The Solar Outdoors Open Test Field

The Open Solar Outdoors Test Field (OSOTF) is an open source , highly efficient, and well-coordinated method of monitoring solar photovoltaic modules.


As the solar photovoltaic industry grows there is an increased demand for high-quality research in solar systems design and optimization in realistic (and sometimes extreme). [1] To answer this need, a partnership HAS FORMED the Open Solar Outdoors Test Field (OSOTF). The OSOTF Was Originally Developed with a strong partnership entre les Queen’s Applied Sustainability Research Group run by Joshua M. Pearce at Queen’s University (now at Michigan Tech ) and the Sustainable Energy Applied Research Center(SEARC) at St. Lawrence College headed by Adegboyega Babasola. This collaboration has grown rapidly to include multiple industry partners and the OSOTF has been redesigned to provide critical data and research for the team.

The OSOTF is a fully grid-connected test system, which continuously monitors the output of photovoltaic modules and correlates their performance with a long list of highly accurate meteorological readings. The teamwork has resulted in one of the largest systems in the world, and can provide valuable information on the actual performance of photovoltaic modules in real-world conditions. Unlike many other projects, the OSOTF is organized under open source principles.

All data and analysis will be made freely available to the entire public and photovoltaic community. [2]

The first project for the OSOTF quantifies the losses due to a snowfall of a solar photovoltaic system, generalizes these losses to any renting. [1] [3] This work was done by creating empirical data from the OSOTF. [4] [5] This application of the OSOTF has been extensively covered in the media. [6]


This system has been made possible by the Natural Sciences and Engineering Research Council of Canada and contributions from:

  • Advanced Solar Investments Ltd.
  • AYA Instruments
  • Calama Consulting
  • Dupont Canada
  • eIQ Energy
  • Heliene Inc.
  • KACO New Energy Inc.
  • nanofilm
  • Michigan Technological University
  • Photovoltaic Performance Labs Inc.
  • Schueco Canada
  • Silfab Ontario
  • Soventix Canada Inc.
  • Sustainable Energy Research Center at St. Lawrence College
  • Sustainable Energy Technologies Ltd.
  • Queen’s Applied Sustainability Group
  • Universidad Privada Boliviana
  • Uni-Solar Ovonic LLC

The development of this test facility is a testament to the commitment of the photovoltaic industry to continuous innovation, and the researchers hope that it will be a valuable tool for the development of a sustainable power system worldwide. [7]

Open Solar Outdoors Field Test

The SEARC Open Solar Outdoors Test Field consists of two discreet test beds, the largest of which is located on the roof of the new Wind Turbine and Trades Building at St.Lawrence College and which has room for 60 commercial PV panels, which are divided between eight angles of 5.10,15,20,30,40,50 and 60 degrees. Live video for the test field is openly available online . Full data access available here .

The second test field is located on a flat rooftop at St.Lawrence College and consists of two flat roof ballasted systems. Live video of this test is also available online

In addition to the Queen’s Innovation Park Test Site which was developed as part of a preliminary study on the effects of photovoltaic performance by Sustainable Energy Technologies. It consists of 16 panels mounted at angles from 0 to 70 degrees, with two each increments of 10 degrees. By monitoring panel output, solar influx, snow fall and meteorological factors can be determined for a general system at a variety of angles. In addition, thermal panel measurements lead to a better understanding of snow shedding mechanisms. A series of analysis algorithms has been developed which allows for the production of data, the performance ratio, and the estimated losses / gains due to snowfall. A detailed description of the sensors and measurements used in the study can be seen below.


The Open Solar Outdoors Test Field is designed to be one of the first-of-a-kind test facilities that makes this site one of the first PV test beds in North America.The capabilities of this test bed are shown in the following table.

Measurement Device Description Accuracy
Solar Radiation-Direct CMP-22 Pyranometer The highest quality secondary standard device, calibration directly in the World Radiometric Reference in Davos, Switzerland <1%
Solar Radiation-Diffuse CMP-22 Pyranometer The highest quality secondary standard device, directly calibrated to the World Radiometer Reference in Davos, Switzerland, fitted with an adjustable shadow band <1%
Solar Radiation-Albedo CMP-11 Pyranometer Secondary standard device, directly traceable calibration to the World Radiometer Reference in Davos, Switzerland. <2%
Wind Speed ​​and direction RM-young wind monitor WMO standard integrated wind speed and direction sensor. +/- 3 m / s+/- 3 °
Temperature / RH Rotronic HygroClip Integrated temperature / RH sensor with radiation shield. HR: +/- 1.5%Temp: +/- 0.2 C
Snow Depth SR50 ultrasonic snow depth sensor Provides accurate readings of snow on ground using calibrated ultrasonic pulses. Can give total snow depth and accumulation / settling rate. +/- 0.4%
Data Acquisition System Campbell Scientific CR1000 The standard industry for high-accuracy environmental monitoring. Expanded with multiplexers to accept 106+ point measurements +/- 0.12%
Photographs StarDot NetCam IP camera High resolution camera, photographing array at 5 minute intervals. Pictures: Covered area, accumulation rate, sliding rate. 3 megapixel sensor
Temperature Panel Custom T-type thermocouple Of temperature profile using Special Limits of Error T – type thermocouple wire. Attached to solid-state multiplexers with integrated cold-junction compensation. +/- 0.5 C
Power Monitoring Panel Custom Transducers with MPPT The panels are monitored using a proprietary DC power transducer, calibrated using traceable instrumentation to NIST. This transducer measures Vmp and Imp at the regular collection intervals. The use of a 99.7% efficient MPPT device ensures that the maximum DC power point of the panel <1%
Spectral Distribution Ocean Optics USB4000 Spectrometer High quality spectrometer for monitoring of spectral effects within the range of PV sensitivities. This can be very useful when monitoring the performance of Albedo on PV performance > 99.8% corrected linearity, spectral range 200 nm-1100 nm

External links

  • OSOTF at Appropedia
  • SEARC OSOTF Design and Operations Manual


  1. ^ Jump up to:b Solar panels for all seasons – Canadian Geographic May 2012
  2. Jump up^ Joshua M. Pearce, Adegboyega Babasola, Rob Andrews, “ Open Solar Photovoltaic Systems Optimization “Proceedings of the 16th Annual National Collegiate Inventors and Innovators Alliance Conference, Open 2012, pp. 1-7. open access
  3. Jump up^ Rob Andrews and Joshua M. Pearce, “ThePrediction of Energy Effects on Photovoltaic Systems Due to Snowfall Events” in:2012 38th IEEE Photovoltaic Specialists Conference (PVSC). Presented at the 2012 38th IEEE Photovoltaic Specialists Conference (PVSC), pp. 003386 -003391. Available:DOI open access
  4. Jump up^ Rob Andrews, Andrew Pollard, Joshua M. Pearce, “Improved Parametric Empirical Determination of Modules for Solar Photovoltaic Systems”,Solar Energy 86, 2240-2254 (2012). DOI,open access
  5. Jump up^ of snow on photovoltaic performance
  6. Jump up^ Examples:Construction Canada,Renewable Energy World,Kingston Herald,Reuters,San Francisco Chronicle,Txchnologis,Toronto Star
  7. Jump up^

About the author


View all posts