International Journal of Green Technology, 2020, 6, 1-9 1
E-ISSN: 2414-2077/20 © 2020 International Journal of Green Technology
Assessment of the Viability of Standalone Photovoltaic Systems
for Rural Households in Kathiani, Machakos County, Kenya
B.O. Odhiambo
1,*
, D.W. Wekesa
2
, C.O. Saoke
3
and J.N Kamau
3
1
Institute of Energy and Environmental Technology, Jomo Kenyatta University of Agriculture and Technology,
Nairobi, Kenya
2
Department of Physics, Multimedia University of Kenya, Nairobi, Kenya
3
Department of Physics, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
Abstract: Access to reliable electricity is still a challenge in Kenya, especially among rural populations. Photovoltaic
technology is seen as one of the best alternatives in the provision of quality and affordable electricity. This research
aimed at assessing the solar radiation potential of Kathiani, Machakos County in Kenya with regards to the solar hours
and how such radiation can be converted to usable energy. It involved the analysis of average daily, monthly, and annual
solar radiation data for the region by use of PVGIS software. In the study, a survey to determine the energy requirements
of the area for effective sizing as per the consumers’ needs is carried out, by use of questionnaires, interviews and
observation. PV system sizing of a household is performed to ensure each component of the system meets load
requirements. In addition, the research involved an economic analysis of adopting standalone solar energy technology
as an alternative to grid connected electricity. This was achieved by analyzing the life cycle cost of the system to come
up with the unit cost. The study findings revealed that Kathiani region in Machakos, county Kenya receives adequate
average daily solar insolation of 5.42 kWh/m
2
, which has the potential of producing annual PV energy of 1521 kWh. This
implies that the region is economically viable for harnessing electricity through standalone solar PV systems.
Keywords: Solar insolation, Stand-alone PV, Energy Demand, Life Cycle Cost (LCC) Analysis, Unit costs.
INTRODUCTION
Electricity is essential for human life as it influences
every part of people's lives and is important to the
effective functioning of a healthy economy. Lack of
electricity is one of the major challenges facing the
contemporary world, with more than 1.8 billion being
unable to access electricity. Most of these people live
in rural areas as they are not able to afford life in urban
areas where the national grid is mainly available. In
these cases, electrification by means of solar systems
has aimed to be an effective solution [1]. Solar energy
is known to be a great renewable resource which can
help curb the environmental problems caused by
mostly used non-renewable energy sources.
For effective solar energy generation, solar
resource potential of an area should be established.
This involves solar resource data from meteorological
departments, as well as physical measurement
including such devices as Pyranometers,
pyrheliometers and solar data loggers. However, more
accurate data can be obtained by use of softwares
such as RETscreen, PVGIS, HOMMER, Solargis
among others. These softwares give hourly, daily,
weekly, monthly and yearly solar irradiation averages.
Energy demand analysis on the other hand requires
information regarding daily energy consumption of the
households. Questionnaires can be used to get
important information on electrical appliances in the
Address correspondence to this article at the Institute of Energy and
Environmental Technology, Jomo Kenyatta University of Agriculture and
Technology, Nairobi, Kenya: Tel: +254 724615830;
E-mail: barrack.amamo11@gmail.com
household, which would help establish load profiles for
the homes. This is important for effective sizing and
installation of the solar PV systems. The software
Hybrid Optimization Model for Electric Renewables
(HOMER 2.68 beta) is also widely used by researchers
in many countries as a modeling tool for optimal sizing
simulation of micro-grids on the advantages of rooftop
solar off grid system [2]. HOMER is an essential tool in
specifying optimal size of equipment taking into
account meteorological and geographical data of the
study location. It applies the Net present value method
for ranking a systems suitability. Various researchers
have used and analyzed various online tools and
databases with solar irradiation data such as PVWatts
by NREL [11], PVGIS by Joint Research centre [12],
Global atlas and Solargis. The study investigated their
benefits and challenges, pointing out that they have
made it easier to obtain accurate real time solar
irradiation data. However, the research concluded that
the online tools sometimes provide low-resolution data,
in the range of a few kilometers that require multiple
queries to the database in case large-scale analysis [3].
This research employs the use of PVGIS database to
estimate the potential of electricity production by PV
systems.
This study also involves economic analysis and
feasibility of solar PV. Here, various financial models
are used, including Life Cycle Cost (LCC) analysis, and
payback period. In as much as there has been
increased access and use of solar home systems, the
cost are still high. Solar Home Systems (SHS) have the
added cost of Batteries as well as lack of economies of
scale. This implies that most SHS are small systems of