The effect of reflection from snow on the output of solar panels based on six years of observations

Transcription

1 The effect of reflection from snow on the output of solar panels based on six years of observations Juha A. Karhu 1, Anders Lindfors 1, Sami Rantamäki 2 1 Finnish Meteorological Institute (FMI), ( JuhaA.Karhu@fmi.fi) 2 Satakunta University of Applied Sciences (SAMK)

2 Snow can both suppress and enhance PV production

3 Snow can both suppress and enhance PV production

4 Snow can both suppress and enhance PV production

5 Snow can both suppress and enhance PV production

6 Snow is usually treated as a burden Picture by Rimstar.org,

7 Actual situation can be complex

8 Research plan I. Observations on the effect of snow on photovoltaic (PV) production will be collected. II. Using the observations and radiative transfer modeling, a parameterization which takes into account the effect of snow will be developed and applied to a PV model. III. The PV model with parameterized snow effect will be used to predict the PV production at the time scale of numerical forecasts and IV. to study how the PV potential in Finland and in other regions with a seasonal snow climate will change in the future under different climate scenarios

9 Observations - Over 500 solar power stations covering the geographical area of Finland - Citizens involved - FMI weather observation network of c. 400 stations - 10 sites with well-defined and monitored environmental conditions (weather, irradiance, albedo, amount and properties of snow) - In this presentation observations from one site, SAMK-Pori, with three independent panel rows is used

10 PV observations from SAMK-Pori SAMK-Pori PV system consisting of three equal series with 1260 W peak each. The panels of the three series have different tilt angles of 30, 45 and 60. (Photo by SAMK)

11 PV observations from SAMK-Pori Aerial view of the SAMK campus with the PV system on the roof. The azimuth angle of the series is 159 (south-east). (Photo by Google)

12 Weather observations at Pori Pori railway station (FMISID: , LPNN: 1021, WMO: 02926) ~1,6 km to SAMK-Pori

13 Results 1/2 Average difference (%) in solar power at SAMK- Pori under clear sky conditions during springs panel inclination ( ) snow versus no snow, n = 132* 5,02 7,43 9,56 same snow conditions, n= 63** 5,69 6,50 7,36 - during four hours of midday (8 12 UTC) - *std and ste to be calculated, nevertheless observation are not independent - rms-difference to be calculated, Bootstrap method to be applied - work in progress

14 Results 1/2 Average difference (%) in solar power at SAMK- Pori under clear sky conditions during springs panel inclination ( ) snow versus no snow, n = 132* 5,02 7,43 9,56 same snow conditions, n= 63** 5,69 6,50 7,36 - during four hours of midday (8 12 UTC) - *std and ste to be calculated, nevertheless observation are not independent - rms-difference to be calculated, Bootstrap method to be applied - work in progress

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16 Clear sky PV-output under different snow conditions

17 Clear sky PV-output under different snow conditions

18 Snow depth during March in Pori

19 Results 2/2 Solar power production of SAMK-Pori panels with 30, 45, and 60 degree inclinations in March (kwh) panel inclination ( ) Year

20 Future work - Irradiance: clouds, aerosols, ozone, water vapor, snow properties - Panel efficiency: temperature, wind, cleaning, soiling, maintenance breaks, wearing and aging of the panels - testing statistical signifigance - measurement errors and coding errors - Handling the data from extensive and diverse network of PV-stations

21 ARCSUN Sodankylä, Finland Solar power and radiation measurement site ARCSUN at the FMI Arctic Research Centre, Sodankylä. On left is the view as seen from the panels and pyranometer. On right, the panels (inclinations of 20 and 90 ) and pyranometer with vertical (90 ) mount can be seen. Temperature is measured from air and the back sides of both panels. (Photos by Juha A. Karhu)

22 ARCSUN Sodankylä, Finland Location: N E Panel: Sunmodule Plus SW 260 POLY, STC 260 Wp Inclination: 90 Orientation: 115 Max power on W