PERFORMANCE MONITORING AND EVALUATION OF A 1.72 KW P GRID-CONNECTED PV SYSTEM

Transcription

1 PERFORMANCE MONITORING AND EVALUATION OF A 1.72 KW P GRID-CONNECTED PV SYSTEM Prepared by: L.M. Ayompe lacour.ayompe@dit.ie Project: Energy Policy Research in Domestic Dwellings Geographical site: FOCAS Institute building roof top, Dublin Institute of Technology, Kevin Street, Dublin 2, Ireland. Situation: Latitude 53.4 o N Longitude -6 o E Time zone GMT Installation date: 4 th April 2008 PV array orientation: Tilt 53 o Azimuth 0 o Near shadings: No shadings Building height: Approximately 12 m PV array capacity: 1.72 kw p s/array and inverter characteristics Table 1: /array specifications /array Specification Type Monocrystalline silicon Model Sanyo HIP-215NHE5 Capacity 215 W p Cell efficiency 19.3% Module efficiency 17.2% Maximum power (P max ) 215 W Maximum power voltage (V pm ) 42.0 V Maximum power current (I pm ) 5.13A Open circuit voltage (V oc ) 51.6 V Short circuit current (I sc ) 5.61 A Warranted minimum power (P min ) W Output power tolerance +10/-5 % Maximum system voltage (V dc ) 1000 Temperature coefficient of P max -0.3 %/ o C Module area 1.25m 2 No. of modules 8 NOCT 45 o C 1

2 Table 2: Sunny Boy 1700 inverter specifications Inverter Input Maximum dc power Maximum dc voltage PV voltage range at MPPT Output Maximum ac power 1700 W Nominal ac power 1550 W Efficiency Maximum efficiency 93.5% Specification 1850 W 400 V V Euro-eta 91.8% Weight 25 kg Fig. 1. PV system installation Monitoring and data acquisition The data acquisition system consisted of a Sunny Boy 1700 inverter, Sunny SensorBox and Sunny WebBox. The Sunny SensorBox was used to measure in-plane global solar radiation on the PV modules. Additional sensors for measuring ambient, wind speed and at the back of the were connected to the SensorBox. A solar radiation sensor with accuracy of ±8% and resolution of 1 W/m 2 installed on the PV module plane was used to measure incident solar radiation. The of the s was measured using a PT 100-M type sensor with accuracy of ±0.5 o C. Ambient air was measured using a JUMO PT 100 U type sensor with accuracy of ±0.5 o C. A Thies small wind transmitter anemometer with accuracy of ±5% was used to measure wind speed. The SensorBox and the inverter were connected to the Sunny WebBox via a serial RS485 link and a Power Injector. Data recorded at 5-minute intervals in the WebBox was extracted via a secure digital card and read directly into a computer. Fig. 2 shows the Sunny WebBox, power injector and an analog electricity meter. 2

3 Fig. 2. Sunny WebBox, power injector and analog electricity meter PV system energy production Year 1 (4 th April rd April 2009) Total production: 1514 kwhy -1 Normalised production: kwh/kw p y -1 Year 2 (4 th April rd April 2010) Total production: 1526 kwhy -1 Normalised production: kwh/kw p y -1 Results (April March 2010) Table 3: Measured solar insolation, long-term solar insolation, ambient air, PV module and wind speed Measured solar insolation (kwhm -2 d -1 ) Long-term solar insolation (kwhm -2 d -1 ) Ambient air Wind speed (ms -1 ) January February March April May June July August September October November December Average

4 Distribution Solar radiation (Wm -2 ) Fig. 3: Percentage distribution of solar radiation over the monitoring period Table 4: Normalised DC and AC energy output Month DC energy (kwh/kw p ) AC energy (kwh/kw p ) January February March April May June July August September October November December Average Total

5 Table 5: Array, final and reference yields of the PV system Month Array yield Final yield Reference yield January February March April May June July August September October November December Average Table 6:, PV system and inverter efficiency Efficiency Month PV system Inverter January February March April May June July August September October November December Average

6 Table 7: and system performance ratio and capacity factor Month PR PV system PR Capacity factor January February March April May June July August September October November December Average Seasonal performance Table 8: Seasonal average daily in-plane solar insolation, ambient, module, wind speed, efficiency, system efficiency and inverter efficiency over the monitored period. In-plane solar insolation (kwhm -2 d -1 ) Ambient Wind speed (m/s) efficiency System efficiency Inverter efficiency Season Winter Spring Summer Autumn Average Table 9: Seasonal energy generated, final yield, reference yield, array yield, capture losses, system losses, capacity factor and performance ratio over the monitored period. Season Energy generated (kwh/kw p ) Final yield (KWh/ kw p d -1 ) Reference yield (KWh/ kw p d -1 ) Array yield (KWh/ kw p d -1 ) Capture losses System losses Capacity factor performance ratio PV system performance ratio Winter * Spring Summer Autumn Average * value represents capture gain 6

7 Data file description Data files for each month are saved in separate folders. Data files are in comma separated value format (e.g cvs) and should be imported into blank worksheets in MS-Excel. Data would then be pasted into columns A-W. A description of the parameters recorded in each column is given in Table 10. Table 10: Description of measured parameters in data files Column heading Label Units Description A5 TimeStamp hh:mm Time B5 ExlSolIrr W/m^2 C5 IntSolIrr W/m^2 In-plane global solar radiation D5 OpTm h E5 TmpAmb C ー C Ambient air F5 TmpMdul C ー C G5 WindVel m/s m/s Wind speed H5 E-Total kwh Cumulative energy generated I5 Fac Hz Frequency J5 Fehler K5 h-on h L5 h-total h M5 Iac-Ist ma AC current from 1 st N5 Ipv ma DC current O5 Netz-Ein P5 Pac W AC power output Q5 Riso kohm R5 Seriennummer S5 Status T5 Uac V AC voltage U5 Upv-Ist V DC voltage from 1 st V5 Upv-Soll V W5 Zac Ohm 7