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 kWp at 0.206 USD kWh−1 to 2.92 kWp 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.