1P Vs. 2P Solar Trackers

Key takeaways

• A growing preference for 1P solar trackers is evident, driven by reduced costs, enhanced structural stability

• In regions like China, 2P trackers remain popular for specific applications, such as PV-plus (agricultural or aquatic PV systems), where their elevated height meets local needs

• For challenging terrains and windy sites, 1P trackers offer superior adaptability and reduced shading. However, 2P trackers may be preferred for stable, low-slope areas with suitable soil

• Single-row trackers are often optimal for large, open areas, while dual-row trackers are better suited for hilly European landscapes

Today’s solar trackers come with several module mounting options including 1P, 2P, 2H, 3H, and 4H. However, given that the horizontal (H) configurations are not bifacial-friendly, 1P and 2P have emerged as the mainstream choices, with several companies offering both platforms. Although 2P was the more popular choice in the past, it has been losing ground to 1P. This shift is underscored by recent product launches from several leading tracker suppliers, indicating a growing preference for the 1P platform.

Nextracker’s flagship 1P tracker NX Horizon, launched in 2015, has already seen significant shipments totaling 85 GW, according to Nextracker. The preference for 1P trackers stems from several factors. While customers were drawn to 2P products in the past, they have been increasingly favoring 1P trackers for their robust design. Contrary to the conventional belief that 2P products simply double the load, engineering calculations reveal that torque requirements for 2P trackers are 4 times greater, he emphasized. This increases the need for steel and multiple drive systems, affecting the overall design and dynamic stability. Moreover, Nextracker noted instances of failures in competitors’ 2P products in the field, which has bolstered the perceived reliability of 1P trackers (See Nextracker’s TrueCapture Solar Tracker Technology With Intelligent Control Systems).

In utility-scale projects, particularly in India, 1P trackers are gaining market share due to their cost effectiveness for building large-scale projects ranging from 20 to 50 MW, according to Frank Wang, senior technology engineer at Antai. This shift is largely due to cost considerations; 1P trackers generally cost less than 2P trackers. The higher costs associated with 2P trackers originate from increased installation heights and the additional time and effort required for installation and maintenance. A major challenge with 2P trackers is securing the modules to the tracker's table, as the large size and cantilever length of the modules, which ranges from 4.5 to 5 m, pose significant challenges to both the module frame and the fixing methods of the trackers.

Jenya Meydbray, Chief Commercial Officer at Nevados, said that the major US market has largely moved away from 2P systems. He advocates the shift, citing concerns with 2P systems, particularly wind-related failures. He points to project sites where 2P trackers experienced collapses or module issues, in contrast to Nevados' trackers, which showed zero issues under similar conditions.

Scorpius’ Jadhav, speaking from an Indian perspective, also observed a noticeable trend where companies are increasingly opting for 1P trackers over the previously popular 2P trackers. This shift is driven by a focus on cost-effectiveness, as 1P trackers offer advantages in terms of lower maintenance costs and higher generation efficiency. However, Sejas from Axial emphasized that the choice between 1P and 2P trackers isn't a matter of clear preference or competition. Instead, the optimal solution depends on the specific conditions of each project. Axial's own shipment data reflects a balance, with a nearly equal share for both systems. Site conditions play a crucial role in determining the most suitable tracker type. For terrains with steeper slopes, 1P trackers offer superior adaptability. Conversely, 2P trackers with less kg/MW might find it economical. Specific soil conditions are a key influencing factor, where factors like pile driving depth become critical. For 2P trackers, the running depth is 2 m, compared to 1.5 m for 1P trackers. Wind conditions also play a role; both systems operate in normal mode with wind speeds up to 50km/h, but they respond differently to higher windspeeds, especially with the stow positions. In stowing positions, the 2P mostly works like fixed tilt, whereas the 1P results in higher energy yield in such cases. The selection between 1P and 2P trackers involves careful consideration of topography, soil conditions, wind speeds, and maintenance requirements to ensure optimal performance and efficiency, according to Sejas (see Digital Solutions For Smart Solar Tracking).

Sun Yun Hua from TrinaTracker said that major Chinese solar tracker manufacturers favor the 2P configuration, while global manufacturers generally prefer the 1P setup. He believes the preference for 1P configurations among international firms aligns with demand in markets such as India, the Middle East and Australia. Additionally, he highlighted that in certain regions, including parts of China, Chile and the Middle East, the 2P configuration offers distinct advantages. For instance, in China, many projects integrate photovoltaic systems with aquaculture (referred to as PV-plus), necessitating taller PV panels – typically over 3 or 4 m.

The extended pier length required for 1P configurations drives up costs, making the 2P configuration more economical. TrinaTracker anticipates sustained demand for 2P solar trackers not only in China but also in Europe, the US and Latin America for PV-plus applications such as agriPV and aquatic PV systems. The company is actively enhancing its designs for 2P-configured solar trackers, with a particular focus on improving their wind resistance.

Single vs. dual row: Single-row and dual-row designs are the other options for tracker configuration. According to TrinaTracker’s Hua, there are no significant differences between single-lane and dual-lane solar trackers in terms of their applications. In Europe, the use of dual-lane trackers is common due to the continent's hilly terrain and the limited availability of open fields for large solar power plant installations. Single-lane trackers are generally longer, often exceeding 100 m, while dual-lane trackers are shorter, typically around 70 m in length. This shorter design makes dual-lane trackers particularly suitable for the varied topography of European landscapes. However, according to Meydbray from Nevados, for challenging sites with varying topography, independent row trackers are necessary to prevent row-to-row shading, which significantly impacts energy production. He claims that Nevados trackers excel in this regard, offering individual row tracking schedules calculated upfront based on topography, sun position and adjacent rows to ensure zero shading. This approach guarantees accurate energy modeling and eliminates the need for multiple consecutive clear sky days for calibration, a common drawback of machine learning-based trackers.

The text is an excerpt from the latest TaiyangNews Solar Trackers Market Survey 2024, which can be downloaded for free here.