ABSTRACT
There is a need for accurate knowledge of the performance, degradation rate, and lifespan of the photovoltaic (PV) module in every location for an effective solar PV power system. Outdoor degradation analysis was carried out on a mono-crystalline PV module rated 10 W using the CR1000 software-based Data Acquisition System (DAS). The PV module under test and meteorological Sensors were installed on a metal support structure on the same test plane. The data obtained was monitored from 09:00 to 18:00 hours each day continuously for a period of four years, from December 2014 to November 2018.The experiment was carried out near the Physics Department, Federal University of Technology, Minna (latitude 09o37’N, longitude 06o32’E, and 249 meters above sea level). The sensors were connected directly to the CR1000 Campbell Scientific data logger, while the module is connected to the logger via electronic loads. The logger was programmed to scan the load current from 0 to 1 A at intervals of 50mA every 5 minutes, and average values of short-circuit current, (Isc,) open-circuit voltage, (Voc), current at maximum power, (Imax), the voltage at maximum power,(Vmax), power and maximum power obtained from the modules together with the ambient parameters are recorded and logged. Data download at the data acquisition site was performed every 7 days to ensure effective and close monitoring of the data acquisition system (DAS). At the end of each month and where necessary, hourly, daily and monthly averages of each of the parameters-solar irradiance, solar insolation, wind speed, ambient and module temperatures, and the output response variables (open-circuit voltage, Voc, short-circuit current, Isc, the voltage at maximum power, Vmax, current at maximum power, Imax, efficiency, Eff, and fill factor, FF) of the photovoltaic modules were obtained.Yearly averages of the performance variables were obtained to ascertain the performance, degradation rate, and lifespan of the module. The module performance for the four years of study was compared with Standard Test Condition (STC) specifications. The maximum power achieved at 1000W/m2 for the four years of study are 0.711W, 1.82W, 0.50W, and 0.22W representing 7.11%, 18.39%, 5.0% and 2.25% of the manufacturer’s 10W specification. Module efficiency at 1000W/m2 for the four years of study is 3.30%, 10.12%, 3.98%, and 2.82% respectively as against the manufacturer’s STC specification of 46%. Accordingly, Module Performance Ratios for the PV module investigated were 0.072, 0.22, 0.087, and 0.061respectively. For the Rate of Degradation (RoD), it was observed that Open-Circuit voltage (Voc), Short-Circuit Current (Isc), Power-Output (P), and Maximum Power (Pmax), has an average yearly degradation rate of 1.06V, 0.002A, 0.082W and 0.142W representing 4.9%,0.30%,0.56%, and 1.4%respectively for the four years of study. The lifespan of the module was also determined through an empirically generated statistical model given as YEAR =4.60 -0.603Voc (v)-6.83Isc(A) +1.75 Power (W) was fitted to the observed data to predict the lifetime and yearly performance status of the module at any given year.
CHAPTER ONE
1.0 INTRODUCTION
1.1 Background to the study
Photovoltaic is a system of renewable energy based on the availability of sunlight all year round and has come to stay as part of the electrical energy mix in Europe, the United States, Japan, China, Australia, Nigeria, and many more countries. A solar cell is a device that converts energy from sunlight to electricity using the photovoltaic (PV) effect, this technology is one of the promising ways to achieve the rapidly increasing global electricity demanding with apollution- free environment. The reliability and durability of PV modules are of extreme importance for the reliability of the entire PV system, the solar-powered grid, promote the credibility of PV, and increase the investment in the PV industry. Besides, improving PV reliability contributes to reducing the leveled cost of electricity (LCOE) for PV-generated electricity.
The science regarding the reliability of PV modules is still immature(Pramodet al.,2016). There is not yet a complete understanding of what qualification test or test sequence is required to guarantee that a particular PV module would survive 25 years in a particular climate. It is well understood that the degradation rate or the lifetime of PV modules and systems are greatly influenced by the climatic conditions (Ezenwora, 2016), but the exact understanding of the influence of temperature, thermal cycling, UV exposure, relative humidity, or a combination of these is far from being completed. It is, therefore, necessary to build a database of real-world performance and reliability for estimating the leveled cost of electricity in different climatic conditions. Most degradation studies have so far been based on temperate and hot-dry climates due to the abundance of data in this type of climate.
It is important to know that the sun is the nearest star to the earth and therefore the source of all renewable energy on earth which provides sustenance for both plants, animals and also serves as the source for the solar system. Indeed, solar energy is used for industry, communities as well as individual needs. Over the past decade, the photovoltaic (PV) market has experienced unprecedented growth and besides these, the photovoltaic market has reached a cumulative installed capacity of roughly 40 GW worldwide, with an annual added capacity of 16.6 GW (EPIA, 2011). However, there is little information on PV module degradation in terms of frequency, speed of evolution, and degree of impact on module lifetime and reliability. Research on photovoltaic modules is rather focused on the race to develop new technologies to provide sufficient experience feedback on already operational technologies (Larondeet al., 2012; Tiwariet al., 2010 and Dubeyet al., 2010). For economic development in a society, the rate at which the demands for electricity will keep increasing as the population keeps increasing. Let us consider the present situation whereby primary energy account for 40% of the global energy used for power generation, and solar or renewable energy only account for 3.6% (Nasiror, 2018). It implies that the renewable energy demands that work needed to be done on it to be able to withstand higher population. The investigation of the performance evaluation and degradation rate of the monocrystalline photovoltaic module in the local environment will establish a degradation rate comparison between the locally available modules and the laboratory projection and a database will be generated where necessary.The result of these investigations will assist the designers, scientists, and Energy Research centers to get first-hand information on the performance of the module in the local environment before they proceed on design and installation for power supply.
1.2 Solar Energy availability
Solar energy has been harnessed by humans for thousands of years for heating purposes, and more recently for electricity generation. Solar power is an extremely vast resource, a good and accurate knowledge of the availability of solar radiation data in a location is primarily important for designing a system using solar energy by engineers and scientistsbut it has some limitations on availability that can affect its deployment around the world.The sun imparts a huge amount of sunlight on the Earth every day, and although about half of it is reflected by the atmosphere. The Earth absorbs about 3,850,000 joules of solar energy every year. More so, solar energy is absorbed by the Earth in one hour than the entire human population uses in one year.
Locations close to the north and south poles experience extended hours of sunlight, but it is only for a portion of the year, and they experience reduced hours of sunlight at opposite times of the year. Some solar power facilities employ energy storage systems to store excess power during off-peak periods and to deliver power during peak periods or overnight. Solar radiation is electromagnetic radiation and occurs over a wide range of wavelengths. The main range of solar radiation includes Ultraviolet (UV), 0.001- 0.4µm, Visible Spectrum (Light), 0.4 – 0.7µm, and Infrared radiation (IR), 0.7-100µm Solar radiation is fundamental to life on Earth, providing the ceaseless supply of energy that fuels nearly every ecosystem on the planet. Beyond making our very existence possible, energy from the sun has for decades attracted attention as a clean, renewable alternative to fossil fuels. Though at present it supplies only a fraction of global energy, the solar industry is a rapidly expanding component of the renewable energy sector. While debate certainly continues over the cost, practicability, and performance of industrial-scale solar installations, the technology offers much promise as a sustainable source of energy.
Each second, the sun turns a tiny fraction – half a trillionth – of this energy falls on Earth after a journey of about 150 million kilometers, which takes a little more than eight minutes. The solar irradiance, i.e. the amount of power that the Sun deposits per unit areaare 1368 watts per square meter (W/��2) at that distance. This measure is called the solar constant. However, sunlight on the surface of our planet is attenuated by the earth’s atmosphere, so less power arrives at the surface with about 1000 W/��2 in clear conditions when the sun is near the zenith. Our planet is not a disk, however, but a kind of rotating ball. The surface area of a globe is four times the surface area of a same-diameter disk. As a consequence, the incoming energy received from the sun averaged over the year and the surface area of the globe is one-fourth of 1 368 W/��2i.e. 342 W/��2. Of these 342 W/��2 roughly 77 W/��2are reflected in space by clouds, aerosols, and the atmosphere, and 67 W/��2 are absorbed by the atmosphere (IPCC, 2001). The remaining 198 W/��2, i.e. about 57% of the total hits the earth’s surface (on average). The solar radiation reaching the earth’s surface has two components: direct radiation, which comes directly from the sun’s disk; and diffuse radiation, which comes experienced as “sunshine”, a combination of bright light and radiant heat. Diffuse irradiance is experienced as “daylight”. On any solar device, one may also account for a third component – the diffuse radiation reflected by ground surfaces. The term global solar radiation refers to the sum of the direct and diffuse components.
In total, the sun offers a considerable amount of power: about 885 million terawatt-hours (TWh) reach the earth’s surface in a year, that is 6 200 times the commercial primary energy consumed by humankind in 2008 and 4200 times the energy that mankind would consume in 2035 following the IEA’s Current Policies Scenario. The unavailability of irradiation data for many places led to the development of various methods of estimating these parameters theoretically. (Sayigh,1977;Ugwuoke et al.,2005a) and The International Energy Agency (IEA) gave examples of the various relations that use meteorological data to estimate solar radiation.The most convenient and most widely used relationship is given by (Luhanga and Andringa, 1990; Ugwuoke,2005b; Ezanwora,2016).
The spectral distribution of light emitted by the sun extends from a wavelength of less than 0.3µm to 4.0µm (Leckner, 1978; Ezenwora, 2016).This is attenuated by at least 30% during its passage through the earth’s atmosphere. The causes of the attenuation include:
(i)The Rayleigh scattering or scattering by molecules in the atmosphere
(ii)Scattering by Aerosols and dust particles.
(iii)Absorption by the atmosphere and its constituents gases like oxygen, ozone, water vapor and carbon dioxide in particular.
1.3 Statement of the Research problem
It should be noted that consumers are becoming more and more interested in the reliability and lifetime of their PV system, though we have the lifetime of solar modules in works of literature but in most cases, it is a projection from the laboratory condition since the manufacturer’s specifications on solar panels are obtained under controlled laboratory condition known as standard test condition (solar irradiance of 1000 W/��2, Air Mass (AM) of 1.5 and operating temperature of 25�(C) (Kifilideen et al., 2018) or sometimes it is usually from a foreign climate zone other than ours which is not the true representation of the real conditions in which the PV devices have to operate. Research has shown that the output of PV modules differs significantly once exposed to outdoor conditions (Ryan et al., 2012: Ezenwora, 2016).Consequently, laboratory conditions are suspect and contestable, and actual outdoor evaluation as regards degradation rateand lifetime has not been done inMinna’s local environment since the atmospheric parameters that are responsible for the degradation changes with location.
Therefore, the need to study the rate at which atmospheric parameters affects the electrical parameters of monocrystalline PV modules in Minna local environment is important
1.4 Aim and Objectives of the study
The research is aimed at determining the yearly averagerate of degradation of electrical parameters of a monocrystalline photovoltaic Module in Minna, North Central Nigeria.
The Objectives of the research are to:
(i) characteriseand evaluate the performance of the monocrystallinemodules using four years of data obtained.
(ii) compare yearly performance variables of the module and deduce the rate of degradation using the four years of data obtained.
(iii) deduce empirically determined model for prediction of yearly performance and life span of the module in our environment.
1.5 Justification of the Research
Knowledge of the degradation rate and lifetime ofmonocrystalline silicon PV module will assist researchers, policymakers, PV energy designers, and installers in designing an effective PV power system best suitable for Minna local environment. It will equally give consumers firsthand information on what to expect from their PV power system before installation, comparative cost advantage and also energy payback.
1.6 Study Area
Photovoltaic effect availabilities on the earth’s surface are site dependents and vary throughout the year. It is only worthwhile installing solar radiation-based energy equipping an area where one can be reasonably assured of an adequate supply of such radiation. Minna is located in the latitude 09�36′50” North and longitude of 06�33′ 25″East at altitude 249 meters above sea level. The climate of the northern zone in Nigeria is characterised by two seasons which include, the wet (or rainy) and the dry seasons (Harmattan).The annual onset and cessation of the dry and wet seasons follow the quasi-periodic North-South to andfro movement of the inter-tropic convergence zone(ITCZ). The ITCZ demarcates the dry dust-laden North-East trade wind from the moisture-laden south-west trade. The dry season in the Sahel zone of Nigeria set in about October every year and persists till about May of the next year. This is the period when the ITCZ is displaced to the prevailing North-East trade wind. It transports large quantities of dust smoke from biomass burning into the atmosphere over the entire region (Anuforomet al.,2007).
Dust and smoke aerosols affect the climate system at local, regional and global scales in severalways. Due to its direct radiation impact, dust, aerosol effects, atmospheric temperature, thereby tampering with the vertical temperature distribution in the troposphere as a result of the changes in heating and cooling rates at different altitudes (Carlson and Benjamin,1980;Quijano,2000).The stability of the atmosphere is therefore affected bythesun (Ezenwora,2016;Bala et al.,2000).Based on the above facts, Minna canusesolar cells as an alternative to electricity generation. Figure 1.1 shows the map of the study area.
1.7 Scope and limitations
Since the performance and degradations rate of photovoltaic module greatly depends on location, this studyis carried out in Minna, North-Central Nigeria. The rate at which atmospheric parameters will affect its performance in Minna will differ from other locations. Those atmospheric parameters are solar irradiance, ambient, temperature, wind, and relative humidity which may influence the performance variables of open-circuit voltage, short circuit current, the voltage at maximum power, current at maximum, power output, and maximum power. There are different types of photovoltaic modules which include; Moncrystalline silicon, Polycrystalline silicon, and Amorphous silicon whichmay degrade differently to different atmospheric parametersbutthis research is only limitedtoMonocrystalline silicon.
This material content is developed to serve as a GUIDE for students to conduct academic research
DETERMINATION OF YEARLY PERFORMANCEAND DEGRADATION RATE OF ELECTRICAL PARAMETERS OF A MONOCRYSTALLINE PV MODULE IN MINNA, CENTRAL NIGERIA
Project 4Topics Support Team Are Always (24/7) Online To Help You With Your Project
Chat Us on WhatsApp » 09132600555
DO YOU NEED CLARIFICATION? CALL OUR HELP DESK:
09132600555 (Country Code: +234)
YOU CAN REACH OUR SUPPORT TEAM VIA MAIL: [email protected]
09132600555 (Country Code: +234)