ABSTRACT

With the alarming rate of depletion of the major conventional energy resources coupled with the environmental degradation caused by the process of harnessing these energy sources, it has become an urgent necessity to invest in renewable energy resources.

The best conversion efficiency of most commercially available solar cells is quite low ranging between 10% and 20% [1]. The goal of this thesis is to identify rooms and ways to improve this efficiency.

The main test specimen was a monocrystalline solar panel. A study was first carried out on the monocrystalline solar panel to study at what temperature the panel suffers drastic drop in efficiency. After this study, an automatic system was designed to monitor the panel temperature which was expected to spray water at 21⁰C on the panel by use of a jet sprinkler and a motor pump. Taking into consideration that the control system is powered by the energy supplied by the P-V power system, an energy analysis of the system was performed and it was established that the entire system is still on a positive margin even using the same source to power it.

Keywords;

• Photovoltaic
• Efficiency
• Temperature
• Monocrystalline

CHAPTER ONE

INTRODUCTION

1.1. Background and context of the study

Solar energy is clean and is abundantly available [1]. Solar technologies use the sun to provide heat, light, electricity, etc. for domestic and industrial applications. With the alarming rate of depletion of the major conventional energy resources such as Coal, Petroleum and Natural gas, coupled with the environmental degradation caused by the process of harnessing these energy sources, it has become an urgent necessity to invest in renewable energy resources that would power the future sufficiently without degrading the environment through greenhouse gas emission. The energy potential of the sun is immense, but despite this unlimited solar energy resource [1], harvesting it is a challenge mainly because of the limited efficiency of the array cells. The best conversion efficiency of most commercially available solar cells is in the range 10%- 20% [1]. Although recent breakthrough in the technology of solar cells show significant improvement but the fact that the maximum solar cell efficiency still falls in the less than 20% range shows there is enormous room for improvement. The goal of this thesis is to identify these rooms and ways to improving them. One of such ways is by water cooling the temperature of the solar cell. This is actually the basis of this work.

Cameroon has an abundant reserve of energy resources, such as crude oil, natural gas, hydropower, biomass, solar, wind and geothermal energies. However, these resources are still weakly valorized. The country relies mainly on hydropower energy for electricity generation (73%) with persistent power outages throughout the country especially in the dry seasons when water levels are low. Electricity access is about 65–88% in urban areas and around 14% for rural populations [2]. The potential of solar energy in Cameroon is high with an average estimated solar irradiance of 5.8 kWh/day/m² in the Northern parts of the country (42% diffused) and 4.9 kWh/day/m² for the rest of the country [2]. The national yearly average is about 4.2 kWh/day/m² [2]. This potential, however, is weakly valorized despite the availability of ideal conditions throughout the country. The main reason is the lack of dedication and commitments from the government to stimulate the sector. The Northern regions of Cameroon are endowed with a huge solar potential (Fig 1.2) that can be commercially exploited to help improve the electricity and energy problems in Cameroon. Cameroon has experienced a strong economic growth (growth rate of 5.9% in 2015), accompanied by a rapid increase in electricity demand (1455 MW in 2014). Electricity needs are expected to continue rising over the next decade to reach 5000 MW by 2020 and 6000 MW by 2030. [2]

1.2 Problem Statement

With the alarming rate of depletion by major conventional energy resources such as Coal, Petroleum and Natural gas, coupled with the environmental degradation caused by the process of harnessing these energy sources, it has become an urgent necessity to invest in renewable energy resources that would power the future sufficiently without degrading the environment through greenhouse gas emission. The energy potential of the sun is immense [1], but despite this unlimited solar energy resource, harvesting it is a challenge mainly because of the limited efficiency of the array cells. The best conversion efficiency of most commercially available solar cells is in the range 10%- 20% [1], Although recent breakthroughs in the technology of solar cells shows significant improvement but the fact that the maximum solar cell efficiency still falls in the less than 20% range shows there are enormous room for improvement. The goal of this thesis is to identify these rooms and ways to improving them.

1.3 Objectives of the study

This work was generally intended to study the different types of PV technologies and understand the behaviour of a ready-made photo-voltaic power system in terms of output efficiency and then look at the possible ways and methods to improve this efficiency. Our specific objective now was to improve the efficiency of the system by cooling. This was done automatically using a water jet sprinkler. Taking in to consideration that temperarure rise is a detrimental factor to output efficiency of PV power systems.