1. An experimental analysis of specially
designed PV absorber surface on
performance of hybrid solar system
Name : V N Palaskar, Research Scholar (User Account no: 1068)
ICT Mumbai.
Dr. S.P. Deshmukh, Research Supervisor, ICT
Paper code: 48.
Mumbai.

2. Quick glance of presentation:
1) Introduction
2) Experimental
3) Equations used to calculate various parameters
4) Results and Discussion
5) Conclusion
6) Future scope

3. 1) Introduction
A. Voltage generated by commercial PV module was found decreasing by
0.065 to 0.085 V/ 0C rise in its temperature above 25 0C at ATC
conditions.
B. Due to its heating, electrical efficiency of module drops by 10 % to 35% .
C. At 25 0C module can produce 10% to 35% more power than un cooled
module.
D. PV modules convert only 15% of solar energy to electrical energy and
85% energy dissipates to surrounding in the form of heat, increasing
temperature of module and surrounding air.
E. Hybrid PV/T solar systems combine PV module and solar thermal
collector, forming equipment that produces electricity and thermal
energy from one integrated system .
F. A specially designed heat exchanger called an oscillatory flow PV
absorber and its effect on performance of hybrid PV/T system is studied
in this work.

4. 2) Experimental
2.1) Special flow Aluminum PV absorber heat exchanger
surface design with fabrication.
2.2) Fiber Glass wool insulation.
2.3) Complete assembly of hybrid PV/T solar water
system with all measuring instruments.
2.4) Experimental observations.

5. 2.1 ) Heat exchanger surface design with fabrication
mounted at back side of PV module.
Fig. 1 Installation of an oscillatory flow PV absorber
surface at rear side of PV module.

6. 2.2) Fiber Glass wool insulation fitted at back side of
heat exchanger.
Fig. 2 Setting up glass wool at rear side of an oscillatory
flow PV absorber surface.

7. 2.3) Complete assembly of hybrid PV/T solar water
system with all measuring instruments.
Fig. 3 Hybrid (PV/T) solar water system which shows all Measuring instruments
connected each other to form assembly.

8. 2.4) Experimental observations
A) All experiments were conducted during month of May-13 and
slope of PV module was kept at 50 (North- South).
B) Daily experiments performed between morning 9:30 to 4:30
pm.
C) Different readings such as global radiation; wind velocity of
surrounding air; voltage and current at corresponding
loading conditions were recorded in 30 minutes of time
interval over a day.
D) K-type thermocouples were attached to data logger to scan
and record temperatures of PV module at various points of
its top & bottom and ambient temperature in 30 second time
interval were recorded.

9. E) Inlet and exit water temperatures from hybrid system were
recorded to calculate thermal power for every 30 minutes of
time interval.
F) Experiments on hybrid system were conducted by
considering different flow rates of water through heat
exchanger such as 0.028, 0.035 and 0.042 kg/sec to predict
the flow rate of system generating highest PV, thermal,
combined PV/T efficiency and performance ratio.

10. 3) Equations used to calculate various
technical parameters.
PPV = V * I
(1)
PT = m * Cp * (Twe –Twi )
(2)
IG = IGn * APV
(3)
PR= PPV/PSTC
(4)
ɳPV = (V * I)/ IG
(5)
ɳT = PT / IG
(6)
ɳPV/T = ɳPV + ɳT
(7)

11. 4) Nomenclature and Greek symbols.
V
:
Voltage produced by PV module at ATC conditions (V)
I
:
Current produced by PV module at ATC conditions (A)
PPV
:
Electrical power produced by PV module at ATC conditions (W)
PT
:
Useful thermal power produced by hybrid (PV/T) solar water system (W)
m
:
Mass flow rate of water (kg/sec)
Cp
:
Specific heat of water (J/kg 0K)
Twi
:
Water inlet temperature (0K)
Twe
:
Water exit temperature (0K)
IG
:
Total solar input power incident on PV module (W)
IGn
:
Total Solar radiation measured by Pyranometer parallel to module
surface (W/m2)
APV
:
Area of PV module (m2)
PR
:
Performance ratio (%)
PSTC
:
Electrical power produced by PV module at STC conditions (W)
ηPV
:
Electrical Efficiency of PV module (%)
ɳT
:
Thermal efficiency of hybrid (PV/T) solar water system (%)
ɳPV/T
:
Combined PV/T efficiency (%)

12. 5) Result and Discussion
5.1) Performance of un-cooled commercial PV module:
A. The highest voltage and current produced by un-cooled
module were 27.5 volts and 4.2 A at 12.30 pm as shown in
fig. 4 & 5.
B. At the same time, module was able to produce highest
PV electrical power of 115.2 W with performance ratio of
64 % and PV module efficiency of 10.2% as shown in fig.
6 & 7.
C. During experiments, un-cooled PV module was found
heated at top side with 64 0C temperature as shown in
fig.8.

13. 5.2) Performance of hybrid PV/T solar water system:
A.
After cooling, open circuit voltage and working voltage were
found to be 39.80 V and 30.3 V at 1 pm.
B.
As a result of cooling , PV power was found increased to
134.2 W with performance ratio of 75 % and PV efficiency of
11.7 % respectively at the same time as shown in fig. 6 & 7.
C.
Due to cooling of module, additional thermal power of 482 W
was obtained from hybrid system at flow rate of 0.035 Kg/sec
producing highest PV power.
D. By fixing heat exchanger at back side of PV module and
utilizing waste heat energy, module working temperature was
dropped to 46.7 0C over a day as shown in fig. 8.
E.
The combined PV/T efficiency 53.7 % was obtained from
hybrid system as shown in fig. 9.

14. Voltage (V)
36
32
28
24
20
16
12
8
4
0
Vuncooled
Vcooled
09:00 09:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00
Time (Hrs)
Current (A)
Fig. 4 Voltage produced by un cooled and cooled PV module.
5.50
5.00
4.50
4.00
3.50
3.00
2.50
2.00
1.50
1.00
0.50
0.00
Iuncooled
Icooled
09:00 09:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00
Time (Hrs)
Fig. 5 Current produced by un cooled and cooled PV module.

15. Photovoltaic output Power (W)
180.0
160.0
140.0
120.0
100.0
80.0
60.0
40.0
20.0
Ppv-uncooled
Ppv-cooled
0.0
09:00 09:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00
Time (Hrs)
Fig. 6 PV power produced by un cooled and cooled PV module.
16.0
PV module efficiency (%)
14.0
12.0
10.0
8.0
6.0
ηPV-un cooled
4.0
ηPV-cooled
2.0
0.0
09:00 09:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00
Time (Hrs)
Fig. 7 PV efficiency of un cooled and cooled PV module.

16. Top side PV Module temperature (0C)
70.0
60.0
50.0
40.0
30.0
TTPV-uncooled
20.0
TTPV-cooled
10.0
0.0
09:00
09:30
10:00
10:30
11:00
11:30
12:00
12:30
13:00
13:30
14:00
14:30
15:00
15:30
16:00
16:30
17:00
Time (Hrs)
Fig. 8 Top side temperature (TTPV) attended by un cooled and cooled PV module.
70.0
ηPV-un cooled
Efficiency (%)
60.0
ηPVT
50.0
40.0
30.0
20.0
10.0
0.0
09:00 09:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00
Time (Hrs)
Fig. 9 PV efficiency of un cooled and combined PV/T efficiency of cooled PV module.

17. 5.3) Performance comparison of simple PV module and
hybrid PV/T system at ATC condition:
Sr. Technical parameters
No
Simple
Hybrid PV/T
PV module
system
1
Voltage (V)
27.5
30.30
2
Current (A)
4.2
4.43
3
PV power (W)
115.2
134.2
4
PV efficiency (%)
10.2
11.7
5
Thermal power (W)
----
482
6
Thermal efficiency (%)
----
42
7
Combined PV/T efficiency (%)
----
53.7
8
Top side module temp. (0C)
64
46.7
9
Performance ratio
64
75

18. 6) Conclusions
A) After converting
simple PV module to hybrid PV/T
system, PV electrical power and efficiency of water
cooled module had been improved by 16.5 % and 14.7 %
respectively at 1 pm.
B) Hybrid PV/T system produced thermal power and
efficiency of 482 W and 42% respectively achieving
combined efficiency of 53.7 %.
C) After cooling, module temperature had been decreased
by 37 % at water flow rate of 0.035 kg/sec.

19. D) The performance ratio of PV module of hybrid PV/T
system was increased by 11% because of cooling effect.
E) On yearly basis this hybrid system can produce combined
PV/T energy of 1110 KWh with PV electrical energy of
345 KWh for PV module area of 1.25 m2.

20. Thank you !