Driven by the continuous pursuit of lower levelized electricity cost (LCOE), today’s tracker-based utility-scale photovoltaic (PV) project with bifacial technology demands advanced cost-saving tracker design, digitalized smart tracking solutions, and safety features against potential environmental stresses. Acknowledging the aforementioned industry demands, Nextracker, a key player in the tracker segment, has continuously evolved its products from design to digitization. In the given context, Antonio Sendin, International Sales Director, along with Antonio Buiza, Sr. Business Development Manager EMEA, pitched Nextracker’s TrueCapture smart control software (see Nextracker’s presentation here). Its advanced features make it suitable for higher latitude geography with high diffused irradiation.

Starting with a brief introduction about the American NASDAQ-listed company, Sendin described its flagship NX Horizon one-in-portrait (1P) tracker along with undulated terrain following (1P) NX-Horizon XTR tracker, both compatible with TrueCapture software. Taking over from Sendin, Antonio Buiza defined Nextracker’s TrueCapture technology as an intelligent, self-adjusting tracker control software.

Performance enhancement

This control software works based on 2 control modes – diffuse mode and row-to-row backtracking (R2R) mode. Buiza explained that the diffuse mode, a new feature, that tries to optimize the energy yield in diffused irradiance conditions by placing the panels skyward maximizes not only the global irradiance but also reflected irradiance to the bifacial modules. He emphasized that the latest cloud-tracking system under diffuse mode, enabled with smart models and sensors is capable of tracking the passing cloud over the PV site, eliminating the necessity to put the whole plant under diffuse mode. By recalculating the real-time irradiance every 2 minutes over the part of the plant affected by cloud shading, TrueCapture’s diffuse control mode helps to keep most of the plant tracking system in normal condition, while part of the plant remains in diffuse mode.

Its digital twin-based R2R backtracking mode ensures accurate row-to-row shade avoidance in complex terrain and minimizes the potential underperformance due to misalignment of tracker rows originating during the engineering to the construction phase, said Buiza. The company claimed its digital twin is providing the 3D mapping of the plant not based on engineering layout documentation or the site topography, but on real-time site layout data, boosting power generation. Along with the conventional backtracking mode, the latest TrueCapture offers an additional Split-Boost mode, which ensures just the lowest half of the portrait-configured half-cell modules will be covered under the shadow during early mornings or late evenings, but the modules will be facing the sun instead of being nearly flat. Buiza demonstrated TrueCapture’s working principle covering all available modes for a whole day through a video. Here, in mid-afternoon or before the end of the day with some clouds in the sky, the software will activate the diffuse mode followed by lifting the tracker angle to the +60° position when the sky gets clear and in the late afternoon it will start the traditional backtracking or shade avoidance until it decides to go to split-boost mode, which will be more beneficial compared to shade avoidance. The company claimed to have a maximum of 4% additional annual energy gain by utilizing TrueCapture software.

Enhancing system reliability

Along with its optimized power generation capability, TrueCapture ensures PV system operational functionality for extreme environmental events like hail-storm, flood, and snowing. The TrueCapture single advanced software license includes Navigator HMI – a SCADA system equipped with advanced functionalities including hail-stowing, flood-stowing, and snow-stowing, as well as multiple management tools. The hail stowing mechanism in the navigator interface brings the tracker to the hail stow position before the storm happens by using forecasting systems and determining the probability of hail, the distance from the storm, or the size of the hail with potential damage.

Bankability

The company claims TrueCapture’s advanced features and potential yield improvement are verified by some of the leading Independent engineers like Enertis, ICF, and RNA. For example, Enertis with its modeled gain value respective to diffuse and R2R backtracking mode, obtained from a controlled environment or controlled modeling of the real plant, becomes less than the actual measured value. Upon request, these independent 3^rd party engineer’s reports can be accessed under Nextracker’s bankability report. Thus, by using these independent advisors its customers can cover the cost of TrueCapture in the financing of the project, says Buiza.

Additionally, customers can also choose Nextracker’s in-house TrueCapture energy yield evaluation capability in case the independent advisor’s support is inadequate. He substantiated his claims by providing one case study in a US-based plant, where it has divided the plant into 2 blocks – one is control block and the other one is just to measure the diffuse gain. It estimated a gain of around 1.9% and close to 2% after 6 months.