Irradiance and Temperature effect on Solar PV Performance

(1)

________________________________________________________________________________________________

Special Issue on International Journal on Advanced Electrical and Computer Engineering (IJAECE) Vol-3, Issue-1 ISSN(Online): 2349-9338, ISSN(Print): 2349-932X

For ONE-DAY National Conference On Restructuring in Indian Power Sector & Smart Grid‖

School of Electrical Engineering, KALINGA INSTITUTE OF INDUSTRIAL TECHNOLOGY, 7th April, 2016 118

Irradiance and Temperature effect on Solar PV Performance

1Arjyadhara Pradhan, ²S.M.Ali

1School of Electrical Engineering, KIIT University, Patia, Bhubaneshwar, Odisha, 751024

2Director Membership The Institute of Engineers, Kolkatta Email: ¹[email protected], ²[email protected]

Abstract : In the world energy scenario non renewable energy is the clean and pure form of energy where the source is mostly natural.. Solar energy is the mother of all energy resources and is available in clean and pure form.

Solar Irradiance and temperature are the two main factors affecting the performance of a PV module. With the increase in solar Irradiance maximum power increases but is not the case with that of increase in temperature. The temperature has an adverse effect. A marked reduction is seen in case of voltage where as current changes very slightly with temperature change. There are various methods used to improve the efficiency of the panel, like water cooling methods are employed to reduce the temperature of the panel. Other than that various other methods like dust cleaning, mppt tracking, effective selection of cell materials ,panel orientation are used for increasing the efficiency of solar module. This paper mostly shows how the solar irradiance and temperature affects the performance of the solar PV system.

Keywords: Insolation, Band gap, Photon, Tolerence.

I. INTRODUCTION

Solar PV modules are used for conversion of solar energy into electrical energy. But it is seen that all the solar energy are not effectively converted to electrical energy rather some of it is wasted in form of heat which cause heating of the panel. PV module's temperature rises high when it is exposed to long duration sun and mostly summer months. Keeping the irradiance constant if the cell temperature is increased, the cell current increases very slightly but cell voltage reduces remarkable. With increase in temperature band gap reduces which in turn causes increase in photon generation rate as well as rapid increase of reverse saturation current. Solar Insolation is the measure of the solar radiation falling on the earth’s surface. Thus with increase in insolation the photon generated current increases hence this causes both open circuit voltage and short circuit current to increase. But Temperature has an adverse effect .Therefore the solar panels gives better results at lower temperature then that at higher temperatures.

II. METHODOLOGY

An Experimental test was conducted on a bright sunny day at KIIT University Bhubaneshwar in the month of january 2016 .A 20 watt 12 volt rated Solar Module was considered for the testing purposed whose area was

calculated as 0.136 m².The Efficiency of the tested solar cell was calculated by applying the following relation:

η = (Vm×I_m)/ (I×S) ×100%...(1)

Where: V_m – maximum voltage [V], I_m -maximum current [A], I – intensity of radiation [W/m²], S – area of the cell [m²].Fill factor of current – voltage characteristic of solar cells can be calculated by using the following relation:

FF = V_m·I_m/V_oc·I_sc ……. (2)

Where:V_oc– open circuit voltage [V],Isc – short circuit current [A].

Fillfactor is the measure of the quality of the cell.An ideal cell has fill factor unity. It can be maximized by minimizing internal series resistance and maximizing shunt resistance.

Fig 1 Shows the Experimental set up of the PV module.

In the experimental set up shown voltmeter is used for measuring voltage, ammeter for measuring current, rheostat for varying the resistance, RTD for measuring the temperature and solar meter is used for measuring the solar irradiance and there are connecting wires which are used to connect all the instruments. The following readings are taken at a regular interval of 1 hour from morning 10 am to 4 pm.

Table 1: Shows the Irradiance and temperature taken at various intervals.

Sl.

No.

Time Irradiance (watt/m²)

Temperature (^oc)

1 10:00-11:00 677 47

2 11:00-12:00 714 49

3 12:00-1:00 738 51

(2)

________________________________________________________________________________________________

4 1:00-2:00 706 49

5 2:00-3:00 442 45

6 3:00-4:00 354 42

Power drop off is calculated by using the formula P_{drop off} = Output Tolerance / P_max

Table 2 : Shows the value of Power drop off Sl.

No.

Time P_max

(watt)

P_drop off 1 10:00-11:00am 14 0.00214 2 11:00-12:00pm 14.7 0.00204 3 12:00-1:00pm 14.88 0.00201 4 1:00-2:00pm 13.5 0.00222 5 2:00-3:00pm 9.7 0.00309 6 3:00-4:00pm 6.4 0.00468

Fig 2 : Shows how the maximum power increases with increase in Irradiance.

Maximum power increases with increase in solar Insolation .It has a positive effect. Panels more exposed to sunlight produces more power than that for shading condition.

P_temp = P_o/p[1- P_{drop off}(T_cell – 25⁰c)]

Where Ptemp is the power loss due to temperature effect.

T_cell represents cell operating temperature.

Powerdroff is the power calculated taking output tolerance as +3% in table no 2.

Power output is the power of the system without taking temperature effect into account. The values calculated are tabulated as below.

Table 3: Shows values of P_temp at different temperature Sl

No

Time Po/p Pdrop off Temperat

ure (⁰c) Ptemp

1 10:00-11:00 9.492 0.00214 47 9.064

2 11:00-12:00 10.481 0.00204 49 9.990

3 12:00-1:00 10.936 0.00201 51 10.387

4 1:00-2:00 9.504 0.00222 49 8.996

5 2:00-3:00 4.268 0.00309 45 3.993

6 3:00-4:00 2.2528 0.00468 42 2.064

Effectiveness = P_temp /P_max

Fig 3: Shows the Effectiveness of the system Table 4: Show the values of solar Module efficiency at different temperature.

Sl No

Time Temperature

(⁰c)

Efficiency (%)

1 10:00-11:00 47 15.18

2 11:00-12:00 49 15.15

3 12:00-1:00 51 14.8

4 1:00-2:00 49 14.1

5 2:00-3:00 45 13.8

6 3:00-4:00 42 13.3

Fig 5: Shows efficiency decreases with increase in temperature.

III. CONCLUSION

From the above study it is found that solar panel maximum voltage and maximum current increases with increase in solar irradiance .But with Increase in module temperature efficiency decreases, Even the power loss due to temperature effect is less than that of the total output power. It is also found that the system is more effective at around 12pm to 1pm.Maximum power increases with increase in Solar Insolation. Various methods like cooling, dust cleaning, mppt tracking, effective panel orientation can be used to enhance the system performance .mostly water cooling methods can be used to can be used to reduce the temperature.

ACKNOWLEDGEMENT

I would like to thank School of Electrical Engineering, KIIT University Bhubaneswar, Odisha for providing me a platform to conduct the test.

REFERENCES

[1] Griffith JS, Rathod NS, Paslaski J. Some tests of flat plate photovoltaic module cell temperatures in simulated field conditions. Proc. 15th IEEE Photovoltaic Specialists Conf., Kissimmee, FL, 1981; p.822-30.

(3)

________________________________________________________________________________________________

[2] Y. Tripanagnostopoulos, Nousia Th, M.

Souliotis, P. Yianoulis Hybrid photovoltaic/thermal solar systems Solar Energy, 72 (3) (2002), pp. 217–234

[3] Affolter P, Haller A, Ruoss D, Toggweiler P. A new generation of hybrid solar collectors—

Absorption and high temperature behaviour evaluation of amorphous modules. Proc. 16th European Photovoltaic Solar Energy C omf., Glasgow, UK; 2000.

[4] Platz R, Fischer D, Zufferey MA, Anna Selvan JA, Haller A, Shah A. Hybrid collectors using thin-film technology. Proc. 26th Photovoltaic Specialists Conf. Anaheim, CA, 1997.

[5] Adamo, F.; Attivissimo, F.; Di Nisio, A.;

Spadavecchia, M., "Characterization and Testing of a Tool for Photovoltaic Panel Modeling,"

IEEE Transactions on Instrumentation and Measurement, vol.60, no.5, pp.1613-1622, May 201

[6] Jeevandoss, C.R.; Kumaravel, M.; Kumar, V.J.;

"A Novel Measurement Method to Determine the C–V Characteristic of a Solar Photovoltaic Cell,"

IEEE Transactions on Instrumentation and Measurement , vol.60, no.5, pp.1761-1767, May 2011.

[7] Loredana Cristaldi, Marco Faifer, Marco Rossi and Ferdinanda Ponci, ―A Simple Photovoltaic Panel Model: Characterization Procedure and

Evaluation of the Role of Environmental Measurements‖, IEEE Transactions on Instrumentation and Measurement.

[8] M. Catelani, L. Ciani, L. Cristaldi, M. Faifer, M.

Lazzaroni, P. Rinaldi, ―FMECA Technique on Photovoltaic Module‖, Proc. Of IEEE - International Instrumentation And Measurement Technology Conference (I2MTC) – Binjiang, Hangzhou, China – May 2011, pp. 1717-1722.

[9] M. Lazzaroni, L. Cristaldi, L. Peretto, P. Rinaldi and M. Catelani, Reliability Engineering: Basic Concepts and Applications in ICT, Springer, ISBN 978-3-642-20982-6, e-ISBN 978-3-642- 20983-3, DOI: 10.1007/978-3-642-20983-3, 2011 Springer-Verlag, Berlin Heidelberg.

[10] Meyer, E.L.; van Dyk, E.E.; ―Assessing the reliability and degradation of photovoltaic module performance parameters‖ IEEE Transactions on Reliability , vol.53, no.1, pp. 83- 92, March 2004.

[11] P.R. Mishra, J.C. Joshi, ―Reliability estimation for components of photovoltaic systems‖, Energy Conversion and Management, Volume 37, Issue 9, September 1996, Pages 1371-1382.

[12] Powers, L.; Newmiller, J; Townsend, T.;

"Measuring and modeling the effect of snow on photovoltaic system performance," Photovoltaic Specialists Conference (PVSC), 2010 35th IEEE,

pp.973-978, 20-25 June 2010.

