SOLARMETER 10.0 SOLAR IRRADIANCE

The Model 10.0 features an Integral Sensor and applications include solar irradiance measurements, solar panel (photovoltaic) system testing and estimation of PV array power.

 

 

Specifications Radiometer
Model 10.0
Irradiance Range 0-1999 W/m2
Peak Response 940 nm
Bandwidth 400-1100 nm
Resolution 1 W/m2
Conversion Rate 3.0 Readings/Sec
Display 3.5 Digit LCD
Operating Temps 0° C to 40° C
Operating Humidity 5% to 80% RH
Accuracy ±5% Ref WRR
Dimensions (LxWxD) 10.5 x 6 x 2.2 cm
Weight 110 Grams
Power Source 9-Volt DC Battery
Sensor Silicon Photodiode
Diffuser Virgin Teflon .005

 

To enquire on the the Model 10.0 please click on the link below or use the contact page.

When requesting a quote please provide quantity and suburb/state for postage/delivery details.

 

The Solarmeter model 10.0 brings 'point and read' simplicity to the measurement of solar irradiance. Just turn the meter on, point the sensor at the sun and obtain a reading in W/m2.

Sensor/Detector

Silicon Photodiode packaged in hermetically sealed glass window cap.

 Operation

Press and hold push-button switch on face of unit. Aim sensor window cap in top panel of meter directly at sun or perpendicular to panel array. Note reading on LCD and record value.

Battery operation voltage is 9V down to 6.5V. Below 6.5V the LCD numbers will begin to dim, indicating the need for battery replacement. Under "typical" service load, the battery should last about 2 years.


Proper Usage of Solarmeter® Radiometer for PV Array readings 

  • Wear UV protection eyewear or sunglasses when checking intense sunlight.

  • Aim sensor directly at sun to see maximum solar irradiance as a reference.

  • Aim sensor in same direction as PV panel to see irradiance striking array.

  • Re-orient PV panel direction if desired for best average position.

  • Maximum solar noon direction will of course vary throughout the year.

  • Do not subject the meter to extremes in temperature, humidity, shock or dust. Store meter away from humidity when not in use.

  • Use a dry, soft cloth to clean the instrument. Keep sensor free of oil, dirt, etc.

   

Meter Calibration

This instrument has been calibrated traceable to the World Radiometric Reference and is compliant with ANSI/NCSL Z540-1-1994. Model 10.0 Solarmeters are calibrated by transfer of "at sun" reading from master meter serial #00001. The master meter was calibrated to match standard class II pyranometer on a plane tilted 37° from horizontal, oriented perpendicular to the axis of the sun, under airmass 2 global solar irradiance at an independent test lab. A master meter calibration certificate is available on request.

Estimation of PV Array Power

Before beginning determine the following information from the manufacturer of the module array:

  • Effective active area for the PV cells in square meters _ _ _ m².

  • PV cells efficiency as percentage of input to output power _ _ _ %.

  • DC to AC conversion efficiency of the inverter in the array _ _ _ %.

Also, record the temperature near the back of the array _ _ _ °C


It is best to do this when sun is directly shining on module near noon. The meter error will increase (read low) at angles greater than about 35° from direct at-sun conditions.


Example Calculation with PV Meter reading 1000 W/m² perpendicular to 10 m² array at 10 m² active area, 14% cells efficiency, 95% converter efficiency, 40° C  

  • 1000 W/m² x 10 m² = 10000 Watts incoming sun power

  • 10000 W x 0.14 cell efficiency = 1400 Watts

  • 1400 W x 0.95 conversion efficiency = 1330 Watts

Typical temperature coefficient loss for PV cells is -0.5% per degree C over 25° or 7.5% for 40° as in this example (15° x 0.5% = 7.5% loss or 92.5% of above value. So:
  • 1330 W x 0.925 = 1230 Watts

Lastly, a small wiring & component loss of ~1% must be factored in.

  • 1230 W x 0.99 = 1218 Watts

 Energy Production over Time

The above 1218 Watts value is an "instantaneous" number. Energy is Watt (or kiloWatt) hours. So if the solar irradiance remained constant for an hour near noon, the energy produced would be 1218 WH.To estimate power over the entire day... take readings every hour and apply the above examples. Then add up each hour's value x number of hours for daily Watt/Hours.

Of course the value will increase toward summer, peaking near December 21 in the southern hemisphere... and decrease toward winter, lowest near the June 21 solstice. Northern hemisphere is opposite.   

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