Tracking Trackers: We look at what’s new with these seven solar trackers

What are you looking for in a tracker? Longer rows with fewer spans? A two-up bifacial module setup? A simple central drive configuration with reliable bearings? More self-powered options? There are a lot of trackers in the segment, and we wanted to highlight some of the cool, innovative features outside of the market share leaders that reduce costs, ease installation or improve reliability.

Arctech

arctech

Three tracker styles to match every solar site

Arctech offers three tracker designs: The Arctracker Pro is its centralized tracker with push-pull design that is the best for flat land. The SkySmart is a single-row design with two modules in portrait that has fewer posts and is perfect for bifacial modules, and the SkyLine is a single-row design with one module in portrait.
Arctech makes the majority of its products with the support of two enormous factories, with a third on the way in 2019, to better control costs and quality.

Key hardware

  • All of Arctech’s trackers have its new D-shaped torque tube that adds stability and saves material.
  • Single-row trackers are powered from the string rather than from the batteries.
  • A beefy bearing was recently added that can handle a 20 percent N-S slope and stop the translation of weight.

Software

“Most of what we are doing is ensuring interfaces to client’s SCADA systems,” says Guy Rong, president of Arctech Solar. “We have a number of alarms in the rare case something happens to the system. Beyond this we are building software to create more accuracy on a row-by-row basis. We will announce when this is available.”

Case study

A 172-MW project in Telangana, India, had three main challenges that were solved by the design of the Arctracker Pro.

Challenge 1: Rough terrain and uneven slope. Solution: Arctech took advantage of special linkage and different post lengths to offset land contour variations and, at the same time, keep the high density of PV modules in available land and maintain high energy yield. Moreover, tracker sizes were specially designed to make best use of corner areas of land.

Challenge 2: High wind. Solution: Arctech Solar reinforced the tracking system by adding 25 percent more dampers to ensure stability and reliability of general operation and avoid damages caused by strong wind.

Challenge 3: Installation within timeline. Solutions: Installing 172 MW at a single site within the timeline was a challenging task for the EPC. In India, it’s not always easy to find skilled man power in remote areas. To solve these issues, the Arctech engineering team collaborated with the EPC to finalize installation phases well before shipping. Posts were shipped first to make sure the civil work started early while Arctech’s project managers gave tutorials on demo tracker installation so that all teams could start work simultaneously.

Nclave

nclave

Recently acquired by TrinaSolar, this international tracker has beefed up its design

Spain-based Nclave keeps on expanding. Founded 12 years ago by the Clavijo Family, it integrated with MFV in 2017. Nclave has installed over 2.5 GW worldwide. Earlier this year, the company teamed up with Trina Solar, a Chinese supplier of global solutions for the solar sector, to be a part of its TrinaPro utility-scale solution, which eventually led Trina to acquire a controlling interest in Nclave.

Structure

Nclave has developed and patented a module mounting design, the Nclave Clamp, that reduces assembly time of modules by more than 75 percent with as low as 50 manhours per MW. It also lessens the weight of the material by more than 30 percent. It includes UL-compliant integrated grounding features and has been load tested to UL and IEC standards.

Nclave separates the tracker assembly from the module assembly process to ease installation. The registered purlin allows the system to be pre-assembled on the tracker so modules can be installed with only a nut driver. Installers get rid of dedicated hardware for module installation (no more clips, bolts or rivets) as the U-bolt brackets secure module, purlin and clamp all together with just two nuts: a sandwich-like concept.

Software

The Nclave tracker controller is part of smart PV solution TrinaPro. The tracker controller is connected with the inverter in order to boost energy yield production: the optimized matching among components and the “Edge Computing” algorithm integration of TrinaPro can improve system stability with higher power generation.
The controller is empowered with a smart O&M system on a cloud platform that analyzes and processes data to optimize the system’s operation model and ensure the system runs smoothly and efficiently.

Solar FlexRack

solar flexrack

We featured this in more detail right here.

Tough, reliable, and cost-competitive, Solar FlexRack introduces their new, advanced TDP 2.0 Solar Tracker for commercial and utility-scale ground mount solar installations. The TDP 2.0 Tracker’s new BalanceTrac design offers more modules per row (up to 90), a rotational range of up to 110° and is compatible with 1,000V and 1,500V crystalline and thin film modules. This solution allows for shorter piles and lower per-unit fixed costs for balance of system savings. The combination of complete project support services and this next-generation technology enables solar power plants to increase energy yield while significantly reducing project risks. The results are cost savings across your solar project budget.

Soltec

soltec

Smartly designed structure offers slick wire management

Soltec, a manufacturer and supplier of single-axis solar trackers and related services, has installed its trackers all over the globe for more than a decade now, but the company says 2017 was its best year so far, showing over 200 percent revenue growth. The strategic move to the United States in 2015 has coincided with additional market share in 2017, amid market uncertainties and strong competition.

Structure

The DC Harness StringRunner wire management solution is a proprietary standardized component of Soltec’s SF7 tracker. It performs the functions of combining fused PV source circuits and cabling a homerun trunk circuit, all enclosed within the tracker torque tube, to a DC power switch for off-take. It eliminates the traditional fused combiner box and other cable management materials and controls the power output of eight trackers typically around 240 kW.

Soltec says the cost benefits come from the reduction of materials and related operations in manufacturing, power plant design, purchasing, supply and installation. The net cost benefit is a 30 to 35 percent reduction of installed first-cost compared to the traditional exposed installation of bundled copper wire circuits with a traditional combiner box. Installation labor is reduced by 75 percent thanks to less material and fewer manual operations including wire connections.

There are yield-gain benefits too with a reduction of IR cable losses, reliable low-resistance connections and factory dimensioned trunk cable sizing. The elimination of cable-management backside shading increases tracker compatibility with bifacial module technology.

Software

Comparative tracker yield-gain elements are both standard and site-dependent. Principal to site-dependence is asymmetric backtracking control to modify tracking position in the case that terrain irregularities cause inter-row shading in morning and afternoon hours, a case that is avoidable on flat terrain.

Soltec’s TeamTrack asymmetric backtracking control solution achieves both yield-gain and cost reduction benefits in tracker technology, achieving up to 6 percent yield-gain over the alternative of standard tracking on irregular terrain, and enabling cost reduction of earth-grading on contours and steps. The TeamTrack differs from other backtracking solutions that incorporate an auxiliary PV module and feedback response mechanisms that can add cost and vulnerability by instead performing the task straightforward with programmed operation and robust tracker position control.

The TeamTrack control algorithm works with NREL sun position data versus programmed constants of local irregularities (that never change) to calculate and execute backtracking movements and avoid inter-row shading. TeamTrack is part of comprehensive tracker positioning control that includes sensing and response to cloud cover, snow cover, standing water level and wind regime.

Schletter

schletter

New tracker product with self-locking mechanism now available

Although the U.S. arm of Schletter filed for bankruptcy, the Germany-based headquarters is still chugging along. At this year’s Intersolar Europe, Schletter Group presented its new tracking system.

Hardware

The core feature of the new Schletter tracker is that it combines the stability of a fixed mounting system with the additional yields of a tracking system. This is achieved by the drive concept: While most other tracking systems use hydraulic dampers or similar supporting structures to mitigate the vibrations and torsional forces caused by the wind, this Schletter system features a drive system with a self-locking mechanism. Each post locks as soon as the row has stopped moving. This newly-developed and soon to be patented drive system fully eliminates vibrations over the entire row which can be caused by wind. Therefore the system, while at rest, has the properties and durability of a fixed mounting system and is designed to withstand wind speeds of up to 161 mph. It thus completely avoids the dangerous galloping effect.

The second feature that stands out is its efficiency, achieved through its large wing-span and ground cover ratio. Each row can be up to 393-ft long and is driven by one centrally located motor. At 13 ft in width, each row is wide enough to hold either two panels oriented vertically or four horizontally, thus up to 574 sq yds of solar array can be installed per row and motor. This allows operators to make optimal use of the available land and a ground cover ratio of more than 50 percent can be achieved.

Software

The tracker has a rotational range of 60 degrees and is controlled through wireless technology, which completely obviates expensive wiring for both power supply and communication. The motor and the control systems are selfpowered by a dedicated PV panel in each row with a battery pack. To make O&M easier, mechanical connections between the rows have been deliberately avoided. This allows unhampered vehicle access between the rows, for instance during servicing and maintenance work.

GP JOULE

gp joule

GP JOULE’s single-axis tracker passes 20-year reliability test

The PHLEGON single-axis tracker from GP JOULE Canada Corp. passed a series of accelerated life-cycle tests conducted by the Southern Alberta Institute of Technology (SAIT) in Calgary. The Institute’s Green Building Technology Lab and Demonstration Centre confirmed PHLEGON’s long-term reliability within a wide range of environmental conditions and proved its performance in extreme northern climates. SAIT’s Accelerated Life Test Report shows that GP JOULE’s active tracking technology provides proven results in the Northern Canadian and U.S. markets where fixed-tilt PV has been dominant.

SAIT cycled PHLEGON’s mechanical components continuously 7,305 times over a 19-day period to simulate two decades of functionality. PHLEGON initially underwent the tests without environmental factors, and then went through another round that simulated extreme conditions including grit, freezing rain and sleet. The test included a deep freeze below -20C, confirming sensitive components function under extreme temperatures. “Freeze-thaw” tests mimicked the effects of spring and fall on the tracker, flooding moving parts with water before immediately exposing them to below-zero temperatures. The actuator, responsible for controlling and rotating the solar panels, completed both the mechanical and environmental rounds of testing — essentially 40 years without failure.

“GP JOULE wanted SAIT to test two things. First, how the system will operate in Alberta’s climate and second, what the cost of operating and maintaining the PHLEGON over a 20-year lifespan will be,” says Tom Jackman, SAIT’s principal investigator. “Our testing protocol introduced freezing conditions that were not considered in their original test plan, resulting in substantial ice buildup and additional weight. All components tested without failure.”

SunLink

SunLink Tracker

Updates strengthen the TechTrack design

SunLink’s single-axis tracker TechTrack is one of the quickest mounting systems to install, largely due to the simplicity of every component designed to eliminate inefficiencies and optimize energy production. The company is responding to the current environment, with customers looking for faster installation to keep up with their volume of solar projects and ultimately reduce field labor and associated installation costs, with some tweaks to its tracker design.

Hardware

One change is a new bearing and pivot design that arrives on site preassembled. The new and improved bearing design provides enough room in the stabilizer stroke (SunLink active damper) so that the system no longer needs to be rotated. Instead, the stabilizer mount position can be set from a measurement, saving substantial installation time. And with the preassembled bearings, installation crews can immediately install the component, saving valuable time in avoiding additional assembly of multiple parts in the field.

An additional design benefit enables drop-in torque tubes, eliminating the requirement for specialized jack equipment. SunLink also improved the durability of its pivot and bearing to withstand the rigors of construction crew handling on the project site.

“Another way we’re is reducing installation time is by revisiting our slew arm,” says Kate Trono, SVP of product, SunLink. “With a more streamlined design, we’ve eliminated the need for multiple or expensive custom tools and install kits that can sometimes add another $10,000 to a project. Our redesigned slew arm can be installed with standard tools, reducing the number of components, labor time and additional expenses.”

Feature enhancements like these may seem like small improvements, but the pay-off is big when you consider the reduction in labor, installation time and reducing your overall solar project cost.

— Solar Builder magazine

U.S.-based Schletter subsidiary files for bankruptcy after premature product launch

Schletter

The Schletter Group sent word that it’s reorganizing its business in the United States. The U.S. subsidiary Schletter Inc, based in Shelby, N.C., has filed for Chapter 11 proceedings in order to sort out its current financial situation. Business activities are to be continued in close cooperation with clients and creditors.

“Filing for Chapter 11 proceedings at our U.S. subsidiary does not mean that we as a group are withdrawing from the U.S. market”, the group’s CEO Tom Graf commented. “North America remains an important and growing market for our brand and we will continue to have a strong presence there.”

The current financial situation in the U.S. is primarily the result of launching a new product before it was ready for high volume production, combined with the effect of the solar tariffs. The U.S. subsidiary, Schletter Inc, under its previous management overextended itself by acquiring a number of large scale projects involving a new product (G-Max), which it had solely developed in and for the U.S. The cost of carrying through these projects was significantly higher than planned due to the premature launch of the new product. It is this considerable financial burden which ultimately made this step necessary.

Although the product launch was challenging and there were significant operational issues, there was a significant volume of product deployed and the customers were pleased with the results. Some of these systems, in fact, stood up very well during the hurricanes in 2017. “With that success, and with the manufacturing issues resolved, our G-Max mounting system will continue to be the flagship offering for utility scale installations in North America”, Schletter Inc.’s CEO Russell Schmit commented.

RELATED: Bill to undo Trump Tariffs introduced in Congress

“The Chapter 11 proceedings now enable us to reorganize the U.S. company’s finances as we move forward”, Graf said. In parallel with Chapter 11, the German group is also filing for Chapter 15 in the U.S. regarding Schletter Inc. This relatively new amendment to the U.S. Bankruptcy code was introduced to coordinate cross-border cases. It provides the necessary legal framework to closely tie the U.S. proceedings to those at its German mother company, Schletter GmbH. Since March Schletter GmbH has been using the German equivalent of Chapter 11 proceedings in order to restructure its finances as debtor in possession. Other companies of the group are not affected by the proceedings.

In the meantime, the proceedings in Germany are making good progress. A few weeks ago a structured investor process was started and more than a dozen interested parties from Germany and abroad are currently reviewing the company’s accounts. “Investor interest is pleasingly high, which shows the strength of the Schletter brand”, emphasised Graf. Production, sales and services of Schletter Germany, and in fact all other companies of the group that are not affected by the proceedings, continue as normal. The goal is to complete the proceedings by this summer.

Even under the ongoing restructuring, the Group has been able to conclude in recent weeks a number of interesting new orders with a volume of over 20 MW. Those include projects in Germany, France, the Netherlands, Hungary, Senegal and Jordan. Preparations for Intersolar, the largest solar trade fair in Europe, which is being held in June, are also under way. There, Schletter will present for the first time a tracker system, developed specifically for the U.S. and the Australian markets. A number of other product innovations will also be on display such as the FixGrid 2018, which has again been improved in terms of capacity and ease of installation.

— Solar Builder magazine

Watch: How a single person can install Schletter’s G-Max fixed tilt racking

Steel solar mounting systems manufacturer Schletter kicked off its new blog last week with a quick tutorial on how to install its next generation racking system: G-Max. G-Max’s fixed-tilt construction is ideally suited for utility-scale installations, but here’s the wild part to us: The G-Max system’s fast and easy installation is so simple that a single person can install the girder, head adapter, and strut without assistance.

  1. Position the strut onto previously installed lower location bolt.
  2. Position head into upper location bolt.
  3. Install bolt at upper post.
  4. Tighten post bolts using 19 mm socket. The post will pull in tightly.
  5. Mark all the tightened bolts for quality control.

If you don’t believe it, check out the video above.

— Solar Builder magazine

The ‘Carportunity’: How our electric vehicle future means big things for solar carports

California’s Franchise Tax Board complex

Electric vehicles taking over the road is no longer a question. Sales of plug-in hybrid electric vehicles and all-electric vehicles have surged recently. So now the question is where are all of these things going to get their juice?

A new study from the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) quantifies how much charging infrastructure would be needed in the United States to support various market growth scenarios for plug-in electric vehicles (PEVs). NREL notes that most PEV charging occurs at home, but widespread PEV adoption would require the development of a national network of non-residential charging stations. Strategically installing these stations early would maximize their economic viability while enabling efficient network growth as the PEV market matures. NREL says about 8,000 fast-charging stations would be needed to provide a minimum level of urban and rural coverage nationwide.

No one asked us, but we think carport developments have a big opportunity (a carportunity!) to lead the way. The segment is seeing notable reductions in system costs and installation timelines that only make more projects viable.

Quest Renewables

The Value of Expertise

There is enough institutional knowledge among the chief carport construction companies now to give developers and larger investors confidence. Feast your eyes on California’s Franchise Tax Board complex, for example (pictured above). Developed by DGS-Building Property Management and installed by Ecoplexus at one of the largest business campuses in northern California, it is the state’s largest carport installation (10,400 PV panels), covering 1,276 employee parking spaces, spanning over 622,000 sq ft and generating 3.6 MW.

The project was made possible because of Baja Carport’s specialization in pre-engineered, pre-fabricated high-tensile, light gauge steel structures. And in chatting with its team at SPI this year, we’ve learned the company has been able to further streamline the costs of its system.

Then there is 4 S.T.E.L. and its standardized processes. Carport projects involve a ton of engineering and civil approval. 4 S.T.E.L.’s staff of engineers, project managers and drafters can design and erect a carport in their sleep at this point, but the big value comes in swift preapproval of its designs with the California Division of State Architects among other strict jurisdictions and building departments. Design preapproval can literally shave months off certain project timelines.

Park-onomics: Best practices for constructing cost-effective carport projects

Carports are certainly spreading beyond California too. At Michigan State University (MSU), Inovateus Solar is nearing completion of a 14-MW solar carport project spanning five parking lots and 700 sq ft on the East Lansing campus (pictured below). Using Schletter’s Park@Sol concept, the design is a maintenance-free, lightweight aluminum system with canopies standing 14-ft tall at the lowest point to provide enough room for recreational vehicles to park during football season. The carport install is expected to generate 15,000 MWh of electricity annually for MSU with projections showing a savings of $10 million in electricity costs over the next 25 years.

Schletter

Disruptive Designs

Key to the Schletter approach is its Micropile foundation, a hollow metal rod installed deep into the ground (pictured to the right), that requires less concrete material to accomodate even high wind and snow loads.

“The technology innovation of using Schletter micropiles as foundations and precast concrete pads, in addition to the engineering design, cut the construction schedule in half and minimized the risk factors in a rainy environment like Florida,” said Javier Latre Gorbe, VP of Technical Operations for ESA Renewables.

A newer entrant into the carport system space, Quest Renewables, has an especially exciting concept. Hatched as project at Georgia Tech Research Institute in 2011, the design received a work grant from the DOE’s SunShot Initiative and was commercialized in 2014. The hook here is a triangular support structure that requires less steel and allows for most of it to be assembled on the ground (pictured above).

Solar carports will spread across the country as costs decline

A vehicle auction company in Elkridge, Md., put in a 304-kW system and selected the Quest Renewables QuadPod to reduce foundation counts by 50 percent (using 50 percent less steel) to mitigate the poor soil conditions. From site survey to powering up, the system was completed in 45 days with minimal interruption to the parking lot. Another project in Portland, Maine, needed to minimize disruption of the work area. The 90 percent ground-level construction allowed it to be built in just eight days from start to finish. This first parking garage canopy install in Maine will sustain 112 mph winds and 50 psf of snow.

There’s a long way to go to fill in that void NREL is talking about, but it’s a start.

— Solar Builder magazine

Mounting Pressure: Today’s large-scale PV boom demands new levels of service from racking companies

Solar FlexRack

For the first time ever, in 2016, U.S. solar ranked as the No. 1 source of new electric generating capacity additions on an annual basis. In total, solar accounted for 39 percent of new capacity additions across all fuel types, and these big numbers are coming via big installs as the utility-scale segment grew 145 percent from 2015.

“In a banner year for U.S. solar, a record 22 states each added more than 100 MW,” says Cory Honeyman, GTM Research’s associate director of U.S. solar research. “While U.S. solar grew across all segments, what stands out is the double-digit gigawatt boom in utility-scale solar, primarily due to solar’s cost competitiveness with natural gas alternatives.”

The trend shows no signs of reversing, and as utility-scale solar projects continue to boom, the industry demand for material and logistical services will keep increasing pressure on suppliers like never before.

Raw materials bottleneck

“It’s a simple matter of supply and demand,” says Chuck Galbreath, VP of supply chain at SunLink. “If I have more time, I can find more options and drive down costs. When schedules are compressed and I’m forced into a tight delivery window, I have to go with the supplier who is able to deliver in the time allotted, which allows less room for negotiation.”

Others agree: “We often encounter requests for expedited finished product that can be more aggressive than the lead times from the steel mills. For our proprietary racking systems, OMCO is now maintaining a responsible level of steel inventory to support these instances,” states Todd Owen, General Manager of OMCO Solar.

The time pinch has led to more in-house manufacturing. “The top five racking manufacturers have reached economies of scale where additional volume no longer decreases price, forcing manufacturers to vertically integrate by producing more parts and material in-house,” says Paul Benvie, VP of engineering at TerraSmart.

Because the sector is so dependent upon the steel market, finished product pricing can be volatile. The recent anti-dumping lawsuits spurred market increases that were felt in all steel industries, including solar. Benvie says TerraSmart has countered the pricing roller coaster by making strategic hedge buys and leaning on suppliers to honor and hold pricing so they are capable of manufacturing product at a reliable price point.

To help combat delivery delays, more mounting companies also are establishing regional centers. “Steel delivered to and from opposite coasts can have a significant impact on costs and schedules,” Benvie says. “Strategic manufacturers have set up facilities that are centrally located and/or have different branches at opposite ends of the country. For example, TerraSmart has opened a new manufacturing facility in Columbus, Ohio, and can manufacture identical parts out of the Southeast, Southwest and New England.”

RELATED: We look at the value decentralized tracker systems bring to a project 

Timelines keep shrinking

“As the solar industry matures and adopts the more typical rigid large-scale construction approach to project schedules, timelines have been compressed and suppliers are now expected to adhere to strict, tight daily schedules,” says Nick Troia, VP of corporate quality and project management at SunLink. “It is a more professional atmosphere that in some cases is straining the less sophisticated suppliers.”

The compression is substantial: “We ask customers for a 12-week lead time, but in this market we are lucky if we get eight,” says Larry Reeves, a project manager for Array Technologies Inc. (ATI). “Schedules are crazy now.”

Seasonal variations also intensify weather constraints. “The solar industry is challenging, as many financiers, developers and EPCs push to close projects out in Q4,” Benvie says. “In New England, this can be increasingly challenging with projects kicking off as the daylight hours get shorter, temperatures drop and field conditions deteriorate.”

“Without getting into the dollars and cents, delays can be very costly, such as the triggering of liquidated damages that could accumulate at thousands of dollars per day or by hindering project completion for a tax credit deadline,” observes Troia.

Losses can be the cost of customer maintenance, too. In some of these unavoidable situations, someone involved in the project has to recognize and proactively eliminate a delay before it happens.

“We believe we are truly partners with our clients, so we commonly shoulder costs or increase productivity to minimize the sting of a delay, regardless of who caused it,” Benvie says.

Next, we look at the turnkey services and systems designed for saving time on project development.

— Solar Builder magazine