4. Analyses of main parameters affecting system performance
The main parameters affecting system performance are well head-flow rate characteristic, pump head-flow rate characteristic, solar radiation and PV power. Fig. 6 shows the daily pump power variation curve for the PV configuration (8S 3P). Fig. 7a shows the total systems efficiency for different experimental heads used. At the first observation from Fig.7a ,it is difficult to conclude which
5400 5600 5800 6000 6200 6400 6600 6800 7000
10 12 14 16 18 20 22 24 26 28 30 32
80 m 70 m 60 m 50 m
Daily Flow rate (m3/day)
Solar irradiation (Wh/m2/day)
Fig. 4. Daily flow rate vs. solar irradiation at various pumping heads.
Table 1 Best fit equations and correlation coefficient for flow rate vs. global solar irradiation.
Head (m) Best fit equation Correlation coefficient (R2) 50 Q = 259.426 + 0.0813 Hg 5.90 10 6 Hg2 0.94 60 Q = 208.465 + 0.0667 Hg 4.73 10 6 Hg2 0.99 70 Q = 75.448 + 0.0270 Hg 1.75 10 6 Hg2 0.95 80 Q = 120.620 + 0.041 Hg 2.75 10 6 Hg2
4000 Wh/m2/day 5000 Wh/m2/day 6000 Wh/m2/day 7000 Wh/m2/day
Daily flow rate (m3/day)
Head (m)
Fig. 5. Daily flow rate vs. head at various global solar irradiation data.
Table 2 Best fit equations and correlation coefficient for flow rate vs. head.
Global solar irradiation (Wh/m2/day)
Best fit equation Correlation coefficient (R2)
4000 Q = 42.941 0.689 H+ 0.0025 H2 0.99 5000 Q = 45.026 0.575 H + 0.0017 H2 0.98 6000 Q = 50.736 0.544 H + 0.0014 H2 0.99 7000 Q = 60.191 0.671 H + 0.0022 H2 0.99
Table 3 Influence of pumping heads on PVWPS performance.
Heads (m)
Maximum system efficiency (%) Average system efficiency (%) At low solar irradiation At high solar irradiation 50 7.00 6.12 3.26 60 6.50 6.25 3.44 70 6.10 6.30 3.79 80 5.61 6.60 4.41
The best system efficiency obtained (7 %) is given for the head of 50 m at low solar irradiation. At high solar irradiation, the best system efficiency (6.6 %) is obtained for the head of 80 m. The best average system efficiency (4.41 %) is obtained for the head of 80 m.
PV configuration 8S x 3P
Daily pump power (W)
Time (h)
Fig. 6. Daily pump power variation curve.
M. Benghanem et al./Energy Conversion and Management 77 (2014) 334–339 337
pumping head profile is the optimum. We have considered three state of PV pumping system:
First state: from the start pumping time until the time when the pump reached their maximum power (Fig. 5). Second state: Time corresponding to the maximum pump power which is practically constant during the day due to the advantage of using the SQF pump based on a microprocessor with MPPT (maximum power point tracking) [29]. Third state: Time corresponding to the decreasing power of the pump until the sun rise.
A Fig. 7b shows that at low solar radiation, the total system effi- ciency is too low for all pumping heads.
Figs. 7b-7d show the total system efficiency corresponding to the three considered states. At low solar radiation, the pump start pumping at low head (50 m) before the others heads (60 m, 70m and 80 m) as we can see in Fig. 7b . The total system efficiency is greater for the head of 50m than others heads. The low radiation is enough to pump at H =50m. Fig. 7c shows the effect of well pumping head profile on system performance. The head of 80m gives the high system efficiency than the others heads. So, 80 m head profile is considered as the optimal pumping head profile for the considered PV pumping sys- tem. This result is in good concordance with previous work [29] which we have state that the helical pump SQF2.5-2 is suitable for a deep well head. Fig. 7d shows that the total system efficiency is greater for the head of 50 m than others heads. This is due to the low solar radia- tion in the afternoon which the pump still pumping water for the head of 50 m.
7:05 8:45 10:25 12:05 13:45 15:25 17:05
Total system Efficiency (%)
Time (Hours)
80 m 70 m 60 m 50 m
Fig. 7a. Total system efficiency curves of four pump heads for the PV configuration (8S 3P).
Tolat system efficiency (%)
Time (hours)
80 m 70 m 60 m 50 m
5:50 6:15 6:40 7:05 7:30 7:55 8:20 8:45 9:10
Fig. 7b. Total system efficiency curves of four pump head in the morning (low solar irradiation).
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 Tolat system Efficiency (%)
Time (Hours)
80 m 70 m 60 m 50 m
8:45 10:25 12:05 13:45 15:25 17:05
Fig. 7c. Total system efficiency curves of four pump head during the day.
16:40 17:05 17:30 17:55 18:20
Total system Efficiency (%)
Time (Hours)
80 m 70 m 60 m 50 m
Fig. 7d. Total system efficiency curves of four pump head in the afternoon (low solar irradiation).
338 M. Benghanem et al./Energy Conversion and Management 77 (2014) 334–339
4. Analyses of main parameters affecting system performance
The main parameters affecting system performance are well head-flow rate characteristic, pump head-flow rate characteristic, solar radiation and PV power. Fig. 6 shows the daily pump power variation curve for the PV configuration (8S 3P). Fig. 7a shows the total systems efficiency for different experimental heads used. At the first observation from Fig.7a ,it is difficult to conclude which
5400 5600 5800 6000 6200 6400 6600 6800 7000
10 12 14 16 18 20 22 24 26 28 30 32
80 m 70 m 60 m 50 m
Daily Flow rate (m3/day)
Solar irradiation (Wh/m2/day)
Fig. 4. Daily flow rate vs. solar irradiation at various pumping heads.
Table 1 Best fit equations and correlation coefficient for flow rate vs. global solar irradiation.
Head (m) Best fit equation Correlation coefficient (R2) 50 Q = 259.426 + 0.0813 Hg 5.90 10 6 Hg2 0.94 60 Q = 208.465 + 0.0667 Hg 4.73 10 6 Hg2 0.99 70 Q = 75.448 + 0.0270 Hg 1.75 10 6 Hg2 0.95 80 Q = 120.620 + 0.041 Hg 2.75 10 6 Hg2
4000 Wh/m2/day 5000 Wh/m2/day 6000 Wh/m2/day 7000 Wh/m2/day
Daily flow rate (m3/day)
Head (m)
Fig. 5. Daily flow rate vs. head at various global solar irradiation data.
Table 2 Best fit equations and correlation coefficient for flow rate vs. head.
Global solar irradiation (Wh/m2/day)
Best fit equation Correlation coefficient (R2)
4000 Q = 42.941 0.689 H+ 0.0025 H2 0.99 5000 Q = 45.026 0.575 H + 0.0017 H2 0.98 6000 Q = 50.736 0.544 H + 0.0014 H2 0.99 7000 Q = 60.191 0.671 H + 0.0022 H2 0.99
Table 3 Influence of pumping heads on PVWPS performance.
Heads (m)
Maximum system efficiency (%) Average system efficiency (%) At low solar irradiation At high solar irradiation 50 7.00 6.12 3.26 60 6.50 6.25 3.44 70 6.10 6.30 3.79 80 5.61 6.60 4.41
The best system efficiency obtained (7 %) is given for the head of 50 m at low solar irradiation. At high solar irradiation, the best system efficiency (6.6 %) is obtained for the head of 80 m. The best average system efficiency (4.41 %) is obtained for the head of 80 m.
PV configuration 8S x 3P
Daily pump power (W)
Time (h)
Fig. 6. Daily pump power variation curve.
M. Benghanem et al./Energy Conversion and Management 77 (2014) 334–339 337
pumping head profile is the optimum. We have considered three state of PV pumping system:
First state: from the start pumping time until the time when the pump reached their maximum power (Fig. 5). Second state: Time corresponding to the maximum pump power which is practically constant during the day due to the advantage of using the SQF pump based on a microprocessor with MPPT (maximum power point tracking) [29]. Third state: Time corresponding to the decreasing power of the pump until the sun rise.
A Fig. 7b shows that at low solar radiation, the total system effi- ciency is too low for all pumping heads.
Figs. 7b-7d show the total system efficiency corresponding to the three considered states. At low solar radiation, the pump start pumping at low head (50 m) before the others heads (60 m, 70m and 80 m) as we can see in Fig. 7b . The total system efficiency is greater for the head of 50m than others heads. The low radiation is enough to pump at H =50m. Fig. 7c shows the effect of well pumping head profile on system performance. The head of 80m gives the high system efficiency than the others heads. So, 80 m head profile is considered as the optimal pumping head profile for the considered PV pumping sys- tem. This result is in good concordance with previous work [29] which we have state that the helical pump SQF2.5-2 is suitable for a deep well head. Fig. 7d shows that the total system efficiency is greater for the head of 50 m than others heads. This is due to the low solar radia- tion in the afternoon which the pump still pumping water for the head of 50 m.
7:05 8:45 10:25 12:05 13:45 15:25 17:05
Total system Efficiency (%)
Time (Hours)
80 m 70 m 60 m 50 m
Fig. 7a. Total system efficiency curves of four pump heads for the PV configuration (8S 3P).
Tolat system efficiency (%)
Time (hours)
80 m 70 m 60 m 50 m
5:50 6:15 6:40 7:05 7:30 7:55 8:20 8:45 9:10
Fig. 7b. Total system efficiency curves of four pump head in the morning (low solar irradiation).
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 Tolat system Efficiency (%)
Time (Hours)
80 m 70 m 60 m 50 m
8:45 10:25 12:05 13:45 15:25 17:05
Fig. 7c. Total system efficiency curves of four pump head during the day.
16:40 17:05 17:30 17:55 18:20
Total system Efficiency (%)
Time (Hours)
80 m 70 m 60 m 50 m
Fig. 7d. Total system efficiency curves of four pump head in the afternoon (low solar irradiation).
338 M. Benghanem et al./Energy Conversion and Management 77 (2014) 334–339
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