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Journal of Energy in Southern Africa

On-line version ISSN 2413-3051
Print version ISSN 1021-447X

J. energy South. Afr. vol.22 n.1 Cape Town  2011


Development of a universal DC power supply using solar photovoltaic, utility and battery power sources



Joe Oladosu OniI; Bukola Olalekan BolajiII

IDepartment of Electrical/ Electronics Engineering, Olabisi Onabanjo University, Ibogun Campus, Ogun State, Nigeria
IIDepartment of Mechanical Engineering, University of Agriculture, Abeokuta, Nigeria




In this paper, a universal direct current (DC) power supply system was developed and tested in order to provide uninterrupted power for DC appliances. The system employs simple Diode OR logic for the three power sources (mains from utility power supply, the solar photovoltaic and battery). The parallel combination of the three diodes at the output functions like a comparator circuit and compares the outputs voltage of the three sources, so that the highest voltage at a particular time feeds the DC output and supplies the charging current to the battery. The universal DC power supply system was tested under various operating conditions and the results obtained showed a good performance of the system. The system outputs, when all the power sources were available, during utility power failure and when only the stored energy in the back-up battery was available were 13.8, 13.1 and 12.2V, respectively. The system guarantees an uninterrupted power supply, which can be used to power telecommunication equipment, audiovisual materials, computers, DC motor driven devices and other DC appliances. A typical day solar radiation varied from 547 W/m2 to 865 W/m2 while the generated voltage from PV varied from 11.8 V to 13.7 V. The generated voltage from solar power source increases with the increase in solar radiation.

Keywords: battery, direct current, photovoltaic, power, solar, universal



Full text available only in pdf format.




Adu, M.R. and Bolaji, B.O. (2004). Possibility of rural electrification through solar energy in Nigeria. Proceedings of 5th Annual Engineering Conference of School of Engineering and Engineering Technology, Federal University of Technology Minna, Nigeria: 105-111.         [ Links ]

Albrecht, J. (2007). The future role of photovoltaics: a learning curve versus portfolio perspective. Energy Policy, 35: 2296-2304.         [ Links ]

Aziz, A., Kassmi, K., Olivie, F and Martinez, A. (2006). Symbolization of the electric diagram of the marketed solar panels. Moroccan Journal of Condensed Matter, 7(1): 38-41.         [ Links ]

Bamiro, O.B. and Ideriah, FJ.K. (1982). Determination of the optimum collector orientation for Ibadan, Nigeria. Nigerian Journal of Solar Energy. 2(1): 26-32.         [ Links ]

Beshada, E., Bux, M. and Waldenmaier, T. (2006). Design optimization of a photovoltaic powered grain mill. Agricultural Engineering International: The CIGR Ejournal, 8: 1-15.         [ Links ]

Bolaji, B.O. and Adu, M.R. (2007). Design analysis of a photovoltaic pumping system for rural application in Nigeria. International Journal of Agricultural Sciences, Science, Environment and Technology, University of Agriculture, Abeokuta, Nigeria, Series B, 6(2): 120-130.         [ Links ]

Carr, A.J. and Pryor, T.L. (2004). A comparison of the performance of different PV module types in temperate climates. Solar Energy, 76: 285-94.         [ Links ]

EIA, (2004). Energy Information Administration, Electric Power Annual. Annual Electric Generator Report database, USA.         [ Links ]

Eltawil, M.A. and Samuel, D.V.K. (2007). Vapour compression cooling system powered by solar PV array for potato storage. Agricultural Engineering International: The CIGR Ejournal, 9: 1-23,         [ Links ]

Fagbenle, R. (1991). Optimum collector tilt angles and average annual global radiation for Nigeria conditions. Nigeria Journal of Renewable Energy. 2(1): 9-17.         [ Links ]

Jones, A.D. and Underwood, C.P (2001). A thermal model for photovoltaic systems. Solar Energy, 70: 3639-3644.         [ Links ]

Khedari, J., Waewsak, J., Supheng, W. and Hirunlabh, J. (2004). Experimental investigation of performance of a multi-purpose PV-slat window. Solar Energy Materials and Solar Cells, 82, 431-45.         [ Links ]

Klein, S.A. (1996). TRNSYS Users Manual Version 14.2, University of Wisconsin Solar Energy Laboratory, Madison, WI.         [ Links ]

Meyer, T. and Luther, J. (2004). On the correlation of electricity spot market prices and photovoltaic electricity generation. Energy Conversion Management, 45: 2639-2644.         [ Links ]

Nemet, G.F (2006). Beyond the learning curve: factors influencing cost reductions in photovoltaic. Energy Policy, 34: 3218-3232.         [ Links ]

Ordenes, M., Marinoski, D.L., Braun, P. and Ruther, R. (2007). The impact of building-integrated photovoltaic on the energy demand of multifamily dwelling in Brazil. Energy and Buildings 39: 629-642.         [ Links ]

Park, K.E., Kang, G.H., Kim, H.I., Yu, G.J. and Kim, J.T. (2010). Analysis of thermal and electrical performance of semi-transparent photovoltaic (PV) module. Energy, 35, 2681-2687.         [ Links ]

Q-Kou, S., Klein, S.A. and Beckman, W.A. (1998). A method for estimating the long-term performance of direct-coupled PV pumping systems. Solar Energy. 64(1): 33-40.         [ Links ]

Thomachan, K. and Srinivasan, K. (1996). Photovoltaic panel generator based autonomous power source for small refrigeration units. Solar Energy, 56: 543-552.         [ Links ]

Tiwari, G.N. (2002). Solar Energy Fundamentals, Design, Modelling and Applications. Narosa Pub. House, New Delhi.         [ Links ]

Tripanagnostopoulos, Y., Nousia, T. and Souliotis, M. (2001). Test results for air cooled modified PV modules. Proceedings of 17th European PV Solar Energy Conference Munich, Germany, 2519 - 2522.         [ Links ]



Received 15 July 2009
Revised 13 August 2010

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