PERFORMANCE EVALUATION OF SOLAR ENERGY DEVICES BY USING A DATA LOGGING SYSTEM

Transcription

1 PERFORMANCE EVALUATION OF SOLAR ENERGY DEVICES BY USING A DATA LOGGING SYSTEM Vijay Singh and Mohd. Murtaja Department of Electronics and Instrumentation Engineering Ch. Charan Singh University Campus, Meerut (UP) murtaza_amu@yahoo.com, kkrr.vijay@gmail.com Abstract-The present work demonstrates the setting up of a reliable and efficient data acquisition system, which works automatically on a 24 hours basis and logs the data in defined format, for its long time use. The seven weather parameters have been specified to be evaluated and terms of their impact on performance of solar energy systems. A comprehensive data acquisition system has been installed, using the respective sensors for each of the above monitored weather parameters viz. Pyranometer, Pyranometer with shading ring, Anemometer, Wind Vane, Visalia s weather Transmitter (for the measurement of ambient temperature and relative humidity). Further the data of direct solar radiation has been used for the thermal performance evaluation of parabolic concentrating solar cooker and it has being also found to provide reasonably good result for a given concentrating solar cooker. Therefore it can be concluded that the weather data monitored from the present setup can be very easily used for the performance evaluation of any solar energy device. 1. INTRODUCTION Energy in various forms played an increasingly important role in worldwide progress and industrialization. In more recent years, use of solar energy in various fields is being through direct conversion to electricity or, in thermal energy at various temperatures. Solar energy provides unlimited supply of energy, it is environmental friendly, widely distributed and of no cost. In India, the annual average global radiation is about 5kWh/m 2 per day with about sunshine hours per year. Estimation of solar radiation as resources with other weather parameters is of immense importance for the performance evaluation of solar energy devices[4]. This data is a prerequisite for the design of any solar energy system to be installed at any place. The proposed work related to measurement solar radiation as a resource along with weather parameter relevant for the evaluation of performance of thermal and SPV (Solar Photo Voltaic) devices. Data logger or data acquisition system is used to measure these parameters.the data is recorded with the help of this instrument continuously and store for analysis. II. SENSOR USED TO MEASURE FOR EACH WEATHER PARAMETER The following sensors are used to measure whether parameters Pyranometer: - This instrument is used for the measurement of global total radiation received from the entire hemisphere, when it is fitted with the shading ring. It measures the diffuse radiation. [1] RTD and Thermocouple: - It is used for the measuring of ambient Temperature. Vaisala s Whether Transmitter WXT510:-This sensor is used for measuring the wind velocity. Wind Direction:- vane is used for measuring of wind direction III. INSTALLATION AND MONITORING METHODOLOGY The test performance monitoring of the weather parameters is aimed of this work. The following methodology is followed for the monitoring of the weather parameters for their application in performance evaluation of solar energy devices. 1. The data is sensed at every 10 second, and averaged. These timing can be changed, if necessary. 2. The data from data CR 10X data logger is store in the storage module, which is

2 further downloaded onto PC regularly to generate the performance report. 3. A close monitoring of system performance required till the system is stabilized for this purpose : a weekly report consisting of the weather data, various system parameters, load pattern etc, is generated Using standard package, the data is analyzed and observations are recorded. Further monthly reports give more details performance idea. This can also be compared with the stimulated data on a monthly and annual basis. A systemic database for the further reference is created. System shut down time for maintenance, cleaning of module etc. shall be recorded separately. These values have to be incorporated in the performance analysis. The schematics diagram of measurement setup is shown in Fig.1 an hour and plotted as shown in fig. 3. Program for monitoring of the weather parameters is used with the help of CR10 data logger using PC208 support software. Pyranometer Pyranometer with Shading Ring Vaisalla s Weather Trans. Anemometer & Wind Vane CR 10 Data Logger Computer Printer Fig. 2 Flow chart of Weather Monitoring Program. Fig.1 Schematics Diagram of Measuring Setup Photograph of weather station are shown in fig.4 and measurement setup for weather station is shown in fig. 5. IV. Data Logger software Since it was required to study the performance of solar thermal device, the number of parameters to be monitored on continuous basis and hence to easy this task, a detailed program is developed using PC208W software and flow chart of the program is shown in fig. 2.[8]. V. RESULT The performance of solar thermal (ST) and a Photo Voltaic (SPV) system under a typical day has also been estimated, using the recorded radiation data. The meteorological parameters for a period of July month of year 2007 are recorded every half Fig. 3 Various Weather Parameter Curve, Date 1-July, Analysis of the result

3 The result of the analysis of the three parameters viz. solar radiation data, horizontal global, normal incidence beam radiation and diffuse radiation are summarized as Total of global solar radiation for the whole day from 6:30 A.M. to 5:30 P.M. =5190 wh/m 2 = 5.19 kwh/m 2 Total of direct solar radiation for the whole day from 6:30 A.M. to 5:30 P.M. = 4453 wh/m 2 =4.453 Kwh/m 2 Total of Diffuse solar radiation for the whole day from 6:30 to 5:30 P.M. =1640 wh/m 2 =1.64 kwh/m 2 A. Performance analysis of solar water heating system Since the solar water heating system is normally incidents at latitude angle, the radiation for global horizontal (I GH ) it is possible to entitle the global latitude is i\ I GH = I GL (CosǾ) Useful global radiation = 5.19 kwh/m 2 Temperature of water/ambient = 20 o C (assumed) Area of solar flat plate collector = 2 m 2 (given) Total energy = = kwh Total energy in K calories = ( )/4.2 = Kc Available energy = Total energy figure of merit = = Kc For 100 liter LPD system Mass of 100 liter= 100Kg Temperature of water (t 1 ) = 20 Specific heat of water =1 Water temperature t 2 =? Available energy = m s (t 2 -t 1 ) = (t 2-20) T 2 = C So the value of temperature (t 2 ) indicates a good quality of solar water heating system. B. Performance Analysis of Dish type solar cook Area =π D 2 /4= π/4 (1.4) 2 = m 2 Reflective of solar dish= 0.95 Absorption of solar dish=0.9 Total figure of merit of solar disc = = F= Total generated energy = Area F I d = =6.01 kwh Load in pot = 5 Kg Total generated energy in K Calorie = ( )/4.2 = Kc Temperature of water t 1 = 20 o c (assume) T 2 =? Available energy = m S (t 2 -t 1 ) = 5 (t 2-20) t 2 = = C This temperature of water (t 2 ) is very close for standard dish type solar cooker. C. Performance analysis of solar street light system (SLS) Wattage of SPV module = 75 W Load on SPV module = 11 W CFL Battery Voltage = 12 V Useful Global Radiation = 5.19 Kwh/m 2 Global radition at latitude angle I GH =I GL coǿs Where Ǿ = latitude angle =40 0 I GL = I GH / cos 40 = 5.19 sec 40 0 = = 6.77 Kwh/m 2 Generated Energy by 75 W PV module = = 508 Wh Generated AH = 508/16..4= 31 AH Assuming loss factor due to charge controller and battery efficiency = Available A.H= generated AH (Loss factor of Battery Inverter) = 31 ( ) =25.03 A= G AH (1) Voltage of the CFL= 11W The DC power requirement assuming the inverter efficiency =85%= 0.85 A 11 W CFL is required amp= 11/0.85 = W (D.C) Energy required for 12 hours = * 12 = W Now required AMP = /12 V = AH Now AH is being needed by SPV module for 12 hours = AH = N AH (2) Three conditions are applied here 1. N AH > G AH, this is bed situation and battery get discharged 2. N AH = G AH (status of Change) both are remains the same 3. N AH < G AH, then Battery get discharged Where NAH is needed AH, GAH is generated AH from equation (1) and (2)

4 Now third condition is applying here because the generation of AH is higher than consumed AH so this SPV module is very good in accuracy VI. CONCLUSION The value of the daily solar radiation has been used to predict the thermal performance of the solar water heating system for these days. It has been observed that they predict performance and the measured data at the pre-location give a fairly reasonable assessment of the performance (SWHS) The data has also been analyzed for predicting and evaluation the performance of solar street Lightening system (SLS) at the experimental location i.e. SEC. The data has been found validating the performance of the system even during the worst month of the year. Further the data the direct normal radiation has been used for the thermal performance evaluation of the parabolic concentrated solar cooker. It is found to provide reasonable sound estimate of the result for the given concentrating solar cooker Fig. 4 Data logger, Connection of data logger, Installed radiation sensors and Weather Station VII. FUTURE WORK By use of high speed, high capacity data loggers it is possible to generate data with lesser time interval and the accuracy of the measured parameter can be improved significantly. By adding more number of such weather stations at number of location across the country can produce the weather data with great resolution which lead to an accurate mapping of the data. In this connection it should be monitor that use of satellite based techniques the data will improve the resolution to a larger level. Such data on the GIS (Global Position system) platform enable accurate mapping and further development of solar energy utilization in the country. REFERENCES [1] A.Mani, Hand book of Solar Radiation Data for India, Allied Publishers Pvt.Ltd. pp-7. [2] A.I.Kudish and A. Lanetz, Analysis of Solar Radition Data for Beer Sheva, Israel andits Environs, Solar energy Volume 48,pp97-106, Fig. 5 Measurement set up installed for Weather Station [3] Anokh singh, Principal of Communication Engineering by S.Chand & Compony Ltd Edition 2000, New Delhi pp [4] Duffe John A., Solar Engineering of Theram Process,a wiley-interscience Publication, John Wiley & sons Inc,pp1-10.

5 [5] EPPLEY Laboratory, inc., Scientfic Instruments for the precision Measurement since [6] Essam E.I. Hinnawi & Asi T.K. Bisvas, Renewable Sources of Energy and the Enviroment, published by TYcooly International Publishing Ltd, First edition 1981,pp [7] J. J. MINHALSKY Comparison of a national weather service s foster Sunshine Recorder and the world metrological organization standard for Sunshine During, Solar Energy vol. 48, No-02 pp [8] Campbell Scientific Instrument Manual of CR data Logger, USA. [9] Tiwari G.N. Solar Energy Fundamentals, Design, Modeling and Applications, Narosa Publication House, Second Edition 2005, new delhi , 1-50.