Manufacturer Perspectives on Array Tracking Markets, Equipment and Innovation
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According to GTM Research, “By the end of 2017, 23 percent of ground-mount PV systems globally will use trackers, with that number expected to grow to 44 percent by 2022.” In addition, it reported that solar projects in the US accounted for 70% of worldwide array-tracking system deployments in 2016. In the US and at the utility scale, the ongoing market shift from fixed open-field arrays to tracked ones is well documented and linked to driving project-site characteristics, including location and irradiance values.
Vendors of array tracking solutions for utility-scale projects have a diverse makeup. Some are pure-play vendors that have focused on tracking technology for decades. Others are manufacturers of fixed-tilt racking solutions that have expanded their product lines to include tracking solutions.
For this article, I interviewed team members from five different vendors. Each vendor has a unique history, market perspective and tracking technology in what has become one of the PV industry’s most interesting and exciting areas of growth, both in the US and beyond.
Ron Corio, founder and CEO, Array Technologies, arraytechinc.com
JS: Array Technologies has a long history in the solar industry. Can you run us through its business and product development timeline?
RC: Basically, we started in 1985. We were building concentrator PV modules, and I developed a tracker for the modules. We never commercialized the module, but we did start selling trackers to the remote home market. The real kickoff for the company (then called Wattsun Corporation) was when Home Power magazine bought a tracker—tracker number three. Home Power’s publisher, Richard Perez, wrote a positive review, and that kick started our off-grid home tracker marketing. We probably shipped about 20,000 of those trackers over the years to all kinds of places: the Arctic Circle, Fiji, you name it.
Simultaneously, we always had our eye on utility-scale trackers. We did our first utility-scale project in 2002. It was a 250 kW horizontal single-axis tracker project with BP Solar in Davis, California. It had an individually motorized row system with an offset center of gravity. We also sold some of those trackers in Korea and in Spain. In 2007, we developed our first linked tracker system in Alamosa, Colorado. It was the largest utility-scale solar plant in the US at that time—7.2 MW. That project has almost 11 years on it now. It’s operationally spectacular. There have been maybe three repairs on the tracker system since installation.
At the time, the big news was in Spain, where a lot of companies installed dual-axis trackers because of artificial economics that were driving the market, such as high feed-in tariffs. But the reliability of those things was horrible, which created a lot of resistance to trackers in the US. Everybody believes if it moves, it breaks. What we really had to sell was reliability.
We developed a system that could follow terrain, that wasn’t rigid and that was material efficient. It’s based on the rotating driveline linked-gear design that we came up with for the Alamosa project. It just took off. We called it DuraTrack because durability was the focus, and we had to do a lot of justification for the lifetime of the equipment. The banks were nervous. They saw what happened in Spain, so we had to go through failure mode effects analysis. I had to get scientific about defining the term lifetime, because without good design all kinds of failures can occur.
JS: Array Technologies’ DuraTrack product has been through a few versions at this point. What are some technical highlights of the DuraTrack HZ version 3, and what did your team learn from the various design iterations?
RC: Version 3 came out about 2 years ago, and that was a step forward for us. We had done about 3 GW of projects. We had 250, maybe 300 utility-scale projects under our belt. We had learned a lot and we aggregated enhancements—to installation, to metal use, even to functionality in terms of wind events—into version 3. We’ve differentiated how we deal with the wind. Most tracker manufacturers thin out the metal in the structure and design around a stow-flat or stow-at-a-shallow-angle strategy. The nice thing about our system—and one of the tenets that I instill in the engineering team—is that it’s all about minimization of materials through intense integration of function. Everything has to do as much as it can. When you’re considering square miles of tracked arrays, every small item matters.
Another big innovation in version 3 is its torsion release system. When the wind blows, the outer rows of an array field receive more pressure than the internal rows. Typically, at about a 60-mph wind, the tracker row will move into a less torsioned position. Usually that means it will get more vertical, which is counterintuitive. But what it really does is act as a safety valve for harmonics in the system. You have a very long row of about 300 feet and 90 modules. It’s flexible, and at the center there’s a kind of spring effect because you have a torque tube. Resonant harmonics and torsional galloping can occur. When you have the safety valve in there, it relieves the harmonics and actually minimizes the torsion in the torque tube, which allows you to have larger spans and fewer foundations. Our new design links almost a megawatt—about two football fields of arrays—with one motor. From a maintenance standpoint, we use a very high-quality German industrial-grade motor that should last the life of the PV modules.
When you look at the tracker space today, there’s push-pull, which is a heavily weighted rigid system requiring level terrain and often a lot of earthwork. An independent row tracker is flexible—you can put it wherever a row can fit properly. We like to think of our solution as the best of both worlds because it has one motor that drives 30 plus rows, and it follows terrain. It’s flexible and yet efficient, and it minimizes failure points and components.
JS: There was a time when module prices were falling so rapidly that one possibility was a negative impact on the tracker market. What actually happened was the exact opposite.
RC: When people tell me that modules are going to get so cheap, we’re not going to put them on a tracker, I say that’s absolutely the wrong conclusion, because modules get cheap through efficiency increases. The price of a module today is pretty close to the cost of its components’ processing. It costs the same to track a module that produces 300 W as it does to track a module that produces 370 W. As that module gets more efficient, the cost to track per watt goes down. The other piece is that as we get smarter about tracking, we get more material efficient and better at manufacturing, which also drives the price of tracking down.
Then there’s economics. You spend 7%–10% more for a tracker on a project, but you gain maybe 20% in generation. That alone is a big economic gain. The more PV we put on the grid, the more we want to flatten the output from this array. With a tracker, you broaden the production profile early in the morning and later in the day, when peak power is at a premium. If you look at coupling tracking with storage, trackers allow you to use less storage because they push that power out later in the day. You get an overall economic benefit in terms of production versus cost, and you get the power in a more level fashion that’s in tune with when the utility wants it. In addition, it drives down storage capacity requirements. The economics of tracking are favorable, and the market has borne that out. Over 70% of utility power plants in the US are on trackers.
Internationally the scene is interesting. Different markets have different maturity levels, but we’re seeing quick adoption of trackers, and some markets just start with trackers. We’re doing a lot of business in Australia these days. Obviously it’s geographically dependent. If you’re up in the Northeast, maybe the gain doesn’t justify the cost, so you may go with fixed. We’re doing tons of business in the Southeast. It doesn’t have to be blazing sun; it just has to be decent for the economics to pencil out.
JS: Did you ever imagine the solar industry would grow and evolve this quickly?
RC: I always believed in solar. I had an idealistic mind about it early on, but it just seemed like the right approach. One thing I realized over all these years is that the real driver is always economics. I’m glad we’re at the point as an industry when we can offer an economic renewable solution to energy. That’s really the accomplishment this industry has attained in a remarkably short period of time.
Mike Mehawich, chief marketing officer, NEXTracker, nextracker.com
JS: NEXTracker is a relatively new company with a very long history. Can you run us through its origins and milestones?
MM: Formally founded in late 2013, NEXTracker essentially came out of the EPC side of the solar industry. Dan Shugar, our CEO, founded PowerLight back in the late ’90s. Prior to that, he worked with PG&E. His experience enabled him to bring technology and EPC thinking together at PowerLight, which became a leading installer as well as a developer of new solar technologies. That’s the core DNA of the company.
Dan, most of our executive team and I were also involved with Solaria. That company originally focused on concentrating PV module technology that required tracking. Our work at Solaria gave us an opportunity to assess what was happening in the tracker market. Basically, we found that there hadn’t been a lot of innovation in the tracking space. So we decided to take it all in house and develop our own tracker. We didn’t want to do that. It’s actually not an easy thing to develop a tracker. It may seem like a simple product on the surface; but when it comes to dealing with real-world conditions, the solution needs to last in the field, operate and rotate back and forth every day for 25 or 30 years. It’s quite an undertaking. However, we felt compelled to do it and really took a clean-sheet approach to reimagining what a tracker could look like and how it could work.
We came up with an independent row design and then moved into a self-powered independent row design where each tracker row is truly an independently operating unit that’s running off energy from the sun and not from the grid. As the module industry was getting more challenging due to falling costs and tighter margins, Dan decided that the tracker itself was interesting enough to build a separate business around. Therefore, we executed a spinout from Solaria as the new company NEXTracker. We formalized this in 2013, and saw a very rapid uptake of the technology. What we were doing resonated with our EPC and owner customers, and we started building market share very rapidly. Greentech Media named us the number one global tracker company by market share in 2015 and then again in 2016.
JS: Flex acquired NEXTracker in 2015. Did this partnership have a big impact on NEXTracker’s growth trajectory?
MM: Absolutely. That was certainly one of the rationales for us to entertain the idea of doing that merger. At the time, NEXTracker, despite having great early success with our product, was still considered a start-up. There’s always that class of customers who are not comfortable dealing with a company that’s been around only for a year or two. So it certainly provided us with a step up in terms of bankability. Now all of a sudden, the customer is dealing with a $26 billion company that’s been around for 50 years and has 200,000 employees and operations in 30 countries around the world. The partnership really facilitated our international expansion. Flex had established business operations in a lot of the markets around the world that NEXTracker wanted to enter, and the partnership certainly made things a lot easier for us to do that. We were able to leverage Flex’s existing investments in those countries and just focus on what we do, which is design and sell trackers.
JS: What services does NEXTracker offer its customers?
MM: We definitely take an approach of not just throwing hardware over the fence. We work with our customers every step of the way, from the initial contact with NEXTracker through the commercial operation of their plant. We have up-front design services. We help customers with layouts and estimating the system’s energy yield. We assist with efforts to maximize the density of the trackers on the site based on our experience. After we deliver the hardware to the site, we provide project support services. We’re out there with our customers, making sure that the installation goes off smoothly.
We pioneered a program called Power Works about a year and a half ago, especially for new customers who don’t have experience with NEXTracker. They come to our headquarters in Fremont or one of our satellite offices around the world and receive in-depth installation training and best practice guidelines. Then the customer can train subcontractors and their crews. They’re able to leverage our experience to accelerate their installation philosophy.
JS: NEXTracker’s products seem to go through frequent design iterations and refinements.
MM: Yes, that’s accurate. The major innovation was the self-power concept. NEXTracker was the first company to commercially scale a self-powered horizontal single-axis tracker. We’ve continued to refine the design, making it more efficient and more reliable. What we’re focused on now is pairing software with hardware to create more flexibility and future-proof the platform to an extent.
We’re trying to get away from this mentality of thinking about balance of system components that you install and have to live with for 30 years and to start approaching trackers as equipment that’s dynamic and upgradable over the life of a system. It’s analogous in a lot of ways to how Tesla approaches its vehicles. Tesla treats the vehicle as a platform. When you purchase the vehicle, you get a certain set of features and capabilities; and as Tesla improves its technology, you can upgrade it with the new functionality.
The other high-level shift in the product has been a move toward more-integrative solutions. We’ve stopped thinking of the tracker as a single product and started to think of it as part of a value-added system. The first iteration of that is our NX Fusion Plus, our tracker plus inverter plus battery storage solution. We launched it in December last year.
JS: I’m curious about the decision to integrate with flow rather than lithium-ion technology, at least initially.
MM: Both the applications we’re looking at and the cost structure drove that decision. In pairing NEXTracker with storage, our focus has been on storage duration in the range of 2 to 4 hours. Some initial market opportunities we have access to are demand charge mitigation and load shifting. For these applications in particular, a flow battery is advantageous on a cost basis. More broadly speaking, flow has a lot of intrinsic cost advantages, particularly in terms of degradation. With flow batteries, there’s essentially no degradation for the life of a PV plant, so you’re able to maintain the capacity over time. For our current applications, it’s a more elegant, self-contained, modular solution than containerized lithium solutions, which can be custom projects in and of themselves.
JS: What do you see on the horizon for tracking systems in terms of innovation or markets?
MM: The competition in the industry has definitely increased, and we consider that a good thing. We want other good tracker companies out there providing a positive image for trackers as a general technology to our customers. At the same time, competition drives the need to maintain differentiation and to continue innovating. One area we’re really focused on is improving the performance of tracked array systems. If you can get several percentage points more energy production from your tracker, that value accrues relative to the total installation cost of the system.
In other words, if I’m installing a system for $1 a watt and I’m getting 2% more energy, you can think about the increase as 2 cents a watt of lifetime value, which is a huge number relative to the cost of the tracker. This focus on performance led us to the launch of our TrueCapture feature at Intersolar North America, which our customers received very well. It’s a completely new way to think about the control system of the tracker and builds on what Dan originally worked on back in the ’90s with backtracking—a technique to improve the performance of a tracking system by avoiding shading.
With TrueCapture, we’re dramatically re-envisioning tracker control with advanced machine-learning software technology that enables each individual tracker row to essentially learn and execute a completely unique tracking algorithm relative to every other row. The software takes into account real-world conditions, such as site topography, construction variances and weather conditions at any given time. It integrates all that data and applies machine-learning software techniques to compute unique tracking commands for each row that it then dispatches to the plant in real time. It allows us to optimize the performance at a much more granular level than has ever been done before. Just like we broke the physical link of having tracker rows linked together, now we’re breaking the virtual link by allowing each row to optimize its performance. Based on analysis we’ve done at a real-world site, TrueCapture can drive anywhere from 2% to 6% more energy. That’s huge, especially when you apply that kind of increase across multiple gigawatts.
Steve Daniel, executive vice president of sales and marketing, Solar FlexRack, solarflexrack.com
JS: Solar FlexRack’s product line includes its flagship preassembled, expandable fixed-racking system and, more recently, independent row trackers. Please provide some company and product background.
SD: Solar FlexRack’s parent company is a 44-year-old metals company, Northern States Metals. The company produces aluminum extrusion products. It can manufacture anything from a hubcap to a lighting fixture to products as large as a subway car, which is an aluminum extrusion, believe it or not. It currently makes the electric vehicle charging station structures for ChargePoint.
Northern States Metals first got into the solar business when First Solar contracted it to manufacture module clips for frameless PV laminates. First Solar ordered something like 830,000 clips from a vendor in China, but due to a miscommunication, the vendor manufactured and delivered only 830 clips. One of our salespeople had been calling First Solar, and on this occasion the company said, “Could you build us these clips?” We went back and designed the clips, and we got into the solar industry. We started selling First Solar clips—millions and millions of clips.
Then First Solar came to us and said, “There hasn’t been much innovation in the racking industry. Would you guys look at designing a rack?” We designed a factory-assembled rack that installers unfolded on the jobsite. It was a real innovation and did extremely well. When the solar racking market shifted and went half aluminum and half steel, and then all steel, we developed new products. In the Northeast and Canada, some of our original markets, the labor rates are high. As we started moving to the Southeast and Southwest, where labor costs are lower, we really had to have a stick-built rack that workers could hand-assemble in the field.
When the transition to trackers happened, we bought the Opal tracker from its Spanish manufacturer. We completely redesigned it. Last year we announced the TDP 1.0 tracker, took it to market and sold 30 or 40 projects. We quickly realized that we wanted to drive down cost. We designed the TDP 2.0 tracker, which we announced at Intersolar North America this year. The reaction has been really positive. The TDP 2.0 has about 25% less cost, so it’s right in there with the current tracker market. One real difference with the new design is we can go to 90 modules per tracker. When you amortize the motor and all the electronics over that larger system, the price point goes down.
JS: Were you surprised to see such a quick transition from fixed to tracked arrays in utility-scale projects?
SD: The price delta used to be huge between the fixed and tracker systems, but it’s very compressed now. Even the installation cost is almost identical. We might get a fixed install for 5 cents per watt and a tracker install for 6 cents per watt. The tracker cost has gone from about 25 or 30 cents per watt to the mid to low teens. The additional energy production washes out that cost.
Am I surprised at some of the places they’re putting trackers? Yes, because the yield with trackers can be anywhere from 10% to 12% more, up to 20% more, depending on where you are in the country. But we’re putting trackers in Montana, Minnesota, definitely Georgia, the Southeast, all over California, and we’re looking at some in Canada. It is spreading. The numbers work, the economics work. Now that trackers have been in the field for 10 years, concerns about O&M are no longer a big deal. There used to be a fear that trackers would be breaking all the time and very expensive to fix, but there’s been enough innovation and new technologies to make O&M less of a sales hurdle.
JS: Solar FlexRack offers a range of turnkey systems and services for its customers. Does this approach eliminate the risks for clients?
SD: The added value we bring is that we have all the services to go along with the tracker. We have geologists on staff, geotech engineers, civil, structural, mechanical and electrical engineers, so we cover all the bases. We have a field services team that manages the installations. There are six people on that team. Three of them are engineers and three are field techs. We have this investment in about 15 people that really helps to make sure the projects get successfully completed.
We’ve actually installed most of the trackers we’ve sold. We’ve done them turnkey, from the geotech work up front, pull tests, design, post installation, tracker installation and module installation. We get a lot of repeat business from these clients because they can adjust their business model: When we get to a certain point, we can hand it to Solar FlexRack and it’ll take over, and we can go do the next project. Our customers become more efficient. The project logistics are tied so much to the mechanical installation. Solar FlexRack’s installation team lead, field services team lead and project management team lead all sit next to each other. It sounds a little corny, but it’s a beautiful setup because they talk to each other every day, and it creates continuity all the way through.
Quality can be a difficult thing to sell—quality in the product, quality in the team, quality in how you deliver the project. I came out of 25 years of managing large software projects in the high-tech industry. In that environment, you learn a lot about how to manage projects. If you manage them correctly, you take a lot of cost out of the system. If they go well, the projected cost is what you end up with. But if you make one mistake in the project, there’s always additional cost, which is really hard to recapture. It’s hard for the EPC to tell a customer, it costs me this much more to do it this way, but we know implicitly that if you design it correctly and look at it correctly, your project cost is much lower. We’ve put a lot of time and effort into that side of the business. And it’s paying off because of repeat business.
Colin Caufield, VP of sales, North America, Soltec, soltec.com
JS: What is Soltec’s company history, including its introduction to the US market?
CC: Soltec launched in 2004. Initially, it was an EPC firm that focused on the European utility-scale solar market. At the time, the market for solar tracking equipment was pretty immature, and we ended up retrofitting a lot of the equipment. This inspired us to design our own product, which started with the dual-axis tracker. As the market evolved—ranging from changes in module pricing to larger market factors—we saw the trend go to a single-axis platform. In 2009, we launched a single-axis tracker that had a different architecture from what we currently sell. It used a central connecting drive, a push-pull style, where you have a lot of rows controlled via one central motor.
That was our product from 2009 to 2011, and we got the inspiration to do what is more analogous to our current architecture from developing a residential product. We made a single-axis tracker product that was for rooftops. From there, we came up with a decentralized architecture. We eventually launched the SF Utility tracker when we teamed up with a big Italian developer and started landing larger projects such as 12 MW and then 80 MW and 160 MW in the Chilean market. These projects helped us further develop our SF Utility tracker, which we’re currently phasing out. However, that product still provides the general form factor of our new tracker, the SF7, which has a few enhancements.
We landed our first large utility-scale project in the US in 2015, a 150 MW system in Minnesota. As that project started to take shape, and the Investment Tax Credit was extended, we saw a lot of regions really come in with more intention. Utilities were seeking out the EPC firms and the developers in the market and having them get an understanding for our product and where it falls within the suite of tracker products that are out there: what gives it value and what gives it advantages, such as our site-fill advantages, our land-adaptation benefits, and being able to utilize really steep slopes or undulating terrain. These advantages highlight why we were a good option and why customers in the international markets have been leaning on us over the years.
JS: What are some of the technical advancements of the SF7 model?
CC: Compared to the SF Utility, the SF7 has a much simpler form factor with the slew drive. We’ve changed the angle at which it connects to the gearbox, and that has allowed us to completely eliminate the gaps and spaces on top of the tracker. Our new tracker has 100% fill. There’s no extra space for dampers or for the motor or an auxiliary module or any of those space inefficiencies. The slew gear has additional enhancements in its performance and torque. In addition to being easier to assemble, it also performs better in high-wind conditions.
We’ve also started producing stamped pieces rather than welded pieces, which has brought down our price per watt. We’re introducing different types of mounting hardware: not just a nut, a bolt and a grounding washer, but rather rivets and also cinch clips, which really cut down on the labor associated with installing modules onto the rack. It helps us standardize all our support structure so that regardless of who the manufacturer is for crystalline panels, we can apply this uniform mounting hardware. Finally, we introduced a dc wire harness that eliminates the need for combiner boxes on the site. Every tracker has its own wire harness that provides overcurrent fusing for three strings. Downstream from that, the cable system has a T connector that allows installers to run strings from one tracker into the torque tube of the following tracker and then into a third and a fourth tracker. This streamlined cabling system really simplifies the installation process. We estimate it saves about 1 cent per watt when looking at the balance of the system cost.
JS: What services is Soltec offering its clients?
CC: We offer layouts for site design. This is an important point to speak to because our tracker is different from some of the others on the market. The design of a layout utilizing another supplier’s products might be different from one using ours. We definitely encourage customers to let us review the site design because we can come up with a lot of efficiencies to either make the site more productive and get more kilowatt-hours out of the plant, or lower some installation cost, such as having fewer linear feet of trenching or less cabling or fewer rows than the customer’s layout shows. We also offer production modeling on the front end. Once projects are starting to take shape, we offer recommendations for foundations based on in-the-field results of geotech analyses. We don’t perform the geotech, but we review it. We recommend designs for conditions per the local codes for wind, snow, seismic and those types of concerns.
We’ve done a lot of our own installations. In other markets, we offer that. In the US, we have done only one project where we performed the mechanical installation of the tracker itself, everything from the pile to the mounting of the modules. We offered that as a way of showing a customer who hadn’t bought from us a proof of labor savings. Soltec can perform that kind of work, which at the very least offers some surety to our customers. Should they need qualified personnel on-site with experience putting our product in the ground, we have those folks on hand whom we can deploy to sites. However, we’re not striving for installations in the US. We don’t want to compete with our EPC customers.
JS: Where do you see the tracker market in a year or two? Are you anticipating any big changes?
CC: I’ve been seeing interest heat up in bifacial modules, and our tracker has some natural advantages when it comes to accommodating that type of module. Because Soltec trackers have a two-up portrait module configuration, the tracker’s torque tube doesn’t shade the bottom half of the bifacial modules. It’s also higher off the ground than some trackers, so it gets more refracted light. We have an installation with bifacial modules, and I’m excited to see this application in action.
Patrick Keelin, director of product management, SunLink, sunlink.com
JS: SunLink is a pioneer in low-slope racking systems for C&I applications, and more recently it introduced both centralized and independent-row array tracking systems. What is the general timeline of SunLink’s product line?
PK: SunLink started over a decade ago with solutions for the commercial rooftop market. We expanded to ground-mount systems and have completed five product design iterations. SunLink’s newest GeoPro system supports both landscape and portrait module installations. The latest iteration of the GeoPro has captured a big chunk of the fixed-tilt market. That heritage of doing five iterations of fixed-tilt systems is really important because it has also informed our tracker design. We acquired the ViaSol tracker about 2.5 years ago and have done a number of projects with it. We also quickly started on development of a new tracker, the TechTrack Distributed. We took the best of what we learned from the fixed-tilt system and what made that system a commercial success, and we applied those lessons to the tracker design.
One of the key items that made the latest iteration of the GeoPro system so successful is that it is highly modular and inventoriable. We use the same set of components and deploy them on many different types of project configurations. This has allowed us to leverage economies of scale. It has simplified our supply chain, reduced our lead time, and ultimately reduced cost and then price for the consumer. It simplified the layout of the projects as well. We applied all of these ideas to the TechTrack Distributed tracker.
A number of innovations within the tracker itself, including pivot design and dynamic stabilization, make it extremely modular. The virtual pivot pulls a lot of torque out of the torque tube. When you combine that with dynamic stabilization, which grounds the torque in multiple places rather than having the torque collect at the slew drive, you can standardize on very few types and thicknesses of torque tubes and posts. The tracker’s bearings, rails and clips are universal—they work for any project.
Mechanically, the TechTrack Distributed has the ability to control the stiffness and damping of the structure in real time, and that’s a true innovation. We’ve introduced a support that we can control according to environmental needs, and that gives us a new dimension to play with when it comes to resisting environmental forces. This has allowed us to reduce the number of posts by 15% and the metal in the torque tube by 20% relative to our TechTrack Centralized model. We’ve been able to standardize a lot of the components and reduce post size. It also provides us an avenue to further cost reductions going forward.
JS: SunLink was early to the game with providing support services such as engineering and geotech. What services does SunLink currently offer its clients?
PK: We offer a very wide range. Geotech testing is one of our most popular services. We offer full turnkey installation of both fixed-tilt systems and trackers for projects under a certain size. Stamped engineering document packages come standard. We have a dedicated project manager. We’ve also introduced an expanded set of services now that we have a more intelligent tracker, which includes data integration support. We have our Vertex data monitoring system, which works with our tracker to give great visibility into how the tracker is performing. The Vertex system is integral to how we deploy and maintain trackers more efficiently.
JS: Are you surprised to see the industry moving so quickly to tracked systems for utility-scale projects?
PK: Not in the US. The generation benefit given the good irradiance is really impressive. The US is especially good for tracking systems and their generation benefit. In a financial model, the increased generation makes a lot more difference than the cost increase, so I don’t think any of us are surprised to see the shift. Where we have been a little bit surprised is the places where people have installed trackers.
Trackers are a great option for many reasons, but we do scratch our heads when customers ask us to quote trackers in Canada and so on, where the irradiance isn’t as good. You don’t get the generation boost that you would in many other parts of the country, and there may be some really high environmental loads, especially snow, that a tracker system simply isn’t as good at dealing with as a fixed-tilt system. SunLink focuses on providing the right solution for the project at hand, and that’s because we offer more than one solution. We can advise the client on what will work better over the long term for a particular site.
JS: What are some of the hurdles or next steps in the development of large-scale array trackers? What pain points is SunLink working on eliminating?
PK: Really using performance data to enhance the system performance over the long term is going to be a big topic of conversation. It goes back to how solar projects are built and financed with the ITC. EPC firms often pick the lowest-priced system. They might hold on to the project for a year and then transfer it to the developer. The developer holds it for 7 years to make sure there’s no recapture remaining on the ITC credit, and then sells it off to an institutional investor. As we go forward and solar matures, we’re going to need a lot more transparency around the performance of those systems. If you capture the performance data—the uptime or some correlation between the environmental events those systems see and the failure rate—then you can start to design more cost-effective systems or systems that can better withstand the rigors of the job in the long term.
JS: What are some important technical considerations when customers are evaluating a tracking system for a specific site?
PK: There are two things. Number one is to match the technology to the job based on the slope or the temperature or the geotechnical characteristics. The decision isn’t just fixed tilt versus tracker. There are a number of different trackers, so site characteristics have an important influence on the equipment selection. It’s not like company X has the best technology; the question is, what is the best technology for this site?
The second important consideration is data integration. Addressing this early in the project development cycle is really beneficial. It’s oftentimes the last thing addressed, but, depending on the architecture that the tracker manufacturer uses, it’s very possible to leverage the intelligence of the tracker system to make a more cost-effective data system. We recently delivered a 60 MW project where the SCADA provider really appreciated that we collected all the information into a single plant controller. Instead of needing to monitor 60 different points, the provider could interface with one device. When working with other tracker manufacturers, it had to interface with 60 or more devices. We always try to provide a simple data interface so the customer has to do a lot less integration work.
JS: You were deeply involved in the development of SunLink’s TechTrack Distributed product. Are trackers an exciting product to be working on?
PK: Oh, yeah. Tracker technology is moving very quickly. A lot of innovation lies ahead. I recently gave a presentation at Intersolar North America where I drew a parallel between where we are with tracking systems and the development history of industrial wind turbines. Wind turbines transitioned from passive to active and fully dynamic systems. It is absolutely amazing how intelligent wind turbines are today. But 20 years ago, the big debate was whether it was worthwhile to adjust the pitch of the blades. That feels a bit like where we are at with tracker systems. The industry is just starting to use intelligent systems to enhance performance, but we have a long way to go. I’m really excited about the future in this space.
Joe Schwartz / SolarPro / Ashland, OR / solarprofessional.com