White Paper: Quantifying Your Bifacial Gains–Using Calibrated PVsyst Model Input Parameters to Accurately Predict In-field Performance

By Greg Beardsworth, Director, Product Management, Nextracker, Inc. and Amir Asgharzadeh Shishavan, Ph.D., PV Systems Performance Engineer, Nextracker, Inc.


Tracker-mounted bifacial PV is the most disruptive solar yield improvement technology since the introduction of the modern tracker. While designing and building a bifacial PV power plant is not much more difficult than building a monofacial power plant, modeling and optimizing a bifacial plant is far more complex. For bifacial to achieve its market potential, investors and financiers must be able to confidently predict bifacial performance. The ability to accurately model and measure bifacial performance is crucial.

The technical white paper presents Nextracker’s test methodology and findings with the goal of providing actionable content for developers, financiers, independent engineering firms, and performance engineers working to characterize fielded bifacial system performance.

The paper examines bifacial performance data from two different test sites, which show a strong correlation in bifacial yield gains across low and high albedo conditions. The paper also takes a deep dive into the calibration of PVsyst input parameters for the NX Horizon tracker in order to accurately predict field performance, demonstrating alignment between modeled and measured results.

Finally, the paper compares bifacial performance of the NX Horizon versus other single-axis 1P trackers. Measurable, repeatable, and consistent across all test conditions, side-by-side test results indicate that NX Horizon provides an additional 1.02% to 1.67% of DC-side bifacial gains as compared to other 1P single-axis tracker designs.

This white paper was written in collaboration with PVEL.

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