Performance analysis of a solar chimney power plant for rural areas in Nigeria

Diverse renewable energy technologies are urgently needed, especially for developing countries. This paper aims to create awareness of solar chimney power plants (SCPP) as a viable and sustainable alternative in rural communities with limited or no access to the grid. The study considers site-specific hourly meteorological data in assessing the feasibility of SCPP in seven selected regions in Nigeria. A theoretical model was established for power output, levelized cost of electricity (LCOE) and avoided carbon emission predictions. Additionally, the effects of seasonality on solar radiation, ambient temperature, and power output were examined. The results show that SCPP with a collector diameter of 600 m and a chimney height of 150 m would produce an average power of 154-181 kW on a typical day under Nigeria conditions. Considering a lifetime of 40 years, LCOE varies from 0.216 to 0.254 (sic)/kWh compared to 0.563 (sic)/kWh for the widely-utilized diesel generators, and the annual carbon emissions mitigated varies from 162 to 191 tons. Moreover, the analysis suggests that the proposed SCPP would improve the social, economic and environmental development in the regions. Overall, the study shows that SCPP could be utilized to enhance energy access in the rural areas of Nigeria

Economic feasibility of solar PV system for rural electrification in Sub-Sahara Africa

The future of solar photovoltaic (PV) systems as a viable alternative to conventional fossil fuel-based resources seem promising with the rapid decline in the cost over the last decade. Notwithstanding, PV technology is yet to make a meaningful contribution in Sub-Sahara Africa (SSA) where the need for energy is deemed critical. The reason being that the technology is perceived by policymakers in SSA not to be capable of functioning profitably as an independent economic unit that requires project financing. Regrettably, the widely utilized levelized cost of energy (LCOE) in the literature for PV economic assessment only provides a benchmark to assess grid parity. A detailed economic assessment that includes risks and actual capital financing method is urgently needed to encourage potential investors and foster adoption. In this paper, a generalized economic model is developed to assess the cost-benefit of off-grid PV system. The developed method is demonstrated on a case study of rural Gusau, Nigeria. The results show that the feasibility of the proposed system is highly location dependent. Overall, conclusion is drawn that PV technology is eligible for project financing as it can repay its loan within the stipulated time considering the current infrastructure and energy policies in Nigeria

The performance and ranking pattern of PV systems incorporated with solar trackers in the northern hemisphere

Energy produced from a typical PV panel with or without solar tracker is mainly dependent on the available solar irradiance. Interestingly, for some locations on nearly the same latitude in the northern hemisphere, the solar irradiance varies significantly resulting to change in the ranking pattern of solar PV trackers. For this reason, the present study aims to explore the effect of solar irradiation on the technical and economic performance of PV panels incorporated with different solar trackers. Particularly, this paper focuses on locations classified as medium and high latitude countries (20-70 degrees N) in the northern hemisphere. While the considered locations in the northern hemisphere cover the continent of Europe, Africa, Asia, and North America, the studied solar trackers include dual/full/2-axis and single/one-axis (with several tracking orientations namely; East-West, North-South, Inclined East-West, and Vertical-Axis) trackers. The performance metric indicators of the energy gain and levelized cost of electricity (LCOE) are utilized to depict the most preferred solar tracking option for implementation in those regions. Overall, the observed ranking patterns are expected to guide not only solar PV project designers and engineers but also policymakers in the selection and implementation of suitable trackers in the regions

Optimal sizing of stand-alone photovoltaic systems in residential buildings

Solar photovoltaic (PV) system is one of the matured solar-to-electricity conversion technologies with a great potential for residential applications. For wider adoption of PV systems, there is a need for an accurate sizing and economic assessment tool to inform decision makers. In this study, we propose a new optimization model based on integer programming for the adoption of stand-alone PV systems in the residential sector. The proposed model not only determines the optimal number of PV modules and batteries but also assesses the economic feasibility of the system through annualized cost. The model takes into account site-specific data in finding the optimal sizes. The effectiveness of the proposed model is assessed through a case study in Bursari, Nigeria. The result obtained from the model reveals that establishing a solar PV system is not only environmentally friendly but also about 30% cheaper than the diesel generators that are currently in use at Bursari. In particular, annually about 361 USD per residential building could be saved if the proposed system is used to replace the diesel generators. Finally, this study also, provides valuable managerial insights about the effect of several parameters on the performance of the proposed PV system

The effect of latitude on the performance of different solar trackers in Europe and Africa

In this paper, the effect of latitude on the performance of different solar trackers is examined. The hourly solar radiation data of different locations around Europe and Africa measured on a horizontal surface is collected and utilized. Widely validated Perez anisotropic model is used to predict the diffuse component of the solar radiation on an inclined surface. Different solar trackers namely, Full/dual-axis, East-West (EW), North-South (NS), Inclined East-West (IEW), and Vertical-axis (V) trackers are considered in calculating the available solar potential of the locations. The performance of the solar trackers in terms of the energy gain is ranked according to the area location latitudes. The results show that the tracking performance is highly dependent on the locations, thus changes with the latitude. The percentage variation among the implemented one-axis tracking options relative to dual-axis trackers ranges from 0.42% to 23.4%. Overall, the increase in the energy gain of dual-axis trackers compared to the optimal fixed panel for the locations varies from 17.72% to 31.23%, thus emphasizes the importance of solar trackers. Finally, the study is expected to aid designers in the selection and installation of appropriate solar trackers in the regions

Evaluating the solar resource potential on different tracking surfaces in Nigeria

In this study, the available solar potential of some selected locations in Nigeria on an inclined, single-axis (considering 6 tracking orientations) and dual-axis tracking surfaces are assessed using hourly radiation data. More accurate and widely validated Perez anisotropic and Koronakis isotropic models are adopted in the estimation of the diffuse component of the radiation on an inclined surface before integrating trackers. The method utilized in the simulation are compared and verified by the result from System Advisor Model (SAM) before carrying out the detail resource assessment. The annual solar resource potential for the locations on a fixed surface inclined at an optimal angle ranges from 1621 to 2279 kW h m(-2), with the use of solar trackers; the yield would vary from 1664 to 2983 kW h m(-2). This amount of energy, if fully harnessed, would not only help in narrowing the gap between energy demand and supply but also would make a significant contribution in enriching the energy generation mix of the country. The increase in the annual energy yield of the dual-axis tracker compared to the other trackers and fixed tilted at optimal angle orientations ranged from 1.86% to 31.52%. Overall, the study is expected to provide a practical guide to aid designers and installers in the selection and implementation of suitable solar trackers in the country

A new economic feasibility approach for solar chimney power plant design

Solar chimney power plants have been accepted as one of the promising technologies for solar energy utilization. The objective of this study is to propose an effective approach to simultaneously determine the optimal dimensions of the solar chimney power plant and the economic feasibility of the proposed plant. For this purpose, a two-stage economic feasibility approach is proposed based on a new nonlinear programming model. In the first stage, the proposed optimization model which determines the optimal plant dimensions that not only minimize the discounted total cost of the system, but also satisfy the energy demand within a specified reliability taking into account the stochasticity of solar radiation and ambient temperature is solved using a commercial optimization solver that guarantees finding the global optimum. In the second stage, the net present value of building the plant is computed by deducting the discounted total cost found in the first stage from the present value of revenues obtained due to selling the electricity generated by the plant. The proposed approach is novel because it determines the optimal dimensions of the plant together with its economic feasibility by taking into account the energy demand and uncertainty in solar radiation and ambient temperature. The proposed approach is applied on a study in Potiskum, Nigeria, which reveals that building a plant with a collector diameter of 1128 m and chimney height of 715 m to Potiskum would be profitable for investors at an annual rate of return of 3% and would provide electrification to about 7500 people with a high level of reliability. The proposed approach is benchmarked with an intuitive approach and an approach that does not consider uncertainty in solar radiation and ambient temperature. The results clearly revealed the value of the proposed approach. Managerial insights on the impact of the efficiency of the collector, the efficiency of the turbine, electricity price, electricity demand, meteorological conditions, and discount rate on the size of the plant and the net present value are obtained through detailed sensitivity analyses

Optimal sizing of storage tanks in domestic rainwater harvesting systems: A linear programming approach

This paper proposes an optimization model to determine the optimal tank size of a single residential housing unit for rainwater harvesting and storage. Taking into account the site specific data such as the rainfall profile, the roof area of the building, the water consumption per capita and the number of residents, an integrated optimization model based on linear programming is proposed to decide on the size of rainwater storage tank to build such that the net present value of the total tank construction costs and freshwater purchase costs is minimized. The proposed model was tested on a case study from Northern Cyprus, the results of which emphasized the feasibility of rainwater harvesting as a sustainable supplement to the depleting aquifers in the region. The study also offers managerial insights on the impact of various parameters such as the number of residents, roof area, discount rate, water consumption per capita, unit cost of building the rainwater tank, and rainfall characteristics on the optimal tank size and on the net financial benefit gained from rainwater harvesting through detailed sensitivity analysis

Technical and economic assessment of fixed, single and dual-axis tracking PV panels in low latitude countries

This study aims to contribute towards developing a sustainable roadmap for electrification program via solar energy deployment in 21 low latitude countries (0-15 degrees N) with limited access to the grid. Firstly, the available electrical energy from fixed, single and dual-axis solar tracking PV panels is demonstrated using a case study of nine selected locations in Nigeria. The annual electrical energy for the locations from a fixed 1-kW PV panel tilted at an optimal angle ranges from 1485 to 2024 kWh, with the use of seven different single and dual-axis trackers; the yield would vary between 1521 and 2611 kWh. This amount of energy output, if fully harnessed, would contribute significantly to alleviating the chronic energy shortage in Nigeria. Finally, the performance of the solar trackers in terms of the energy gain and levelized cost of electricity (LCOE) is ranked to show the most preferred option for implementation. The presented ranking patterns can be used as a valuable guide by researchers and designers in the selection of the appropriate solar trackers for 21 low latitude countries located in three continents such as those around the Gulf of Guinea in Africa, the Gulf of Thailand in Asia, and the Caribbean Sea in America

Solar energy potentials in strategically located cities in Nigeria: Review, resource assessment and PV system design

Ensuring energy security increasingly requires expanding both yield and resilience of supply through source diversification. In this study, the current energy situation of Nigeria is presented through a detailed literature review. The survey reveals that access to the national grid is limited, and the power delivered to areas classified as urban with grid connection is very unreliable. An initial assessment of the potential utilization of solar based technologies for electricity generation is presented for three strategically located Nigerian cities of Onitsha, Kano and Lagos. These cities are known for their large commercial activities, and their frequent power outages hinder their business and socio-economic development. The solar resources are modeled using synthetic hourly meteorological data for a complete year in typical meteorological year format On an annual basis, Kano has the largest average daily global horizontal resources (6.08 kWh m(-2)), while these resources are practically equal for Onitsha (4.43 kWh m(-2)) and Lagos (4.42 kWh m(-2)). For dual axis tracking, which maximizes utilization of solar resources, the monthly range of daily average solar insolation for all locations varies between 3.65 kWh m(-2) and 8.00 kWh m(-2). A standalone photovoltaic system on a tilted surface is sized to meet a representative household demand based on intuitive and numerical simulation sizing methodologies. These sizing methodologies are general and can be applied to any location. The estimated PV capacity and the corresponding unit cost of electricity ranged from 1.26 kW(p) at 0.206 USD kWh(-1) to 2.92 kW(p) at 0.502 USD kWh(-1) for the selected cities. The results show that the unit cost of electricity from the proposed standalone PV systems is lower than that for the widely-utilized diesel generators. It is concluded that standalone PV electricity is technically and economically viable for urban residential application in Nigeria considering the current infrastructure and energy policies