SKYLINE -- Reinterpreting the Horizontal Single-axis Tracker

SHANGHAI, Dec 4, 2018 /PRNewswire/ -- Skyline is the newest addition to Arctech Solar's product line, which joins the already existent products Arctracker Pro (ganged architecture) and SkySmart (single line, 2 modules in portrait) as the simplest horizontal single line tracker, with one module in portrait and length up to 90 modules. In this article, Arctech Solar will unveil details of Arctech's new product Skyline by analyzing different tracking systems in the global market.

1. Tracking Systems Architecture

All tracker architectures have their place in the market, depending on project specifics. Accordingly, each of architectures has pros and cons:

1) Single-row trackers

• Single-row trackers provide an extra level of flexibility due to their unidimensional nature, which avoids a possible E-W terrain constraint and fits better around odd-shaped boundaries.
• Despite the higher relative cost of Motors, gears and controllers on the single row trackers, there are fewer site obstructions, which may come handy for certain O&M activities.

2) Ganged trackers

• A ganged tracker has a bidimensional footprint and project designers need to take both E-W and N-S orographic contours into account, which often times call for site grading or reinforced linkage systems.
• The positives of a ganged architecture lay on the possibility of using a single driving mechanism and controller, which can move up to 400 kW of modules. This typically yields a lower cost tracker. Also, by having a linkage that already connects several rows, intelligent BoS designs can take advantage of it and avoid costly trenching.

All of this to say the most adequate product for the flat Jordan desert is not necessarily the same as the one for Chile, northern Spain or the US Carolinas.

2. Arctech's Tracking System Family

Realizing this fact, Arctech Solar decided to invest on the development of a family of trackers which can adapt to all situations. The current product offering includes:

• Arctracker Pro – ganged tracker with a rectangular footprint and central driving mechanism with rows with one module in portrait
• SkySmart – single-row tracker with two panels in portrait in a 45x2 configuration. This tracker is the shortest and the most adequate for difficult terrains as well as the best choice for bi-facial modules.
• Skyline – single row tracker with just a panel in portrait and up to 90 modules long. With shorter chord length and lower footprint, it allows for a significantly better cost per watt figure at the expense of slightly less N-S flexibility.

Different from other manufacturers in the PV industry, Arctech Solar has first-hand experience with three different architectures. Most of our competitors know their chosen architecture extremely well, but not all of them get their hands-on designing, manufacturing, testing and deploying many MWs of all three types of tracker.

3. Skyline Tracking System: Combined Benefits of All Single Row Trackers

At Arctech we have that experience and learned the merits and weaknesses of them all. We did not only hear about them. We experienced them across the whole lifecycle. That knowledge allowed us to filter the advantages of all architectures and combine them in our Skyline development to boost performance and lower cost, increasing the value proposition. When compared with ganged and 2V architectures, Skyline allows for the lowest tracker cost (lower loads and less prone to dynamic instability) and lowest installation costs (all work done at standing height and no need for heavy machinery).

Skyline presents four very significant competitive advantages with regards to other single line, one module in portrait trackers:

1. It is string powered, releasing it from the need of a dedicated PV panel.
2. It includes ~20% fewer posts per MW installed, which directly saves foundation materials and installation cost.
3. No gaps in between strings of panels, which improves land utilization
4. Includes a smart torque tube design, with variable section according with the different structural needs along the torque tube, dictated by static, dynamic and aeroelastic wind studies.

Let's elaborate on the 4^th characteristic a little bit, as it is also the enabler of the 2^nd and 3^rd characteristics.

Among all tracker components, the torque tube ranks at the top in terms of cost, being as high as 40+% of the whole structure. It is thus imperative we dedicate special attention to optimizing this component, as any optimization here has a large overall impact.

A single axis tracker is subjected to torsional and bending loading. These two states of loading will result in a combined stress in all tracker components. Figure 1 depicts the bending and torsional moments as well as the resulting stress allowance along a Skyline torque tube.

Fig.1 - Typical bending and torsional loading on a torque tube and resulting stress in terms of current/allowable (*from Arctech’s proprietary ArrowOne structural calculations software)

With the experience accrued through hundreds of MWs of SkySmart deployments, Arctech was able to understand the situations and portions of torque tube that are governed by torsion and bending and custom design a tube which responds to those solicitations accordingly. Trackers with 2 panels in portrait are more sensitive to wind effects and torsional effects. Trackers with a single panel in portrait have portions governed by bending.

Our novel torque tube cross-section design is proprietary and we won't show its exact geometry here, but our customers are already enjoying the increased stiffness and resistance of Skyline when compared to the other options in the market. All of this at a lower cost, enabled by a smart geometry which puts inertia only where it is needed.

At Arctech, being vertically integrated, we are more agile and can afford changing cross-sections without imploding a very heavy and complex supply chain. The enabler to a high performance and lower cost tracker is to know exactly where the different types of loading occur and responding without costly compromises

For queries please contact sales@arctechsolar.com

[About Arctech Solar]

Arctech Solar is one of the world's leading manufacturers and solution providers of solar tracking and racking systems. In the past 9 years, Arctech Solar has successfully set up overseas subsidiaries/service centers in America, India, Japan, Spain and Mexico. As of the end of 2017, Arctech Solar has cumulatively installed 13.5GW capacity and completed 800 projects in 15 countries. With a production capacity of 6GW and 4GW in fixed mounting structure and tracker field respectively (a total annual capacity of 10GW), Arctech Solar is now a reliable partner in the global PV tracking and racking industry.

For more information please visit: www.arctechsolar.com
For product sales and other enquiries: sales@arctechsolar.com

Photo - https://photos.prnasia.com/prnh/20181204/2316691-1-b