Why mass customized solutions win in utility-scale solar

SunLink Tracker

SunLink started designing solar mounting systems in 2004 when the concept of commercial rooftop solar was novel. The first systems were custom designed for the particular application, because everything was new. Needless to say, these first arrays were inordinately expensive by today’s standards, but the success of those installations helped pave the way for a booming distributed energy economy.

Solar, however, is relentlessly cost competitive. Smaller installations can’t absorb the soft cost of custom engineering. At the same time, no two solar projects are the same, which on the surface mandates custom engineering. Mass customization can make customization at scale cost-effective.

What is mass customization?

Legos are a great way to describe mass customization. The Legos are standard, but you can configure the blocks to build whatever you want. Here are a few examples of this approach in working in utility solar:

Take a single-axis tracker. The tracker needs to be engineered for a wide range of environmental conditions and any row length (since string length varies by project and space constraints require partial rows). This could lead to countless combinations of torque tube lengths and thicknesses. In a mass customized solution, a half dozen or so standard torque tubes are configured to meet the unique needs of the project. Limiting the number of parts greatly increases supply chain and engineering efficiency.

Similarly, the number of foundations can be increased to increase load capacity without designing a new part. Cleverly designed module mounting hardware accommodates the most common PV modules with no changes. With TechTrack’s dynamic stabilization feature, SunLink brings an important new tool for efficiently configuring resistance to wind loads. The unique nature of solar sites is designed into products so that manufacturers can respond to opportunities quickly, cost-effectively, and with a fully-vetted solution.

SunLink

Innovative manufacturers are moving beyond traditional racking and into software and services. In doing so the focus shifts from catering to the unique needs of the project to the unique needs of the customer, yet the benefits of mass customization remain.

As an example, SunLink recently launched product packages to complement the mounting systems. What differentiates the product packages is that they integrate hardware, software and services to serve a customer’s specific needs. The TechTrack Standard Package, Cold Weather Package, and Pro Package allow us to standardize solutions for common needs while giving the customer choice in what to pay for.

The product packages are analogous to the options available when buying a car. Paint color, drivetrain, and interior options cater to different customers, but all are built from the base model car.

Mass customization also guides the development of software. Different modules are implemented depending on whether the user is an O&M provider, an EPC or a developer. The best systems are highly flexible with provisions to connect to a wide variety of data monitoring systems, device types, SCADA implementations, etc., because inverters, trackers, storage systems and other intelligent hardware are constantly changing, as are the requirements of the utility and the ISO.

Modern communication protocols are critical to strong yet flexible systems. Modbus, developed in the late ’70s and early ’80s, is still the most common protocol for energy devices and SCADA systems. It should be no surprise, however, that a 30-year-old protocol isn’t up to the task of two-way communication between thousands of modern intelligent devices and numerous software services. Worse still, many software packages have limited ability to communicate with other applications. If you want to look at the performance of a solar portfolio but have several data monitoring systems, you may be forced to print reports from each system and manually input the data into a spreadsheet. This is a failure of technology.

In tech, RESTful APIs enable efficient, flexible communication between devices and services, allowing developers to build applications that leverage other applications. At SunLink, we’ve incorporated this approach by developing VERTEX for remote tracker performance monitoring and O&M benefits to provide bankable data that will unlock new value in the energy industry. An additional value in using a RESTful API enables Vertex as a standalone application, as well as simple integration with other products and services (thereby reducing software product bloat).

Mass customized solutions win in utility solar because they drive down cost while accommodating the needs of the project and customer. The next time you are looking at the design of a solar plant, or anything else for that matter, consider what’s led the products to be standardized, customized or mass-customized.

— Solar Builder magazine

The role of system design, labor in reducing utility-scale solar costs in 2018

According to the U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL)’s U.S. Solar Photovoltaic System Cost Benchmark Q1 2017 report, the installed cost of solar fell to record lows last year due to the continuing decline in PV module and inverter prices, higher module efficiency, and lower labor costs. Utility-scale solar system cost alone grabbed headlines as costs fell nearly 30 percent last year. Thanks to the Trump Administration, however, we may see the first cost increase after a nearly seven-year decline in the installed cost of solar due to the new import tariffs placed on solar (30%) and steel (25%) earlier this year.

Price-squeezing is nothing new in the solar industry, but the tariffs are putting additional pressure not only on module pricing but structural costs as well. And with field labor costs also on the rise, especially in states with union labor mandates, there is little to no room for margin growth.

To meet customers’ ongoing efforts to reduce solar project costs, SunLink, a utility-scale solar mounting system and tracker company, is applying innovative engineering design and technology to shift the industry mindset from lowest cost, commodity components to value-add, smart tracker designs that deliver more intelligent energy.

Lessons from tech industry: Engineering efficiency

SunLink President & CEO Michael Maulick saw this opportunity when he took over the helm four years ago. As a long-time technology executive, Maulick was surprised to find the solar industry so fixated on “pounds of steel” as opposed to looking at design innovation as a means to create a better product.

“When we set out to enter the tracker market three years ago, we knew we had to create a more effective product that would not only generate optimal energy production but also be cost-efficient,” said Maulick. “By rethinking a traditional damper and innovating to create the dynamic stabilizer design, we managed to reduce steel in the system by 17 percent, which with today’s steel tariffs, are a huge cost savings to our customers.”

SunLink

Every component in SunLink’s single-axis tracker TechTrack is designed to eliminate inefficiencies and optimize energy production. And when you’re operating in a tariff heavy business environment, shaving time off of hardware and soft costs like installation can contribute towards reducing your overall project costs. In less than two years, SunLink has installed more than 300 MW of trackers with customers responding positively to the company’s dynamic design approach for increased responsiveness in various environmental conditions, improving durability and reliability in the field. That approach has increased SunLink’s project range, from projects with higher wind conditions to projects with higher snow loads without increasing the steel requirement.

SunLink’s latest tracker enhancements are aimed at reducing field labor and installation costs.

“We improved our pivot design to provide enough room in the stabilizer stroke so that the system no longer needs to be rotated to complete installation. Instead, the stabilizer mount position can be set from a measurement, saving substantial installation time,” said Kate Trono, senior vice president of product. “The pivot and bearing arrive onsite pre-assembled, enabling immediate installation, saving valuable time in avoiding additional assembly of multiple parts in the field.”

An additional design benefit of the improved pivot is the drop-in torque tubes feature, which eliminates the requirement for specialized jack equipment or a larger crew to hold the tubes in place. According to Trono, with improved durability of the pivot and bearing, the tracker components can also better withstand the rigors of construction crew handling on a project site.

Another key reduction in installation time came from revisiting the slew arm design. A more streamlined design has eliminated the need for multiple or expensive custom tools and install kits that can sometimes add another $10,000 to a project. The 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 payoff is big when you consider the reduction in labor, installation time and overall solar project costs.

— Solar Builder magazine

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

PV Pointer: How to optimize PV system structural design for environmental hazards

snow-covered solar panels

According to a recent study by SolarPower Europe, new solar photovoltaic (PV) capacity installed worldwide in 2016 reached more than 76 gigawatts. This was largely due to dramatic growth led by the United States and China, with both countries almost doubling the amount of solar added from 2015. Globally there is now more than 305 GW of solar capacity, and with the increase of solar projects around the world, different climates, topography and other geographic considerations are making design for the environment increasingly important to ensure the integrity of the system over its lifetime.

PV plants are subject to a multitude of threats from the physical environment over the span of their lifetime. These threats must be taken into consideration during structural design in order to mitigate the risk to the system. With PV plants now being installed all over the world, the applicable risks will vary greatly depending on the geographic location. Therefore, the design of each plant must be thoroughly evaluated for its unique set of potential environmental hazards.

Environmental Loads

The first decision to make in determining the environmental loads on a plant is to identify the appropriate risk category for the plant. Building codes around the world use this categorization to determine the probability of occurrence of the design loads, or in other words, how extreme the design loads are. More critical solar project facilities can be designed for a higher risk category, and therefore, for loads with a lower probability of occurrence and a larger magnitude. For example, a rooftop system at a hospital that is required to remain operational after a design level event will be designed to higher loading conditions than a utility-scale facility behind a fence that is not supplying critical power to the grid.

Check out all of our PV Pointers here

Evaluating Different Types of Environmental Loads

When designing a PV plant, the environmental loads that usually first come to mind are wind and snow loads. However, certain architectures or geographical locations will necessitate consideration of seismic, ice or thermal loads as well.

Due to the large surface area and low weight of PV arrays, wind loads are often the most critical environmental forces. Consideration must be taken for both the potential wind magnitude at the site as well as surrounding topographic features that may amplify or weaken the wind as it approaches the PV plant. In many designs, wind tunnel test data is used to most accurately predict the resulting loads on a particular architecture. More accurate prediction of the wind loads allows for optimized structures that still meet the desired levels of performance and reliability.

Snow is another common critical design load on many PV plants. Rooftop and fixed-tilt ground-mounted systems are particularly vulnerable due to the relatively shallow slope of the modules. In addition to the snow’s weight on the tables, the designer must consider snow accumulation between tables, drifting and the potential need for an elevated system to allow for snow shedding. Tracker systems allow for some mitigation of the snow loads by tracking to maximum tilt to shed a large portion of the snow.

Seismic loads are less discussed in the solar industry, but they can be a significant concern in locations with high snow load and moderate to high seismic risk. Since the snow weight is considered part of the seismic mass, the resulting loads can be significant as snow accumulates (force = mass x acceleration). Many PV plants use wide flange post sections which have significantly lower strengths in one direction than the other. As earthquakes act in all directions, this is a vulnerability that needs to be expressly accounted for in design.

Ice, temperature and flooding are additional environmental risks that need to be examined for PV plants in some locations. Ice can add weight to a table and can be a concern for freezing up moving parts. Temperature becomes a concern with systems like trackers where there are long continuous members such as torque tubes. Thermal swings such as those found in desert climates can cause enough expansion or contraction of the steel along a row to result in non-trivial forces on the system. Finally, systems in floodplains must take the expected flood levels into account in the architecture and evaluate whether to design an elevated system.

Designing for these potential load effects helps to mitigate the risk to a PV plant from environmental hazards, thus increasing the overall reliability of the system throughout its lifetime and providing better value to the plant owner.

Lauren Busby Ahsler is a structural engineering manager at SunLink. She works on project engineering as well as tracker product development for SunLink.

— Solar Builder magazine

SunLink reports 150 percent growth in total MW shipped in 2017

sunlink racking

SunLink Corp. surpassed more than two gigawatts (GW) of total installed solar projects by the end of 2017. With more than 150 percent year-over-year growth in total megawatts shipped, SunLink increased its fixed-tilt market share by over 4x amid an overall industry decline in the utility ground mount market. The company grew TechTrack, its most technologically advanced solution, by 5x.

“SunLink continued to demonstrate its engineering prowess by taking on some of the industry’s most challenging solar projects in 2017. Customers continued to depend on SunLink to deliver the industry’s most flexible and dependable fixed-tilt mounting solution backed by our deep engineering expertise,” said Michael Maulick, president and CEO of SunLink. “We are especially pleased with the continued traction we’re making in the tracker market. It’s clear that our most innovative customers are responding positively to our intelligent tracker for optimal power density, energy generation and measurable reductions in total project costs.”

During 2017, SunLink’s GeoPro showed significant gains in new geographic markets. SunLink recorded 2,400 percent growth in fixed-tilt projects installed in the Midwest, stimulated by large project deployments in high-growth solar states such as Minnesota. Projects in the Southeast region also grew by 142 percent with local utilities expanding their clean energy mix in states such as Florida and Georgia. The Southeast was particularly challenging last year due to numerous hurricanes, high winds and other environmental factors that made GeoPro the go-to solution.

SB Buzz Podcast: SunLink VP on tech, data, diversity and the path forward for solar

Engineered to withstand high wind speeds of more than 150 mph, SunLink’s GeoPro installations weathered the most challenging environmental conditions this past hurricane season in high impact areas such as Florida.

On the tracker front, SunLink’s TechTrack continued to make strides with a five-fold increase in installations over the previous year. In 2017, select sites had the capability to monitor and control tracker performance via Vertex, SunLink’s tracker intelligence platform, providing real-time smart data captured by IoT sensors. For the first time, SunLink was able to show geospatial tracker performance data at the granularity of an individual row.

What’s coming in 2018

In 2018, SunLink will continue to focus on implementing the latest cloud and IoT technologies to make increasingly more intelligent trackers. New features focused on providing additional data analytics as well as firmware improvements to enable data capture from various sources will provide customers with even greater ability to maximize energy production while lowering installation, O&M costs and return-on-investment.

— Solar Builder magazine