Development Of A 5KVA Solar Microgrid System

ABSTRACT

Energetic isolation is one of the most wide-spread problems amongst rural communities in many regions  of the planet. Solar off-grid installations stand out as one of the best solutions to help these communities obtain access to electricity. The project consists development of a solar micro-grid for rural communities. The aim has been to design and dimension a viable project that considers all the phases and factors involved in the development and operation of a solar energy system in a remote area. These combine social, economic, infrastructural, logistical and technical considerations and requirements.

The first section of the thesis consisted in the study of the community with the aim of understanding its energy needs. These included researching on its location, access, number of appliances in the university, facilities, infrastructure, solar resources, etc.

A load profile has been determined based on the devices and loads present in Kwara State University. For the design and dimensioning of the electrical installation, the general structure of the circuit has first been determined, only to proceed to the election of each electrical component based on cost- effectiveness and performance indicators. Several energy-system optimizers have been useful to carry out the dimensioning of several components in the site. However, this study is aimed at development of a 5KVA solar micro grid system for rural electrification.

• Introduction

A microgrid is a distributed energy system consisting of resources and loads capable of operating in conjunction with or isolated from the main power grid. It has the power of meeting the increasing energy demand efficiently and flexibly, whether they are connected to the grid or not. It supplies reliable electricity without the need for expensive transmission infrastructure investments.

The microgrid in this paper serves a remote and non grid connected population. Reliable electrification is the basic infrastructure of development. In any developed country people cannot imagine life without electricity; minutes of blackout may cause millions of dollars in damages and lost revenue. That may not be true for developing countries (such as Nigeria) where 1.5 billion people are still living without electricity and almost 2 billion people depend on traditional biomass for their daily energy needs, such as lighting and cooking [1]. However, due to rapid migration to the urbanized areas governments are often focused only on such areas and remote rural places are still left out.

Electricity plays a major role in socio-economic development. Economic growth is directly or indirectly related to energy consumption. Therefore, there is a vast financial gap between people living in urban areas and remote areas. Development of alternative energy sources in these remote areas has the possibility to enhance the life of the people, increase employment opportunities and access to education of children. It also creates the possibility of carbon trading in the global market under the clean development mechanism (CDM) of the Kyoto protocol by reducing greenhouse gases.

This freely available water and solar energy can be converted into electricity. Water originating from the world’s highest peaks is underutilized as farmers residing a couple of meters above major rivers lack technology to pump water to drink and irrigate.

In order to move towards a sustainable existence in our critically energy dependent society, there is a continuing need to adopt environmentally sustainable methods for energy production. In Nigeria, as in most developing nations, the demand for sustainable energy is increasing due to population and developmental growth (Otun et al, 2012). Researches in this field have developed several methods of generating clean and affordable energy. Even though the use of fossil fuels for generation of electrical energy is more than the use of renewable sources, decreasing oil reserves in the world makes the potential for fossil fuels as a future resource of energy to be decreasing (Zehra and Muhsin, 2013). This leads to a significant interest in renewable energy sources therefore, making transition from fossil fuels towards renewable energy unavoidable (Zehra and Muhsin, 2013). The dependency on safe energy production system from renewable energy is increasing and gaining ground with the support from government policy around the world, especially with the instability of oil in the Middle East and the recent Fukushima nuclear disaster (Jungjohann and Rickerson, 2011). Renewable energy technologies offer the promise of clean, abundant energy gathered from self-renewing resources such as the sun, wind, water, earth and plants (Dorin et al, 2009). In most cases, one renewable energy system cannot fulfill the power requirement alone as it is intermittent in nature hence the solution is to hybridized the renewable energy systems (Meshram et al, 2013). To satisfy the power requirement, integration of the power grid is required. For supplying electric power in areas using this hybrid system, the power grid may be integrated. For the development of a system that will augment deficit of power, load forecasting is necessary.

According to the IEA (International Energy Agency) WEO (World Energy Outlook) 2017 estimates, almost 1.1 billion people—14% of the global population—do not have access to electricity, and more than 95% of them are in sub-Saharan Africa and developing Asia. Nigeria, despite making efforts to enhance electrification, only managed to reach an electrification rate of 47% in 2016. Looking at the current energy situation, there are still many challenges and weaknesses that affect the energy supply sector in Nigeria. The main ones are:

• low access to modern energy, especially for cooking, leading to high pressure on biomass resources;
• high cost of energy;
• energy demand increasing faster than the additional generation installation rate;
• high cost of rural electrification through grid extension due to the scattered nature of settlements; (v) frequent power outages and high system losses; and
• high dependence on imported petroleum fuels (Kiplagat and Wang, 2011). The Nigeria Government has developed the Nigeria Vision 2030 as the country’s new development blueprint.

The vision aims at transforming Nigeria into a newly industrializing, middle-income country providing a high quality of life to all its citizens by the year 2030, and has identified provision of energy as the key to meet its goals. Aligned to this strategy document, Nigeria has implemented the Energy Policy 2004, targeting to reach 40% electricity connectivity of the rural population by 2020, and has subscribed the UN Sustainable Energy for All Initiative and the manifesto of Jubilee Coalition (Nigeriatta, Ruto, Ngilu, Balala, Harmonised, 2013). To pursue energy access for all, the efforts are focused both on energy transmission and distribution, and power generation. Since the energy transmission is capital intensive and has hitherto concentrated in high population density and high economic areas, the Nigeria Government has installed off-grid diesel-based power stations and distribution mini-grids covering some remote rural areas for which the connection to the national transmission grid is not feasible. The systems based on diesel generation installed by the Ministry of Energy and Petroleum to supply electricity to areas which are far from the national grid have experienced several challenges, such as:

• the cost of fuel increases with the remoteness of the location due to logistic costs;
• on-site storage challenges;
• high operation and maintenance costs; and (iv) the gas emissions contribution to environmental pollution and global warming (CO2).

In 2010, the Ministry of Energy and Petroleum, through the Nigeria Power Company, commenced a pilot program to hybridize these off-grid power stations by installing renewable energy power sources, particularly wind and PV-solar. Currently, there are off-grid diesel power stations as well as pilot hybrid systems (solar, wind or solar/wind), and new installations by the Rural Electrification Authority (REA) are currently ongoing.

However, in this study we are focusing on the development of micro grid solar energy for rural communities.

1.2   Motivation

As the Ministry of Energy and Petroleum promotes the installation of hybrid stations in remote areas, it is fundamental to conduct an in depth technical assessment of the existing hybrid plants on their system reliability, the value for the investments and their current system performance to advise their optimization by using renewable energy resources and ensure the technical and financial sustainability. The outcome of this study will reinforce the policy making activities of implementing the hybridization program. Furthermore, this study aims at providing information about the use of mini-grids as a convenient solution to increase electricity access in remote areas. This information is required to provide impetus to upscale the installation of the microgrids. The study will also provide technical inputs on methods and ways of optimizing the micro grid for solar energy. It is important to identify the potential contribution of solar PV, as a replacement of diesel generators, to ensure rural development and gain further income and political commitment because such solar projects may expand to other areas and may help ensure solar PV is designed appropriately, under real-life environmental conditions.

1.3. Problem statement

The unavailability as well as the lack of sufficient electricity is still one of the main issues hindering socio-economic development in Nigeria, especially in its rural areas (Imad, 2019).

In some remote areas located in the Nigerian territories, diesel generators are still used to power homes and pump water for a limited period of time during a day. Therefore, a solar photovoltaic (PV) powered system can be a practical choice for power supply by utilizing solar PV systems.

This paper describes how a micro grid solar PV system with lead-acid storage batteries may be utilized for electrification. The upgrade of the existing system was carried out to provide more electricity access to the university.

Electricity access and pump water. In this paper, a solar PV system design for electrification presented, along with the techno-economic feasibility of substituting the existing diesel engines for solar photovoltaic (PV) systems. Solar PV systems were found to be more economic in comparison with diesel use.

1.4. Aims and objectives

The main aim of this work is to develop a 5kva micro-grid solar PV systems which can be used for rural electrification  instead of diesel generators.

The objectives of the study are:

1. To increase the rate of power supply in our society
2. To ensure a safe, reliable and affordable energy supply thereby supplying energy to appliances and instrument at any point in time

• study the impact of using micro-grid solar photovoltaic

1.5. Scope

Considering the photovoltaic power has the characteristic of stochastic waving, the microgrid composed of batteries storage energy and photovoltaic cells is adopted. A control system of three layers structure is designed, which are local layer, concentrating layer and center layer. The master-slave control mode is used for microgrid operation. The scheme has been used in the actual project; the whole system is operated well in terms of stability, reliability and economy. It provides an example of the photovoltaic cells used for electric power generation project.