NEXTracker working on a giant 325 MW solar tracker project in Egypt

solar tracker NEXTracker egypt

Global solar EPC company Sterling and Wilson selected NEXTracker to supply 325 megawatts (5 blocks of 65 MW each) of its smart solar trackers to its massive project within the Benban solar park in Aswan, Egypt. The Benban solar park occupies 37-square-kilometers and, when completed in 2019, will host a total capacity of more than 1.6 gigawatts (GW), making it the largest planned solar installation in the world.

Egypt is increasingly turning to the sun for power as solar has become competitive with traditional generation. The World Bank reports that Egypt relied on fossil fuels for 96 percent of its total energy consumption in 2014. Looking forward, Bloomberg New Energy Finance reports, “Egypt plans to generate 20 percent of its electricity from renewables by 2022.”

“We’re thrilled that Sterling and Wilson chose NEXTracker to supply our trackers for what’s predicted to be the largest solar facility in the world,” said Dan Shugar, founder and CEO at NEXTracker. “We’ve developed a successful partnership with Sterling and Wilson, having deployed over 400 MW of trackers for their projects in India, and are delighted to be extending that partnership to North Africa. It’s very gratifying to be a part of Egypt’s investment in the solar industry and the country’s movement towards a cleaner and brighter future.”

Four trends leading ground-mounted solar in 2018 from IHS Markit

 

— Solar Builder magazine

Get to know NEXTracker’s Energy Storage Solutions offering

NEXTracker

Bloomberg New Energy Finance forecasts the global energy storage market will “double six times” by 2030, growing from less than 5 gigawatt-hours in 2016 to more than 300 gigawatt-hours. An estimated $103 billion will be invested in energy storage over that time period. All of those numbers mean a big opportunity for solar, which is why NEXTracker is broadening its approach to large-scale PV deployment by adding an Energy Storage Solutions portfolio of products alongside its decentralized tracker system.

The storage solutions include NX Drive, a standardized battery enclosure system for generation-plus-storage or stand-alone storage applications, and NX Flow, a modular, integrated solution designed for long duration solar-plus-storage applications. Each is designed to maximize long-term value and offer the lowest levelized cost of storage (LCOS) for a wide variety of applications, such as peak smoothing, bulk load shifting and demand charge reduction.

Inside NX Drive

NX Drive provides a flexible, pre-engineered balance-of-system (BOS) solution for virtually any generation-plus-storage or stand-alone storage application. NX Drive consists of a standard ISO form factor enclosure with pre-engineered and integrated electrical, mechanical, and thermal management features. Customers can also upgrade battery modules as technology continues to evolve and integrate PV and/or storage inverters depending on design preference. Using advanced, patent-pending technologies to ensure safe operation and optimized performance, the container delivers a standardized system infrastructure for customer-supplied or NEXTracker-procured Tier 1 lithium-ion batteries.

Inside NX Flow

NX Flow’s complete storage solution (formerly known as NX Fusion Plus) integrates battery, inverter, solar tracker and software technologies to improve return on investment for owners of solar power plants. At the core of the system lies an advanced vanadium flow battery (VFB), which is DC-coupled with the photovoltaic (PV) array for high round-trip efficiency. With NX Flow, the battery charges directly off the array, enabling the battery to capture “clipped” energy up to its storage capacity limit. Energy that has been lost to clipping can now be captured and used to generate additional kilowatt-hours revenue. Pairing NX Flow VFB technology with ground-mounted solar power offers a bankable long duration storage option for project developers and asset owners.

— Solar Builder magazine

Case study: Prepping solar tracker systems in advance of a hurricane

Flood clearance_Virginia_Hurricane Matthew Oct2016_2 - Copy

When the U.S. government declared a state of emergency in advance of Hurricane Irma’s arrival on Sept. 8, we knew what was at stake for the 33 NEXTracker solar projects (or 24,000 tracker rows) that would be affected by the impending high winds and flood waters. Although our experience with the destructive winds and torrential rains of Hurricane Matthew in 2016 gave us full confidence that our systems would stand up to Irma’s fury, our NX services team nevertheless sprang into action to ensure our customers were fully prepared.

Monitoring Irma’s strength and direction, the NEXTracker services team contacted all our affected customers in the projected path of the storm in Florida, Georgia and South Carolina. One of those customers, GroSolar, had installed approximately 50 MW of NEXTracker NX Horizon systems, some of which were likely to be impacted by Irma. Tom Lyman, GroSolar’s director of project management, was apprehensive. There was good reason for his concern. From a technical standpoint, unlike thunderstorms or synoptic winds, hurricanes are large, cyclonic events subject to radical changes in wind direction and speed, depending on the location and trajectory of the storm.

For GroSolar and the other customers in Irma’s path, we leveraged our Digital O&M remote monitoring and control capabilities to ensure that each of several thousand tracker rows were appropriately buttoned down for the storm. Thanks to inclinometers on every tracker row, NEXTracker was able to remotely confirm that each tracker had been stowed to the safest angular position ahead of the brunt of the storm. We also placed local field service teams on high standby alert to be ready for any contingencies.

Details on new solar fixed tilt, tracker Pro packages from SunLink

With the trackers secured against wind, attention turned toward potential flood impacts. NEXTracker systems are inherently optimized for flood conditions, with all drive and control components located high above ground level. “Once we visually confirmed that all was secure, and electricals were out of possible flood zones, I felt much better,” Tom told me later. “With the proper positioning of the trackers and the ongoing attention from the NEXTracker service team, we weathered the storm with no damage to those systems whatsoever.”

Once the storm passed and the grid came back online, the GroSolar solar farms quickly resumed power generation. Our team at NEXTracker’s Remote Operations Center (ROC) verified that all trackers had returned to their normal operating mode with no damage or performance issues, and concluded that no service personnel needed to be dispatched to perform visual inspections at the sites.

In Irma’s case, there was less flooding, but had there been, we were confident in NX Horizon’s survival, as our affected systems came through 2016’s Hurricane Matthew with zero damage. With Matthew, the NEXTracker sites in Virginia and North Carolina were unharmed by the high winds, and none of the drive and electrical components came into contact with rising waters due to the aforementioned ground clearance.

Marty Rogers is SVP of Asset Management and Global Services with NEXTracker. This was originally posted on the NEXTracker blog.

— Solar Builder magazine

Solar tracking system advances: What’s the impact over the life of a PV plant?

Solar tracker photo 1

The goal of a solar tracking system is to boost the lifetime energy production of a given site, somewhere between 20 to 30 percent over a 30-year period. But this is not a “set-it-and-forget-it” proposition. Today’s tracker systems are more advanced than ever before, but they require an operations and maintenance (O&M) plan that’s just as sophisticated, if not more.

“The performance analytics of a site will become increasingly defined by O&M activities over a longer time span, as costs associated with system failure and maintenance, labor and transport are compounded,” says Denise Hugo, director of marketing with Array Technologies Inc.

If your O&M planning starts after the project is in the ground, which can happen with today’s time pressures, it is already too late. Reliable PV tracker performance starts with specing and designing the right system to match the project.

Intelligent Design

A system is only as good as its ability to exist in its environment. Beyond the obvious structural necessities required of any mounting system, tracking functionality can both improve and further complicate the plan for withstanding the elements. Some improvements are simple, like tilting opposite rows toward each other to clean two dusty rows in one pass. Others come from the sophistication of the software.

“We have seen a trend toward greater reliability in the face of the increasing intensity and frequency of weather events,” Hugo says. Array, for example, incorporated a torsion limiter in its centralized DuraTrack HZ v3, which naturally improves the stability of the system during wind events.

Array Technologies DuraTrack

“When a heavy wind occurs and wind speeds approach record highs, tracking systems can risk catastrophic failure. The best rule of thumb is to design the tracker system to withstand the full site specified wind speeds at any tilt angle, instead of relying on risky stow strategies.”

Separate UPS [uninterruptible power supply] systems proved to be problematic in early tracking days, which inspired tracker manufacturers to integrate backup power into the trackers themselves or eliminate the need for backup power entirely.

Whether a site’s climate patterns evolve over time, or experience a sudden aberrational event, tracking systems can adjust. SunLink says meteorological stations are integral to intelligent tracking systems.

“The data from these stations can be used to meet ongoing financing and operational requirements,” says Kate Trono, VP of products at SunLink.

More Motors or More Maintenance?

But as my cranky mechanic dad would say when car manufacturers would improve anything (like, going from crank windows to power windows), more sophistication can also mean “more stuff that’s going to break.” Trackers need motors and power sources, which introduce additional points of failure. The answer from tracker manufacturers is to minimize as many of those variables as possible, but which variables specifically depends on the approach of the manufacturer.

Array, a leading supplier of centralized drive tracker systems, believes in minimizing the number of motors and other high-maintenance parts that are needed as well as drawing power from the grid instead of relying on batteries.

“We use the minimum amount of electrical components required for control at each motor,” Hugo says. “Simply put, less moving parts make for fewer problems. By removing the number of smaller, less reliable motorized components and condensing this into a flexibly linked centralized single-axis tracker architecture, we have significantly improved uptime and dramatically lowered O&M costs.”

Movement is also taxing on all of a system’s components, and maintaining hardware is tedious and costly. Some tracker systems may require crews to regularly check the torque on screws or lubricate joints, which can add thousands of hours to an annual O&M budget. NEXTracker, currently the market share leader in global tracker deployments according to GTM Research, says a key in minimizing maintenance needs here is valuing mechanical tension over torqueing.

“Torqueing is by nature inexact because of the many factors that can affect friction — from surface texture to debris, rust and humidity,” says Dan Shugar, CEO of NEXTracker. “By contrast, tension involves the use of hydraulic tools to stretch screws and swage or fasten bolts to a structure. In fact, the swaging of a lockbolt is five times stronger than its nut-and-bolt counterpart fastening system. Regular nuts and bolts have a gap, which can cause loosening by vibration. System hardware that does not require torqueing but instead relies on the tension between components will reduce the need for manual checks.”

Shugar believes the key question to ask when evaluating single-axis trackers is this: Could the failure of any individual hardware component threaten the system’s overall production?

“In the case of a decentralized SAT, for example, each row’s independent motor is powered by its own dedicated solar panel (with integrated battery backup), making external power cables obsolete. This reduces the risk of asset downtime since each row is essentially its own independent system. Having advanced individual, self-powered motors control each row increases the overall resiliency of the solar plant by eliminating the risk of malfunctions that can lead to downtime for a larger portion of the installed capacity.”

Trono says decentralized trackers have gained momentum because they are actually simpler to maintain. Downtime is also minimized by holding spares, which is made possible by highly modular systems.

“No special tools or expertise is required to swap out a motor, for example, and it’s not necessary to take an entire linked-row tracker offline,” she says.

Distributed trackers also streamline engineering between the EPC and the mounting system provider, which can result in meaningful savings in soft costs.

“Consider how self-powered, wireless systems eliminate the back and forth and inevitable drawing revisions concerning connection points, conduit, etc. to each tracker,” Trono says. “Furthermore, since each tracker row is independent, they’re easy to add and remove from a layout. Changes to inverter locations and access roads stay simple rather than cascading through the layout departments of multiple companies.”

“The appropriate tracker choice, one with robust components and minimized failure points, will guarantee the best performance over time,” Hugo says. “With the increased efficiency of other BOS components, such as the inverters, highly reliable tracked projects can actually incur less total O&M costs compared to fixed-tilt.”

Data is the future

While my dad had a point — that new advances in technology create new issues — what he didn’t see was the extended benefits of improved performance. This is where data changes the game in O&M and the lifetime value of a tracking system. Smart devices and the Internet of Things means even the largest solar plants can be monitored down to the component level.

“Data is essential to deploying O&M resources efficiently,” Trono says. “Row-level tracker intelligence complements other data systems to give a complete picture of system performance.”

SunLink

There are always outlier incidents that require immediate analysis to determine if action is required. Having access to minute-by-minute tracker performance data helps system owners and their O&M partners understand when and where to place maintenance resources to manage assets effectively while keeping down LCOE. The correct course of action, though, can only come from setting up a software and O&M strategy that interprets the data correctly.

“The data that this constant monitoring produces can become overwhelming for system owners,” Shugar says. “To understand the true implications of system issues, an intelligent cloud-based O&M strategy must be developed that weighs the cost of truck rolls against possible impacts to system performance and the value of the energy produced. Just collecting data doesn’t reduce O&M costs. It’s how intelligent tracking systems and asset managers use that data that reduces truck rolls and increases long-term ROI.”

And this is the note to end on because the biggest strides to be made in solar tracker O&M going forward will be made in data and control.

“As an industry, we’ve only scratched the surface when it comes to harnessing the power of integrated data and control systems,” Trono says. “Unfortunately, many data systems are siloed because of security concerns or integration challenges. In the future, we will see advanced control systems that can be used to improve the performance and future product design of both tracking and fixed-tilt systems.”

Chris Crowell is managing editor of Solar Builder.


Tracker System Profiles

DuraTrack HZ v3DuraTrack HZ v3

Array Technologies’ tracker architecture is designed to withstand the elements, not to stow. Unlike trackers that rely on active stow to attempt to survive inclement weather, the DuraTrack HZ v3 is designed to reliably handle the full site loads at any tracker angle. Array’s tracker incorporates a mechanical load mitigation system based on a unique torsion limiter gear and redundant mechanical stops. The system is automatic and doesn’t require power backup, wiring, anemometers, controllers or regularly scheduled maintenance to function, which eliminates backup systems, potential failure points and a ton of maintenance.

How does it save time and cost?

Array Technologies’ trackers are designed to deliver the lowest cost of ownership and the highest value, forged from decades of experience. DuraTrack HZ v3’s streamlined design lowers installation and O&M costs. It is built with minimal failure points and zero scheduled maintenance over a 30-year lifespan.

NX Horizon

NX Horizon

Powered by NEXTracker’s self-powered motor drive, each row of the NX Horizon system can now be built with significantly less steel and can be optimized for wider rotation angles. As a result, customers will maximize yield, pay less for O&M and reduce the impact on the environment significantly. NEXTracker designed a mechanically balanced system that has no overturning moment at the core of the NX Horizon tracker. This allows NEXTracker to bring down the number of piers needed for one row of solar panels by up to one third.

How does it save time and cost?

NEXTracker’s NX Horizon tracker needs less steel than conventional trackers, allowing for quicker installation. Customers won’t need drive shafts or extra cabling to power the trackers, speeding the process up even further. NX Horizon is self-grounded, so customers won’t have to pay costs and labor for installing grounding washers, braided straps, bare copper wire and grounding rods. Zero welding is required. NEXTracker’s patented fasteners make mounting the panels quick and easy.

TechTrack DistributedTechTrack Distributed

One of the most popular features of SunLink’s TechTrack Distributed is the balanced row bearing design or “virtual pivot.” The bearings arrive at the jobsite preassembled, and the installation team can quickly and easily bolt the assemblies to the top of the posts. The bearings then form a cradle in which to rest the torque tubes — the heaviest component in the system — during their installation. Plus, at every stage of racking assembly and module installation, the system remains balanced, eliminating the need to take precautions to restrain it from swinging. The most innovative feature of the TechTrack is Dynamic Stabilization. The design utilizes an active, sensor-enabled component to change the damping and stiffness of the structure in response to real-time environmental conditions. This dynamic design dramatically enhances load management and reduces required steel.

How does it save time and cost?

TechTrack Distributed has no gaps at the bearings or splices, which can add up to several feet on each tracker. Instead it enables clean, continuous tables of 90 modules with one small gap at each slew drive. TechTrack Distributed packs more power into a given area, maximizing the potential of the site. In addition to generous installation tolerances and the flexibility of unlinked rows, TechTrack Distributed is designed to contour with North-South changes in grade of up to 2 percent post-to-post. For example, on a site that would have required extensive grading or very long and heavy posts to keep the array flat, TechTrack has enough flexibility built in to eliminate those costs.

— Solar Builder magazine

NEXTracker’s newest solar tracker control system self-adjusts in real time

NEXTracker is launching a new, intelligent self-adjusting tracker control system for solar power plants that it’s calling TrueCapture. The technology will continuously refine the tracking algorithm of each individual solar array in response to existing site and weather conditions. Typically delivering 2-6 percent energy gains, TrueCapture enables system owners and developers to maximize solar system performance and enhance profits for solar power facilities.

How it works

California grower solar

Solar power plants suffer energy production losses from construction variability, terrain undulation and changing weather. TrueCapture will simultaneously solve these factors, leveraging forecast-based tracking behavior algorithms for clouds, fog or haze and row-to-row (R2R) hybrid closed-loop self-learning that course corrects the panel direction to minimize production loss due to shading and clouds. Wireless self-powered controllers on the tracker sync with the smart panels and the NEXTracker SCADA (supervisory control and data acquisition) system, connected through Flex’s IoT platform, a secure, NERC-CIP compliant, industrial-strength connected intelligence platform. From the Flex IoT platform, communication is continually dispatched to control each independent row.

With TrueCapture, proprietary smart panel sensors provide real-time shading information on each tracker row. The data is integrated with design parameters and processed by machine-learning software to build a virtual 3D model of the job site. An intelligent control engine combines the model with the latest meteorological forecast data to calculate and send updated and optimized tracking commands to every independent row. As a result, energy production gets a significant boost. With more production, solar power plants are worth more, adding value for project developers and the long-term owners who will typically operate a facility for up to 30 years.

— Solar Builder magazine