OpenSolar receives third-party validation of design tool’s accuracy

OpenSolar has released the findings of independent third-party assessments that: validate the accuracy of its solar design tool. By using OpenSolar’s design tool, solar installers can feel confident to provide customers with the most accurate PV designs to suit their solar needs. Combined with other key features of OpenSolar’s free-to-use platform, including access to a range of state-of-the-art hardware, a portfolio of competitive solar financing options, and on-demand custom permit proposals, the company enables solar installers to target more prospects. into booked sales, while saving time and eliminating the expensive licensing costs associated with other solar design and sales platforms.

As part of OpenSolar’s validation process, the company has partnered with PV Evolution Labs (PVEL) and the United States National Renewable Energy Laboratory (NREL) to provide independent third-party assessments of the accuracy of its design tool. The assessments include the following processes and findings.


OpenSolar has asked the United States’ National Renewable Energy Laboratory (NREL) to review the company’s 3D design tool. See the article : Generac acquires smart thermostat maker ecobee. NREL compared the shadow estimates from OpenSolar’s third-party 3D tool with on-site assessments using a SunEye, the world’s leading portable electronic shadow measurement tool for on-site assessment.

  • OpenSolar’s rating of Sun Access Values ​​was accurate to +/- 3%
  • The current US market leader turned out to be only accurate to +/- 5%

On-site assessment

OpenSolar engaged PVEL to assess the accuracy of its system-generated site models. On the same subject : Silfab opens second solar panel assembly facility in Washington State. PVEL took measurements both in the field and in OpenSolar on a wide range of roofs with different shapes and sizes.

  • OpenSolar’s assessment of the scale was accurate to within 1 foot 100% of the time (no other tool offers such a close tolerance)
  • OpenSolar’s pitch assessment was accurate to 4° more than 97% of the time (no other tool offers such close tolerance OR such high compliance)

Energy Modeling

OpenSolar’s energy modeling (the conversion of key inputs, including pitch azimuth and shading in the key output: production) is based on NREL’s most advanced System Advisor Model (SAM). The company partnered with PVEL to validate the integrity of OpenSolar’s implementation of SAM, against industry-standard energy modeling tools such as PVsyst or standalone implementations of NREL’s SAM. See the article : Michigan electric cooperative signs PPA for 150-MW solar project. PVEL found:

  • OpenSolar’s energy modeling is consistent with standard engineering practices
  • OpenSolar’s production figures are within 0.0%-0.2% of standalone SAM estimates
  • OpenSolar’s production figures are within 0.1%-1.9% of PVsyst’s estimates

To view and download the full reports, visit

“Our assessment of OpenSolar’s software confirms that the implementation of the SAM model engine for energy production is accurate and in line with industry standards for residential and commercial projects and that the 3D raytracing calculations of beam shading are as good or better than others. available products,” said Ryan Desharnais, technical director of PV Evolution Labs (PVEL). “We also sent survey teams to a wide variety of residential rooftops and verified the accuracy of OpenSolar’s physical location assessments. Taken together, these findings demonstrate that OpenSolar can produce high-quality estimates of power generation for solar projects.”

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