12
But surely, there were two applications which caused more excitement: the phone and lighting. On
the latter, the Spanish magazine "La Ilustración Española y Americana" published in reference to
the Paris Exhibition the following [32]:
"On the bottom left, there are all the known generators: steam, gas, or by means of batteries.
Further, a series of powerful gas engines or steam, which set in motion the dynamo‐magneto‐
electric machines of Gramme, Lontin, Siemens and Meritens, which send torrents of electricity
to the lamps of various systems, which shine splendidly inside the Palace with the most
brilliant clarity that human industry has ever produced and with the astonished gaze of man
has ever seen."
Thus, electric lighting was the first application of electricity that amazed humanity and became the
engine of development and expansion, thus making other means of artificial lighting practically
inconceivable.
1.2.1.2 First public supply of electricity in a rural setting: Godalming 1881
Coinciding with the 1881 Exhibition in Paris, and one year before that the famous electric power
plant of Pearl Street in New York (September, 1882) was inaugurated, it took place in September,
1881 in Godalming (England) the first experience in the rural supply of electricity on record, built to
provide street lighting for the town, and replacing the existing gas‐lighting system. In the last
quarter of the nineteenth century, electricity was perceived by society within the realm of the
"scientific". The fact that it was applied in a small town of only 2,000 inhabitants caused a huge
interest around the country. The power generation genius system and the welcome given by not
only the local and surrounding population, but also by the press, because of the good quality of
lighting [33], started the paradigm of what electricity would mean for humanity throughout the
coming century. However, the enormous expectation of the pioneering system and its initial
success had to deal with its technical immaturity and despite the enthusiasm of its promoters, the
private company of electricians Calder & Barnet, eventually abandoned its contract with the Town
of Godalming, which in turn was taken over by Siemens and after numerous problems, causing
continuous and repeated outages, Godalming went back to gas lighting only 2 and a half years after
the start of the new experience. Electricity would come back to Godalming in 1904 and this time
would be forever.
1.2.1.3 The urban development of the electrification
Electrification applied to lighting was really confined to the big cities, whose beginnings were
marked by the fierce competition against gas‐lighting, but the rapid popularity of electricity and its
great reception brought about its rapid expansion.
The first urban experiences of using electricity did not go beyond being mere exhibitions. For
example the lighting of Puerta del Sol in Madrid in 1875, or in 1878, to mark the engagement
between King Alfonso XII and his cousin Maria de las Mercedes (who was only 17 years old. She
would die of typhus just five months later, giving rise to the famous legend of the love between
them and the traditional songs that have survived in popular heritage), or other more extravagant
events, like the first night bullfight with not very good results in 1879, which "La Ilustración
Española y Americana" would outline [32]:
"If the shadows of our grandparents hold bullfight functions in the Otherworld, they should be
very similar, because what we saw was a show of silhouettes."

27. Chapter 1: Introduction
13
In the late nineteenth century, European cities were equipped with a gas lighting service operated
by private companies. The pioneers of electrification were also private companies, and after
electricity superseded gas lighting, many gas companies turned to electricity. Thus emerged a
network of companies that obtained concessions (from municipalities) to illuminate streets or even
whole neighbourhoods. The companies employed steam engines and alternators installed
wherever they could (rented basements, cellars, etc) to power the street lights. Very soon,
theatres, cafes, public buildings, and later dwellings, would also be electrified which led to complex
commercial competition between the numerous electric companies (Figure 4), generating a price
war in order to win customers. Electrical distribution was born, therefore, as a totally private and
decentralized system.
Figure 4: Electricity sales advertisement appeared in an early 20th century newspaper from Barcelona
1.2.1.4 The world's largest industry emerges: the electrical industry
The development of the electricity supply industry was possible thanks to private equity, closely
linked to the European industry. In the case of Spain, the first electric company, also founded in
1881, was the "Sociedad Española de Electricidad", with a company's share capital of 20 million
pesetas, and created by D. Tomás Dalmau, who owned an "optics and physics" shop in Barcelona,
and who had previously introduced the Gramme machine in Spain in 1873, which subsequently
obtained a license for manufacturing.
The "Sociedad Española de Electricidad" installed a multitude of electrical supply equipment for
public and interior lighting in many cities in Spain, especially Barcelona and its surroundings, even
overseas (Cuba and the Philippines) and navy warships. The representative of the company in
Madrid, who was also a partner, the engineer and inventor Artilleryman Colonel Isodoro Cabanyes,
had already equipped his atelier with electricity in 1881 for lighting and motive power. He was
responsible for many of the first electrical project demonstration in Spain. It is worth mentioning
that Cabanyes would work some years later on the use of solar energy for decentralized rural
applications in the field of agricultural irrigation, firstly through a "solar reflector system" (Figure 5)
and afterward with the "solar air engine" [34].
The company was taken over in 1894 by the German company Allgemeine Elektrizitäts Gesellschaft
(AEG) who founded the "Compañía Barcelonesa de Electricidad" in the same year [35, 36, 37, 38,
39].

28. Chapter 1: Introduction
14
Figure 5: Cabanyes's solar reflector. It appeared in 1890 in the magazine La Gaceta Industrial [34]
Electricity generation, initially produced by means of the steam engine, made the leap to
hydroelectricity, which meant a reduction in the costs of production and consequently electricity
tariffs, initiating the development of large electrical distribution networks.
This new situation led to the need to make major investments in the construction of dams and
reservoirs, artificial waterfalls, high voltage distribution lines, etc. However, the enormous
investments necessary could not be covered by the limited national electric companies, nor even
the public administration, so since the very early days, the electricity industry in Spain, which in the
1930s was the most important in terms of investment, exceeding that of the rail and mining
industries, needed the intervention of international investment holdings to meet the costs of the
rapid development of the electricity sector. In the early 1930s all European utilities were already in
the hands of roughly 20 companies, thus shaping what would later become the paradigm of
centralized electrification [36].
1.2.2 The beginnings of rural electrification and its problem of profitability
After the introduction of use of electricity in the cities, the Spanish countryside showed little
interest in the new technology. However, the public administration considered electricity as the
panacea for the 3 major rural problems of the Spanish post‐civil war years [40]: unemployment,
poverty and the consequent rural exodus. However, access to electricity in the countryside had to
face two major obstacles: "the enormous cost of setting up the transmission and distribution of
electricity" and the lack of interest of the rural population towards technological innovation. The
first problem was solved through subsidies and as regards the latter, Luis González Abela in his
book "La Electrificación Rural, Problema Nacional " published in 1942 described the problem in thus
[40]:
"... there is only one way to overcome it, which is a very active advertising through pamphlets,
daily and technical press, radio, cinema and whatever means possible, which will highlight the
transcendental benefits that would result giving access to electricity to our honoured
peasants, because there is no reason for them to be second‐class citizens and because they
did not commit any offense in having born in the countryside ... "

29. Chapter 1: Introduction
15
An example of these transcendental benefits was cited in the Congress of Rural Electrification in
1948, held at the School of Industrial Engineers of Madrid [41], in which the importance of using
radio receivers for the Spanish peasant was mentioned:
"... [the peasant] isolation is broken in this way. He belongs to the great human family. He
can cultivate his Spirit, increase his knowledge, participate in the national life and enjoy the
artistic beauties of music whenever he wants. Not enough can ever be said about the benefits
of radio in the life of an isolated peasant. "
Much less documented than urban electrification, rural electrification was carried out in parallel
with the urban, but with a different approach and significant limitations. On the one hand, the
existence of small waterfalls that were used in the flour mills, saw mills, foundries, etc, were
exploited by means of small generators (dynamos) to provide electricity to small towns. Again, the
origin of the electrification system, like the urban one, was absolutely decentralized. From that
mentioned at the 1948 Congress of Rural Electrification, the following is extracted [41]:
"The typical electric mill that is used in many towns and all of its electrical industry is known;
it is a completely logical solution, which adequately meets the needs of these people. It is
enough to have a small water flow, provided by any ravine that goes to a canal that carries
the water to a small pond. At the foot of it, a turbine with a dynamo and engine is installed,
achieving a power of 5 to 20 CV; the latter serves to supply electricity to several towns. During
the daytime it works as mill, and at night, the dynamo supplies lighting to the town. This is
the reality for a large area of the country, and as long as the Spanish countryside does not
change its habits, what nowadays seems to be difficult, the National power distribution
networks and the rural electrification will be superfluous."
They were small companies including municipalities and agricultural cooperatives which were
commissioned in the early decades to deal with these matters. The technical and productive
limitations of the electrical rural generators, the distribution losses (voltage drops) and the gradual
increase in loads (users added more lighting points, or appliances every year), caused the electric
service to be of very poor quality, with frequent power outages and failures of the generator or
even in the distribution network. From the aforementioned 1948 publication, the following was
cited [41]:
"... the technical solution for creating small local power plants or, at most, at a regional level,
installed in waterfalls that are built ad hoc or even using already existing mill and sawmill
facilities, is usually not effective, unless, even within modesty of the installations, their energy
power far exceeds that required for the loads."
At the time, the notion of critical mass of users that would allow to a company to manage an
electrical network with an economic return was already mentioned [41]:
"... the towns where electrical lighting has not yet arrived, not only will not give profits but
losses, even if the facilities were freely outsourced to the nearest distributor, as the expected
revenue would be 75‐100 pesetas per month on average at current tariffs, because towns
have between 15 and 40 neighbours, most of them with poor access, and therefore the
operation of electrical services is very expensive."
"The solution must be sought permitting the rural distributors to apply an adapted tariff
throughout its region. In this way, while tariffs remain moderate for the entire electricity
rates, the distributors can increase it to get the real rural electrification in the area that they

30. Chapter 1: Introduction
16
manage. So these new rates shall be applied to the rural market in which villages with up to
2,000 subscribers must be included. "
Another singularity of the rural electrification, which directly affects the problem of the
profitability should also be noted: the collection of the user fees. Given that the peasant and his
family spend most of the daylight hours in agricultural activities, it is most likely that collectors,
when they visit their customers will not find anyone at home, so the already high cost of moving
around remote regions is increased as they have to return repeatedly. In this regard, another
extract from the 1948 Congress is shown [41]:
"Collection of receipts.‐ currently, they are charged at home, which is very expensive because
the collector does not always find all the neighbours at home, so he is bound to make several
trips, and very likely he may not be able to complete the collection."
As a result of this historical evidence, it can be argued that some of the problems that rural
electrification had to face in the first half of the twentieth century were based on the lack of
profitability for the utilities, due to the high costs of infrastructure (network extensions), no return
on investment (very low consumption of electricity) and insurmountable operation and
maintenance tasks (remote and dispersed customers and difficulty in managing users' fee
collection). As will be seen below, these problems have remained to date.
1.2.3 Rural electrification to modernize agriculture
In 1932, during the Second Spanish Republic, the Instituto de Ingenieros Civiles (now known as the
Instituto de la Ingeniería de España [42]), organized a series of conferences on rural electrification
dedicated to electrical energy applied to agriculture, where in a somewhat visionary way it
addressed the tilling of the land by means of electric machines, in addition to the "electroculture of
crops" (direct application of electricity to the crops to influence their development). The focus of
the conferences was the French experience, which had already almost 40,000 electrified towns and
used the "electric‐tiller" (Figure 6) for agricultural work in France, its Protectorates and Colonies
[43]:
"... the Gas Lebón Company, in Algeria [...] had decided to give a subsidy of 300,000 Francs to
private farmers and agricultural cooperatives that purchased electric‐tillers of more than 100
H.P."
Figure 6: Electric‐tiller with cable winch, owned by the Société Générale Agricole (SGA). Photo from [43]

31. Chapter 1: Introduction
17
It is known that later, during the second half of the twentieth century, the engine of development
of rural electrification were policies focused on agricultural modernization, carried out in the
European post‐war as a means of activating the European economy.
"... to turn electrification into a profitable activity, it must cover electric‐tilling, harvesting,
threshing and other available operations using electric motors ..." [41]
Thus, the idea was to extend the grids, at the time fed by large hydraulic and thermal power plants,
toward farms with the aim of increasing crop yields through the use of new electrical equipment.
However, the private companies, which had flourished within urban electrification, did not perceive
the same business opportunity in rural electrification that had it had seen in the cities, for the
aforementioned reasons.
1.2.4 Public subsidies for rural electrification
Then government intervention was required through incentives for both the utilities and the rural
users in order to make the rural electrification attractive to them. In most Western countries rural
electrification was achieved through grants and loans provided to the electricity companies to
ensure a return on the investment, and carrying out awareness campaigns addressed to the rural
population to ensure a minimal electric power consumption.
For example, the US created a rural electrification agency (the Rural Electrification Administration ‐
REA) with the aim of funding the utilities that were electrifying the rural areas [44, 45]. In the
1930s, the US administration launched a promotional campaign aimed at encouraging the peasants
to use electricity (at the time they were reluctant to pay for an electric service that never had
needed before) for different domestic appliances and machinery for agriculture and livestock farm
work (Figure 7).
Figure 7: Two of the advertisements that the REA agency used for electrification promotion in the 1930s to
increase awareness among the rural population on the benefits of electricity.

32. Chapter 1: Introduction
18
Thanks to this campaign, an electrification rate close to 100% in US was attempted in few decades,
which contributed to popularizing the use of domestic appliances, such as television, oven, iron,
bread machine, vacuum cleaner, etc, which would later be exported all over the world. It had the
same impact on agriculture, and the consequent employment of sophisticated electrical power
tools.
1.2.4.1 Public subsidies: The Spanish PLANER
In 1974, in Spain, more than 900,000 rural people still lacked access to the public service electricity
lines (over 6% of rural population). Giving access to electricity to that remote population meant a
huge investment and negative profitability because of the wide dispersion and low purchasing
power of the population. The 1973 National Electrical census indicated that while the density of
subscribers in urban areas was 116.68 per km2
, in rural areas it was 11.42 per km2
. Moreover, while
the mean urban consumption was 6,244 kWh/year (per dwelling), the rural rate was 885 kWh/year,
i.e. the rural household consumption was 7 times lower than the urban one and the dispersion of
the dwellings was 10 times higher, what meant that the rural electrification costs were 70 times
higher than the urban costs [46].
Although most of the electricity companies in Spain were private, the Spanish government
launched the rural electrification plan, PLANER in Spanish acronym, [47] with the aim of providing
access to the non‐electrified rural population, upgrading rural power grids and contributing to the
increase in agricultural and rural electricity consumption. The programme was carried out between
1976 and 1989. Just from 1982 to 1989 [48], the amount of these subsidies reached 32 billion
pesetas (more than €700 million at current rates [49]).
In parallel to the modernization and extension of the conventional power grids,the first experiences
in decentralized electrification was carried out in the 1980s by means of renewable energies,
promoted by the National Institute for Reform and Development (IRYDA in Spanish acronym) within
the PLANER programme. Around 3 million ECU (European Currency Unit) were dedicated between
1982 and 1985 (€4.6 million at current rates, applying inflation rate) to install more than 2,200
photovoltaic systems [50] in dwellings from decentralized areas.
1.3 REVIEW OF THE DEVELOPMENT OF THE PHOTOVOLTAIC RURAL
ELECTRIFICATION
1.3.1 Introduction
During the second half of the nineteenth century, the rising cost of coal led to the exploration of
other alternatives to replace the coal in industrial applications where thermal processes intervene.
That was how the French professor M. Augustin Mouchot developed his solar thermal system, later
perfected by the engineer Frank Shuman in US in the early twentieth century [51] (see Figure 8).
After the First World War, oil prices dropped dramatically, putting an end to the new global energy
paradigm based on this fossil fuel while technological initiatives based on solar energy were
abandoned.

33. Chapter 1: Introduction
19
Figure 8: Left: 1878 Universal exhibition in Paris. First parabolic trough solar collector developed by
Mouchot in 1866; right: First solar‐generating plant set up in 1913 in Egypt at Maadi by Frank Shuman
The use of solar energy was absolutely forgotten for 6 decades until the 1970s, when the oil crises
of 1973 and 1979 shook the entire energy sector. Then the emerging photovoltaic technology, at
the time restricted to aerospace since in the 50s, Bell laboratories in US developed the first
photovoltaic cells, making the jump to terrestrial applications. This coincided with the first steps in
the manufacture of silicon cells at a much lower cost than existed to date (in 1971, the price of
silicon photovoltaic cells for the aerospace industry was $100/Wp [51]).
Since then, the use of photovoltaics was conceived as a possible solution to electrification in
remote areas. On the one hand, the solar resource is available, to a greater or lesser extent,
everywhere in the World and on the other hand, the photovoltaic module is an element of high
reliability and long life, which makes it ideal for use in isolated areas.
Despite these two great qualities, there have been other factors that have played against the
supposed "idealism" of the photovoltaic technology, such as high costs or low reliability of the
other system components. These negative factors have been evolving during the 40 years of PV
history thanks to the efforts of industry, researchers, installers and especially the users, who
throughout the world have been the great laboratory of the decentralized PV electrification.
1.3.2 The Solar Home System in Photovoltaic Rural Electrification
Although the global PV market is currently shared by around 99% dedicated to the grid‐connection
and only 1% (see Figure 9) to off‐grid applications, the use of PV technology in stand‐alone systems
was, until 2000, the most extended application, mainly to provide electricity (lighting and small
appliances) to rural homes through the so‐called solar home systems (SHS). The PV rural
electrification is currently growing annually at a rate greater than 20% [52]. For example, the off‐
grid PV systems power installed in 2013 may have been more5
than 600 MW (with 500 MW
installed in China alone) [53].
5
The author have not found any source reporting reliable data about global off‐grid PV markets

34. Chapter 1: Introduction
20
Figure 9: Evolution of the off‐grid and grid‐connected global market. The worldwide cumulated PV installed
power at the end of 2014 was 177 GWp
The solar home system has been the most used concept for mass electrification of houses in
remote areas, versus the centralized PV systems (pure or hybrid power‐plants) or commonly so‐
called mini‐grids (Figure 10).
Figure 10: Left: Village electrified by SHSs; Right: PV off‐grid power plant (both in Morocco)
The idea in favour of SHS argues that PV users invariably consume more electricity when they are
not personally responsible for the system. This concern is linked to the capacity and size of the
systems, to which the operation and maintenance factor could be added. The management of
collective structures (need of local organizations, agreements, etc) seems to be more difficult than
individual systems. However, SHS has also been imposed versus the mini‐grids for the following
reasons:
0
20
40
60
80
100
120
140
160
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
% Grid‐Connected % Off‐Grid Cumuled GWp GWp

35. Chapter 1: Introduction
21
 Standardization. The same design can be used in different homes or applications of similar
ranks, which makes it easier for engineers, developers and installers;
 Geographical spread. SHS can be applied in both dense and sparse populations. Mini‐grids
are justified only in geographically dense villages;
 Local availability of spare parts. SHS components are more standardized than those of mini‐
grid power plants, so it is easier to find spare parts locally in countries where PVRE is
developed, such as electrochemical batteries, regulators or light bulbs adapted to the SHSs.
An SHS is typically made up of (Figure 11) a small PV generator (35 – 100 Wp), a charge controller,
an electrochemical lead‐acid battery, several lamps and DC plugs to connect low loads, such as TVs,
radios or mobile phone chargers. These systems are usually set up to a 12 Vdc output [54].
Figure 11: Left: Solar Home System electric scheme, right: PV module of the SHS on the dwelling roof
Even though photovoltaic technology applied to rural electrification has reached a solid maturity
after 40 years of development, it still faces several problems, some of which are dealt with in this
thesis. These problems involve not only the body of the technology itself, the SHS (what we are
going to call hardware), but they mainly affect the management of decentralized services in rural
electrification (known as orgware).
To understand this issue we consider the two approaches presented below:
1.3.3 SHS: electrification system or domestic appliance
Taking into account the millions of SHSs that are installed in the world, it can be said that they
consist of a standardized assembly of basic components (generator, charge controller, battery and
loads). The user, in accordance with his economic resources, can purchase an SHS, and even install
it himself in exchange for an equipment warranty. This is something very similar to buying a
domestic appliance.
To refer to an SHS as an electrification facility, similar to the conventional power grid, it must satisfy
certain requirements, which make it equivalent to the electric power grid.
The electrical service from the conventional power grids is managed by large companies that
ensure the supply through a strong system of generation, transmission, distribution and O&M. The
resources of these companies range from sophisticated media and control management to
departments with specialized technical staff, mobility and transport capabilities, intervention

36. Chapter 1: Introduction
22
protocols, etc. A similar deployment of resources is used for commercial issues, for example to
ensure the collection of fees to end users by means of precise energy meters, switches to which
only the companies can access, direct debit payments, billing departments, etc.
In PVRE, it is difficult to obtain these sophisticated, large and effective management tools, perhaps
due to the limited size of most of the PVRE programs, when compared with the grid, which does
not apparently justify the necessary investment. While, in general, some PVRE programs
demonstrate meticulous care in terms of the quality of the devices, they pay little attention to the
management mechanisms that must ensure the operation and maintenance of the SHSs. So it can
guarantee the quality of the PV system but not its sustainability.
As a response to this problem, many electrification experiences have considered PVRE as
something further from a service notion and closer to a domestic appliance. Thus, the figure of the
service manager is replaced by the figure of the sales and guarantee manager. This model is a copy
of the common domestic appliance market, which has the peculiarity that it has been
institutionalized within the rural electrification field.
As an example for purposes of illustration, PVRE can be compared to bicycle hire services that exist
in many European cities. The purpose of this service is to provide mobility to citizens by means of
bicycles. The bikes are apparently similar to those that we have at home, but they have certain
special features, such as the automatic identification codes for tracking, parking anchorage devices,
etc, which make them different and adapted to a management system. The user rides the bike just
like a normal one, but in parallel to a registration system, subscriptions, card payments, etc. Behind
it there is a complex (and usually expensive) management system that allows the concessionaire to
carry out the O&M of bicycles and renting facilities, and to collect the leasing charges with
guarantees (obviously the correct use of bicycles and the collection of fees is not left to the good
faith of users).
To date it has been usual in PVRE for, even in programmes configured as electric service, the SHS to
be set up in a similar way to the bicycle that we have at home, in accordance with the
aforementioned example. Thus, the O&M managers of these systems do not have any tool to
manage the service offered to their customers and there is no choice but to trust in the honesty of
thousands of SHS's users.
The result of this fact is the well‐known dilemma about whether an SHS is a domestic appliance or,
on the other hand, an electrification system comparable to the conventional one [55]. If the
tendency is to achieve the universality of the access to electricity rights, the SHS cannot be a simple
appliance purchased by the user from any dealer. If the SHS is a real electric supply system, its set
up cannot be simplified to the minimum required components, and in the same way as the public
service of bicycle renting, it will need hardware (the SHS) adapted to the management system
(orgware) to provide the necessary tools to administrate the O&M and allow the user to benefit
from a service with the same guarantees given by conventional electrification.
1.3.4 PVRE as technological system
As regards the photovoltaic rural technology, understood as a system [56], from a holistic point of
view it consists of three dimensions (Figure 12):

37. Chapter 1: Introduction
23
The hardware (HW), that refers to the system material body: the SHS, its components, quality,
lifetime, reliability, cost, etc.
The software (SW) is about the use of the system by the user: the consumption, the time of use of
each appliance, the signals of the charge controller and reaction of the user, etc.
The orgware (OW) is the organization model of the rural electrification programme, which provides
the electricity service to the dwellings. In this regard it is taken into account on the one hand,
whether the programme is developed through subsidies, credits, cash sales or a fee for service,
among others. On the other hand, the orgware dimension deals with programme management,
from marketing and installation of the SHSs, to the "after sales" service and the operation and
maintenance.
Figure 12: Hardware, software and orgware interactions in the photovoltaic rural technology system
This scheme, proposed and analyzed for technological systems by the Ukrainian Gennady M.
Dobrov [57] in the late 1970s, has certain peculiarities concerning the 3‐dimension interaction. One
of them is that, traditionally in technical innovation, more attention has been paid (and more
resources dedicated) to the HW and SW than the OW. This negatively affects the technological
system’s sustainability. The orgware, defined by Dobrov as "a set of organizational arrangements
specially designed and integrated using human, institutional and technical factors to support the
appropriate interaction of the technology and the external systems", plays a key role in photovoltaic
rural technology, which has been underestimated throughout PVRE history and currently still
suffers significant deficiencies.
The element that perhaps has evolved most in the PV rural system has been the hardware, both in
the quality of the SHS devices, and adaptation of international standards, and recently, in the
dramatic reduction in market cost.
•SHS components
•Quality
•Prices
•Reliability
•Installation
•User SHS know‐how
•Consumption
•SHS interface
•User manual
•Financementmodel (subsidies, credits, cash sales, fee
for service, etc)
•Normes, tenders, engineering
•ESCO: marketing, installation, O&M, fee collection
•Internal skills and training
•Management structure
•O&M management
and costs
•Datalogger
•Monitoring
•Prepayment system
•Technical standard
•Spare parts
•Enquiries
•User skills
•Fee payment
•O&M fees
•Maintenance service
HARDWARE
ORGWARE
SOFTWARE

38. Chapter 1: Introduction
24
Second, the development of the software dates back to the beginnings of PVRE, when the task of
accommodating the needs and abilities of users to the management and operation of the PV
systems was the first requirement for the successful implementation of this technology. This has
remained until today, constantly adapting to new hardware advancements.
As regards the orgware, despite its developmental delay in PVRE, some of the factors that integrate
it have reached a high degree of maturity. Several management and organizational models have
been well described in the literature and applied in the field, especially since the 1990s, and they
have been studied in depth by recognized international organizations such as the World Bank [17,
58, 59, 60, 61, 62, 63, 64] or the International Energy Agency [65, 66, 67]. However, the orgware
has had several weak points during the development of PVRE, as will be discussed below.
1.3.5 Evolution of the HW, SW and OW in PVRE
1.3.5.1 The 1960s and 1970s. Hardware development: reliability and cost‐ effectiveness
in decentralized rural electrification
The first terrestrial experiences of PV technology date back to the 1960s when Japan began to use
it in maritime applications (light beacons, communications, etc) [68]. Paradoxically, oil companies
such as Exxon, Texaco and Shell, among others, pioneered the use of photovoltaic solar energy.
These companies had equipped their platforms in the Gulf of Mexico with lighted beacons, which
were fed from non‐rechargeable batteries which were frequently replaced, at an operating cost of
about US$2,100 per replaced battery. In the 1970s, these companies decided to change these
accumulators for rechargeable batteries with a photovoltaic generator, thus reducing the operating
costs by 95%.
It was in 1968, in Niger, when PVRE started formally, through the installation of a system to feed a
television in the Gondel school, close to Niamey [69]. The experience was expanded to other
schools until 1977, after installing 123 PV systems. They were made up of a 282 watt peak (Wp)
photovoltaic power generator, a 40 ampere‐hour (Ah) and 32 nominal volt (V) battery, and a charge
controller to feed a television receiver of 32 W. The cost of these systems was US$3,100 per school
in 1975, with an estimating price of US$0.12/hour of television, which meant US$3.75/kWh.
Despite this enormous cost and considering that the lifetime of the PV system was 10 years (PV
manufacturers at the time gave 5‐year warranties), the solution was 4 times cheaper than the
option of using high‐capacity alkaline cells, for which the TV receivers were originally designed.
In the 1970s, Father Verspieren in Mali [70], and his organization Mali Aqua Viva [71], instigated
the first photovoltaic pumping systems programme for extracting water from wells, in order to try
to solve the disastrous situation of thousands of people affected by the severe drought that
suffered the Sahel region in those years. The use of PV pumps by Verspieren was the result of years
of bad experiences with hand pumps and diesel generators because of their low reliability and high
O&M costs. Mali Aqua Viva carried out the installation of 16 PV pumping systems (reaching a total
power of 21.8 kW) between 1975 and 1980, which was one of the first milestones of PVRE to
consolidate this technology as a cost effective and reliable alternative to diesel generators and
hand pumps.

39. Chapter 1: Introduction
25
1.3.5.2 First promotion and R&D programs to reduce the costs of PV
The oil crisis was the trigger for the first political incentives for industry and research into
photovoltaic technology and its application in rural electrification. As PV was still a technology with
high manufacturing costs, a first researching phase focused on the cost reduction was necessary.
Some of these initiatives were as follows:
 In 1975 the Commission of the European Communities financed the first R&D program in the
field of non‐nuclear and non‐fossil fuel energies. It devoted US$6.4 million to photovoltaic
conversion [72], with the aim of studying and enhancing the photovoltaic cells, to later
evaluate them in several 5 kWp prototype systems [73].
 In 1976, the Department of Science and Technology of the Government of India launched their
Solar Cell Programme Plan with the aim of researching and developing different projects in
areas such as the "development of conventional type single crystal silicon solar cells" to get 7‐
9% PV conversion efficiencies. The programme was motivated by the low rate of access to
electricity in India (less than 10% of the rural inhabitants). They took PV energy into account as
a technological and cost‐effective solution, as alternative to the electric grid extensions. At the
time a cost of US$60 billion was estimated to mass electrify 100% of the population at 1 kWp
per dwelling [74].
 In the mid 1970s Mexico had a rural electrification rate of 35% (10.7 million people without
access to electricity). The Centro de Investigación y de Estudios Avanzados of the Instituto
Politécnico Nacional carried out some projects for PV terrestrial applications against the
background of the rural electrification problem. In 1976 two pilot projects were established:
"the demonstration project in educational TV" and "PV for two rural telephone stations", both
in the East of the Mexican Rocky Mountains, using PV modules of 7 Wp and 12‐15 V with 10%
efficiency [75].
 In Japan, also in the 1970s, the "Sunshine Project" had the final goal of reducing the cost of PV
by a factor of 100 through 5 fields of research: silicon ribbon crystals, silicon thin film, new
types of solar cells, II‐IV compound semiconductors and fundamental research [76].
 In the same vein, the UK Department of Industry (DIn), the Science Research Council and the
European Economic Community (EEC), started research work in the field of the PV cells in the
1970s a with the aim of reducing the manufacturing costs by half (less than £8/Wp) by means
of the development of new manufacturing processes of photovoltaic cells [77].
By the mid‐1970s the first pilot projects began, which aimed to direct PV technology applications
towards decentralized electrification, integrating the software dimension while its purpose was to
electrify remote rural populations:
 In 1976 in the USA, the "PV Stand‐Alone Application Project", led by the NASA Lewis Research
Centre and the United States Agency for International Development (USAID), developed
"universal" stand alone PV systems in order to open up a new market for rural electrification in
developing countries for domestic lighting applications, water pumping, grain mills, etc. [78,
79, 80, 81].
 In 1978 The United Nations Development Programme (UNDP) and the World Bank (WB)
launched the UNDP funded GLO/78/004 project to develop small‐scale pumping systems for
water supply and irrigation applications in developing countries [82], including field trials of
systems in Mali, the Philippines and Sudan.