Planning and Installation of 3.5 Megawatts Off grid Solar Hybrid Power Plant: A Case Study of the Joseph Sarwuan Tarka University Makurdi, Nigeria

Abstract

This report highlights the processes involved in the planning and installation of a 3.5 Megawatts solar hybrid power plant situated at the campus of the Joseph Sarwuan Tarka, University Makurdi, Benue State Nigeria. These processes include Photovoltaic (PV) cells installations, Inverter Installations, transformer installations, and the installation of string combiner boxes (SCBs).  The Solar Hybrid Power plant installed is a hybrid power system that uses a combination of solar PV cells, batteries, and diesel-powered generators as energy sources to meet the energy need of the various load centers on the University campus. The solar PV cells array serves as the primary power source while the diesel-powered generators serve as the power backup. Since the project is a hybrid installation, it becomes necessary to synchronize the power sources to increase the efficiency of the power supply and reduced downtime.

The back-ups are the three Diesel-powered generators labeled (DG1, DG2, and DG3) and the Battery Banks labeled (BBR1, BBR2, BBR3). The secondary power source turns ON automatically when the primary power source fails. During the installation of the primary source, rigid flat framed PV modules made of Poly-Crystalline were used because of its temperature resistive advantage. Twenty (20) PV modules were wired together in series to form a table, two tables connected in parallel to form a String. The result shows that the power of each panel used was 330W while the output voltage varies between 37.5 to 40.5 Volts. The total voltage per table was between 736 to 823 volts during the day. The total number of PV modules installed at the site was 12,140. Three sets of diesel Generators, comprising of two 1 MVA capacity and a 1.5 MVA capacity, all terminated at their respective transformers. Their output voltage is 0.415 kV each, terminating at the Low Voltage (LV) side of their respective transformers. The transformer steps it up to 11kV to supply the High Tension (HT) panel. 

The Minimum and Maximum PV power and load demand data obtained by the plant Supervisory Control and Data Acquisition System within one year period after installation shows the  Maximum and Minimum power at 2.5 MW and 1.75 MW, while the maximum and minimum load demand stood at 850 kW and 350 kW. The average daily power consumption stood highest at 900kW during weekdays and lowest at 200 kW during weekends.