Bifacial Gains: How much will bifacial modules add to solar tracker value? We are about to find out

Soltec

Soltec is testing for all bifacial tracking variables at its new evaluation center in Livermore, Calif.

We are on the verge of the bifacial solar tracker era. Projects are being quoted with many starting to break ground later this year and early 2019.

Only two issues remain in the way of serious wide-spread adoption. First is the price of bifacial modules, which sits at about 30 cents a watt on average right now. The premium price makes sense because the market hasn’t formed yet, and it won’t form until there are bankable production estimates for the technology. That would be issue No. 2: the data set for bifacial tracker performance is incomplete, but this is about to change in a hurry.

Several big-time partnerships between tracker companies, module companies and PV research and testing labs have formed within the last year to understand this new bifacial module + PV tracker paradigm, test theories and build a complete data set on bifacial tracker production.

“This is a fundamentally different paradigm than before because the tracker and module are all intertwined with the site conditions in a way they weren’t before,” says Ron Corio, founder and CIO of Array Technologies.

Multiple approaches

The splashiest of these partnerships is Spain-based single-axis tracking supplier Soltec teaming with the National Renewable Energy Labs (NREL), Black and Veatch and RETC to build BiTEC, the world’s first evaluation center specialized in bifacial trackers, in Livermore, Calif. We visited the facility in July, and the site has a variety of configurations structured to isolate and measure any site or system design effect, such as:

  • Albedo
  • Terrain surface
  • Types of bifacial technology (from Hanwha-QCells, Jinko, Canadian Solar, LG and more)
  • GCR
  • Pitch
  • String design
  • 2x modules in portrait versus 1x.

One variable not changed throughout the field is tracker height, with all 2x configurations standing at 7.71 ft (with 1x configuration trackers at a height of 4.43 ft). The reason is Soltec’s preliminary electric performance measures over bifacial modules reveal a short-circuit current difference of over 2.3 percent between 1x and 2x trackers, meaning that height has a significant influence over the energy output of bifacial panels. The capture of diffuse irradiance below and around the tracker is increased with height, while the shadow cast on the ground is softened.

Array Technologies is taking a different approach. Also working with a U.S. national laboratory, Array is mapping the backside irradiance at a half cell resolution as well as testing various configurations at string level. Array’s testing is focused primarily on the module tracker interaction, varying module mounting techniques as well as testing module design variance. An important objective of this testing is to validate ray tracing simulation programs which will aid in the accurate modeling of bifacial performance in site-specific applications.

“We are working closely with the module manufacturers in a way we’ve never done before for exactly that reason,” Corio says. “When you design the module and the tracker as one system, you get a better result.”

In a comparative one year test, conducted in 2017, Array saw a 9 to 10 percent yearly gain for bifacial over monofacial at the same test site.

Array Technologies

Array Technologies already sees a 9 to 10 percent gain in bifacial tracking performance.

The difference in Soltec and Array’s testing approaches is in line with the difference in their tracking approaches — Soltec uses distributed tracker rows and Array supplys centralized drive. All of the performance gains reported will need to be considered within the already established LCOE of each tracker design.

Example: The torque tube impact is an early point of differentiation depending on who you ask. The Soltec testing team has seen the shadow from the torque tube in a 1x configuration hurting irradiance harvest in a way it does not when positioned in a 2x configuration, so its SF7 tracker includes an intentional gap between modules at the torque tube location that avoids shadowing on the backside of the module. Preliminary measurements have shown that up to 38 percent of reflected light does not reach the center of the bifacial modules compared to the edge due to the torque tube shadow of the 1x configuration. Array is quantifying the impact of the torque tube to harvestable rear side irradiance and testing modules with design characteristics that may use the torque tube as a performance advantage. All of Array’s test data will be compiled in an LCOE comparison.

The difference in testing isn’t really the point. The Lawrence Berkley National Lab noted during the Market Trends panel at Intersolar that the cost premium associated with tracker projects is all but gone with 79 percent of newly installed capacity being trackers. When all of this testing is done, the choice will still be the same centralized or distributed tracker decision its always been, just with these new bifacial performance gains to plug into the equation.

— Solar Builder magazine

Meet the Plug-N-Play Solar Tracker from RPCS, in partnership with Array Technologies, Shoals, CAB Solar

CAB With String Inverter edited

RP Construction Services Inc. (RPCS) has formed a new partnership with solar balance of systems leader Shoals Technologies and CAB Solar to launch the Plug-N-Play Solar Tracker system. This turnkey system features the Array Technologies DuraTrack HZ v3 single-axis tracker, Shoals Technologies’ electric balance of systems wiring solutions, and CAB Solar’s above ground, messenger wire cable management system.

RPCS says this new partnership aims to simplify tracker project install by reducing trenching by 50 percent, utilizing less specialized labor, and requiring less time—all resulting in faster time to completion and CAPex savings. Shoal’s patented pre-labeled wiring systems are key here, and coupled with RPCS’s established reputation for turnkey success, this new system will eliminate the need for trenching within the array, reduce risk and complications associated with cost, lessen environmental influence, and improve trade coordination, creating faster, simpler installations.

What’s more, the Plug-N-Play Tracker approach also allows for more solar panels per string and fewer combiner boxes per site, cutting cost and solar electrical complications.

CAB With String Inverter 3 edited

“We’re really excited to be working with Shoals on our projects,” says Alex Smith, RPCS Chief Sales Officer. “RPCS is constantly striving to make project management easier and to allow our customers to win more projects and trust that the RPCS portion will be executed cleanly. Shoals wiring allows us to do that, as do Array trackers. We can provide a faster installation, a better price, and completely reliable products and project schedules that make executing tracker projects as easy or easier than fixed tilt.”

CAB Solar, the Cambria County Association for the Blind and Handicapped’s solar products division, pioneered the use of above ground cable management in grid-scale solar plants and has continually provided innovative designs and systems to meet customers’ needs. The newly released Integrated Grounding Cable Management System uses a copper composite messenger wire and specialized hardware for grounding and is safety listed by Intertek to UL 2703. For over 85 years, their various products routinely exceed the most stringent quality standards demanded by respected national and international customers.

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

“CAB systems integrate well with both Array and Shoals, and RPCS is very knowledgeable in how to maximize CAB’s benefits. We are excited about the potential,” says Tim Wedding, CAB Solar Project Manager.

With over 400 MW and over 225 projects completed throughout the United States, RPCS provides full turnkey service and support for the industry’s most bankable and reliable tracker. The team at RPCS provides reliable support at every step of the project, delivering a level of quality and efficiency that parallels Array’s market reputation.

CAB Solar RPCS

“We are excited to partner with RPCS and are glad to support the highly optimized approach to solar construction that RPCS is taking by integrating a great family of products,” says Kent Miller, Shoals Technologies Senior Vice President of Sales, of the Plug-N-Play Tracker. “Combining above-ground wire management from CAB Solar Products, the Array Technologies tracker, and the Shoals wire management system is going to help developers and EPCs by providing a schedule-friendly and easier-to-maintain system.”

“As an electrical guy at the core, there is nothing better than a wireway that is accessible. RPCS’s installation, in combination with the Shoals wiring system, Array’s solar trackers, and the CAB Solar hangars, the installation process is smooth and keeps wires away from unknown underground conditions,” says Adam Larner, RPCS’s Vice President of Projects.

Through this latest offering, RPCS will be a single point of contact for design, engineering, installation, and procurement. From factory floor to field installation, RPCS makes tracker projects even simpler with the Plug-N-Play Tracker. Together, RPCS, Shoals, Array, and CAB provide customers the next evolution in solar tracker systems, making solar energy a more affordable, lower risk source of clean power for future generations.

— Solar Builder magazine

sPower renews partnership with Array Technologies for the next three years

Array+sPower

Array Technologies and sPower announced a three-year partnership at the GTM Solar Summit in southern California to do multi-gigawatts of business. This announcement comes after the two big brands’ previous four years working together.

“The newly created partnership between Array Technologies and sPower is a testament to the strength and success of a matured-U.S. solar market,” said Jeff Krantz, Senior Vice President at Array Technologies, “This deal represents a significant milestone for our company’s continued robust growth throughout the nation.”

The adoption of solar trackers for utility-scale solar projects has grown significantly in recent years, with more than 70 percent of ground-mounted PV systems in the United States utilizing the technology. In regions with high solar irradiance, trackers can produce a 20 to 30 percent increase in energy output over fixed-tilt systems. The continued adoption of solar trackers comes down to economics and reliability.

“We are looking forward to this partnership with Array Technologies – it’s going to help enhance our solar portfolio for years to come,” said Josh Skogen, Senior Vice President of Project Development at sPower.

“Studies have shown Array’s patented technology to provide the lowest O&M costs of the different architectures on the market, so the partnership is not only a positive industry collaboration, but also provides a significant financial benefit to sPower as the owners of these assets,” said Krantz.

— Solar Builder magazine

RPCS completes 11 new solar tracker projects in Texas

RP construction services

RP Construction Services (RPCS) just completed 11 solar sites as part of a growing portfolio of projects in Texas for the Pedernales Electric Cooperative. RPCS, responsible for the portfolio’s solar tracker installation, partnered with site developer and global energy firm Renewable Energy Systems (RES) and general contractor Performance Contracting, Inc.

The 11 projects rely on the DuraTrack HZ v3 single axis tracker from Array Technologies. This technology keeps the modules following the sun on its course throughout the day, ensuring up to a 20 to 25 percent increase in energy production over fixed-tilt systems. The sites also feature rigid thin-film solar panels from First Solar, an American photovoltaic manufacturer and provider of utility-scale power solutions. RPCS, Array Technologies’ DG partner, designs and installs single axis solar tracker systems across the country, with hundreds of projects to date in the utility and distributed generation markets.

“We love working for the RES team and are very proud of these projects,” says RPCS Chief Sales Officer Alex Smith. “Having 11 projects underway at one time is one of the things that RPCS does best for portfolio companies, and we are really excited to see all the First Solar panels on top of ATI trackers. It’s the best combination of price and speed of installation, which has al-lowed us to execute these projects so cleanly. The sites turned out beautifully and we’re thrilled for the opportunity to work together with RES and PCI.”

The portfolio of projects utilized decommissioned agricultural land leased from local land owners and was flexibly designed to minimize environmental impacts by requiring no major grading. RPCS trained dozens of Texas locals on the installation over the course of the projects, working alongside the local electricians and general contractor labor. The projects have all been injury-free.

Wes Allen, RPCS Superintendent, says, “We had a lot of fun training the local labor. They under-stood what it meant and what it took to build a quality tracker for the community. Because of the quality of work, we requested some of them travel with us to complete the portfolio in oth-er parts of Texas. I received a lot of positive feedback from the locals, and they really enjoyed working with RPCS and can’t wait to build another project.”

— Solar Builder magazine

Report by TÜV Rheinland explains how Array Technologies trackers drive O&M costs down 37 percent

Array Technologies announced results of an independent analysis by TÜV Rheinland that indicates Array’s flagship tracker, the DuraTrack HZ v3, delivers 4 Cents/Watt DC higher Net Present Value (NPV) and 6.7 percent lower Levelized Cost of Energy (LCOE), driven by 37 percent lower lifetime O&M costs.

Array Technologies DuraTrack

The analysis found that Array’s architecture has higher structural integrity. With a patented mechanical load-release system, Array’s trackers are less susceptible to torsional galloping and consequential damage to solar modules. The DuraTrack HZ v3 withstands high wind loads in all positions, unlike architectures that rely on active stow and a complicated chain of electronic, radio, and motor systems to survive.

TÜV analysts performed an economic and risk analysis of two tracker architectures: one driven by a single motor linked by a rotating driveline to multiple tracker rows; and another where tracker rows operate as self-contained units, each with a dedicated photovoltaic (PV) panel, battery, motor and other system components. TÜV’s analysis includes descriptions of the technical characteristics of each system, followed by a Failure Modes and Effects Analysis (FMEA) to determine high-risk components. A cost of failure analysis of those components was performed, concluding with a LCOE / NPV analysis to assess the economic impact of the two technologies on developers, owners, financiers, and insurers of utility scale solar power plants.

“Reliability is the cornerstone of responsible solar industry growth,” said Array Technologies CEO and founder, Ron Corio. “Without dependable PV modules and tracking systems, the solar industry will struggle to continue down its path of innovation and expansion. This third-party validation from TÜV confirms what we have been claiming for nearly 30 years: that the engineered simplicity in our trackers truly is the best long-term option for solar project owners.”

— Solar Builder magazine