Desalination 209 (2007) 39–42
Performance of photovoltaic solar system in Algeria A. Benatiallaha, R. Mostefaoub*, K. Bradjaa a
Labo sigaux & systems, Dept d’électronique, Faculté des sciences, University of Mostaganem, Mostaganem 27000, Tél./Fax +213 45 26 54 52 bDept de physique, U.S.T.Oran email:
[email protected]
Abstract The economic and social development in Algeria these last years has been needed a continues increasing in demand of electricity, especially in the isolate countryside. Large parts of the electric demand are in the Sahara areas (~80% of the total surface). These regions are characterized by a dispersed population, a very hot climate of strong radiations (~7 kw h/m2/day) and a low consumption of energy. The use of the conventional energy sources is very costs and the extension of electric networks finds enormous problems. The solar energy is adapted for this area and has been satisfactory results promote results for the future. A national program was establish since several years for the photovoltaic solar system installation in order to satisfy the domestic needs in electricity for a lot of villages, pumping of water and other economic activities (rural electrification of 20 village of 1000 habitation has been lanced in 2000). This system photovoltaic meeting many problems of adaptation and to be reliable and competitive (optimizes their cost), studies of their performance are necessary permitting to see the behavior and adaptation in conditions of sites as well as the climatic and social condition effect on the working and the profitability for a long time. Keywords: PV system; Performance; Experimental stand alone system; Climatic effect
1. Introduction Stand-alone photovoltaic system is established as a reliable and economical sources of electricity in rural and Sahara areas, especially in developing countries where the population is dispersed, has low consumption of energy and *Corresponding author.
the grid power is not extended to these areas due to viability and financial problems. In almost all developing countries of the world, the major proportion of the population living in the remote and isolated locations does not have access electric power. The power supplied by PV generator depends upon the insolation, temperature. The battery is
The Ninth Arab International Conference on Solar Energy (AICSE-9), Kingdom of Bahrain 0011-9164/06/$– See front matter © 2006 Published by Elsevier B.V. doi:10.1016/j.desal.2007.04.006
A. Benatiallah et al. / Desalination 209 (2007) 39–42
PV
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Fig. 1. PV system overview.
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2. System description The system is shown in Fig. 1. There are 30 PV module arranged in 3 parallel groups of 9 modules in series. Total module area is 12.78 m2. The array consists of monocrystalline modules from UDTS50. The modules are inclining by 28° from horizontal and oriented to south. The array DC output at STC (1000 w/m2, 25°C) is 1.5 kw, and the nominal efficiency is 12%. The solar energy is storage in batteries (nominal tension is 2 V) for the night and during periods no insolate. The regulator is a electronic device to control and protection of batteries, with very high efficiency around 99.57%. The PV system is connected to load composite by domestic components (5 lamps, refrigerator, radio, ventilator and television).
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Fig. 2. Mean monthly irradiance.
3. Data collection The global insolation for the site is shown in Fig. 2 for the horizontal plane and for the tilted plane. The radiation flux in this region is very important (the average is 7.2 kwh/j/m2). The ambient temperature values are illustrated on Fig. 3. Radiation was lower in November, December and January down to 6.05 kwh/m2/j because of low sunlight condition. Between June and September, the radiation was around 7.32 kwh/m2/j (days was longer) [1,2].
4. Results and discussion A set of measure ha been relived to the system with a variable consumption of load (according to the average consumption for habitation in Sahara area).
T°
necessary because of the fluctuating nature of the output delivered by the PV generator. The electricity produced by solar cells is direct current and it is converted to alternating current using an inverter. The paper describes the application of PV energy in south area of Algeria and performances of system for a long time. This paper presents evaluation of the performance of 1.5 kwc photovoltaic system installed on the south of Algeria (Sahara), and the performance of all the components of the system (PV array, maximum power point, inverter) is analyzed. Energy delivered to the load and system efficiency.
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Fig. 3. Mean monthly temperature.
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A. Benatiallah et al. / Desalination 209 (2007) 39–42 Rendement
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Fig. 5. Monthly array and system efficiency.
Fig. 4. Monthly array and system output.
5. System performance
(between 82.37 and 82.97%), because the summer days are longer than winter, and for use of ventilator (high temperature).
5.1. Photovoltaic array The performance of photovoltaic array is analyzed in Fig. 4, for the period January– December 2001. The array DC output varied from 3.512 kwh in December to 7.983 kwh in August. The monthly average efficiency is 10.07% during the same period. The efficiency was between 9.64–10.5% in December, July, when the solar radiation is high and in low temperature. Efficiency was lower in November (down to 9.64%) because of low insolation [3–5].
5.3. PV system Monthly system output and efficiency are shown in Fig. 6, the system delivers between 2.41 kwh (December 2001) and 6.22 kwh (August 2001). Total output is 49.71 kwh for this period [6–9]. Efficiency is around 9.31% from January 2001 to December 2001, and between 7.22–10.2% from this period. The curve dips in December from 7.22 to 8.26 in February because the inverter works less efficiently at low power and low irradiance [10].
5.2. Power conditioning (Inverter) Rendement onduler 86 84 Rc %
The inverter transforms the DC current from PV array into AC current. Fig. 5 shows the hourly efficiency of the power conditioner as a function of the DC power input. The curve shows that efficiency is around 80.66%. The efficiency decreases at low power of charge during winter months in the south, the inverter may operate a long period of time with less than 150 w from the PV array, thus consuming power and reducing its efficiency. For the rest of the year, the efficiency varies between 77.22% and 85.44%. Efficiencies are higher in summer (between 80.17% and 85.44%) than winter
82 80 78 76 0
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Fig. 6. Monthly inverter efficiency.
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6. Conclusion The PV system has worked reliably in this period. Generating a total output of 2.5 kwh for the period January 2000 to August 2000. Array efficiency is around 10.1% and can be as low as 7.2% during the winter months. The inverter has worked at higher efficiency 85.6%. The efficiencies of the PV modules are lower in summer than at other seasons because of low consumption of electricity and higher temperature of the site. The system no has working in the optimal point MPT because of low consumption of load and the high capacity of batteries. The storage is hyper sizing and the daily storage of electricity is sufficient is this area with high radiation. The temperature and wind degrade the performances of system, a regular cleaning of module is necessary. References [1]
[2]
Anil Cabral, Mac cosgrove, Best practices for photovoltaic household electrification. World bank technical paper-number 324. Universal technical standard for solar home systems; thermie B SPU 995-96, EC-DGXVH, 1998.
[3]
K. Preiser et al., Local production of components for PV systems, the case of the Bolivian Battery TOYO solar, proceedings of the 14th European PVC, 1997. [4] M.Gazela et al., A new method for typical weather data selection to evaluate long-term performance of solar systems, Sol. energy, 70(4) (2001) 339. [5] M. Camani, D. Chianese and S. Rezzonico, Proceedings 11th EC Photovoltaic Solar Energy Conference, Montreux (1992) 1235. [6] G. Travaglini, N. Cereghetti, D. Chianese and S. Rezzonico, Proceedings 16th EC Photovoltaic Solar Energy Conference, Glasgow (2000) 2245. [7] M. Camani, P. Ceppi and D. Iacobucci, Operational characteristics of the grid connected photovoltaic plant TISO 15, Mediterranean Electrotechnical Conference IEEE, Madrid (1985). [8] M. Camani, N. Cereghetti, D. Chianese and S. Rezzonico, Proceedings 14th EC Photovoltaic Solar Energy Conference, Barcelona (1997) 709. [9] N. Hammami, A. Ounalli, M. Njaimi, F. Esmii, M. Schulte, M. Jraidi, A.V. Meer and D. Ullerich, Solar Rural Electrification in Tunisia–Approach and Practical Experience, Volume 2 AME/GmbH Tunisia (1999). [10] M. Jraidi and A. Dhouib, Evaluation of the Performances of a Rural Electrification Photovoltaic System, World Renewable Energy Congress IV.
