Product and industry continually advance through phases of innovation brought on by a desire for ease of use, either to address challenges within a market or to improve cost and accessibility. Solar trackers have been around for years; however, recent, groundbreaking innovations show that the market is more vibrant than ever.
Similar to solar modules, early stages of tracker development required progress beyond the hobby garage. Industrialization was inevitable to reduce costs, increase quality, and support large-scale installations.
Single-axis solar tracker technology initiated from the fixed tilt market as a desire to optimize output. The logic – a solar track that tilts on a horizontal axis structure would offer greater solar energy generation than a fixed tilt could deliver.
As simple as that seems, trackers are much more complicated from a structural perspective, and require an entirely new aspect of control system development. As moving systems, trackers need to be designed for a wider range of loading conditions than conventional structures. At the same time, there is an opportunity to respond dynamically to weather conditions to minimize loading on the structure.
As tracker demand increased, companies rushed to enter the market before fully understanding the additional complexity of tracker systems. This early entry industry gateway gave way to companies retreating from the industry all too quickly.
Several fixed tilt structure companies designed and deployed trackers with mixed results. International tracker companies attempted to enter the US market, only to realize the barriers to entry and significant ongoing support costs (engineering, construction, services) were challenging further attributing to the contraction of the solar tracker market.
Rising to the challenge
Once solar tracking was established as a baseline technology, increased demands and the challenge to innovate grew incessantly. Project sites became more difficult, the size/magnitude project scope increased, and the requirements of the market rose substantially, as trackers now competed on the same industrial level as established products entering 30-40-year lifespans.
New solutions often come with some pushback, and the initial reluctance companies had toward solar trackers were cost, risk and reliability. Concerns that innovation and technology has since resolved, because many of today’s trackers are cost efficient, lower risk and extremely durable.
While there have been advancements in the market since first arriving on the scene, the functionality of single axis trackers remains the same: North-South rows that rotate East to West following the sun. What has evolved is the underlying architecture below the modules. As the industry has learned from wind tunnel testing and field failures, a wide variety of strategies have been developed to most efficiently distribute forces and reduce the risk of failure. These variations are visible above the modules only as varying row lengths and 1-up vs 2-up configurations.
A bright spot in the solar tracking market
Valmont Utility’s acquisition of Convert in 2018 was a step toward innovation within the solar tracking industry. Their long-trusted history of metal fabrication, galvanization, coatings and corrosion protection allows for improved design, cost containment, supply chain, support and reliability in North America, and across the globe. Valmont’s ability to lend their experience with transmission towers, distribution pole manufacturing and substation design and engineering will improve overall performance and reliability of the TRJ Solar Tracker for years to come.
Valmont Utility’s Convert TRJ single-axis tracker uses innovation and technology to address the continued and ever-changing needs of the market. For instance, self-powered, battery-based systems use batteries that need to be replaced every seven to ten years, racking up additional O&M costs. The TRJ employs a groundbreaking, string-powered controller using existing DC wiring that eliminates the need for batteries entirely. It also automatically receives battery-free backup power from the grid. This not only lowers overall system costs it makes the machine that much more reliable.
The Convert TRJ tracker has the ability to address difficult terrain with smarter and simpler construction and installation, and the capability to use less energy. One of the greatest cost factors for trackers are typically found in grading, excavation, and foundations. However, the TRJ system decreases risk and costs with reduced grading and higher field tolerance for foundations with the use of single-string row lengths.
This innovation provides a more rigid and sturdy design and lessens dependency on dampers. It also allows for snaking over grade changes as well as for fitting more solar between site obstructions. The ease of installation on topographically challenged terrain allows for more modules on landscapes once thought of as too prohibited or requiring too much civil planning and land development.
If one thing’s for sure, solar trackers will continue to advance. Controller architecture and software engineering will constantly adapt to meet the demands of the changing landscape and focus on optimizations. Trackers will look to optimize the capture of energy with newer technology like Bifacial Solar Modules, which allow for increased production by taking advantage of the light reflecting off the ground and its surroundings.
The future is bright for innovation in the tracker space. Over the next several years advancements in AI, integration with string inverters (i.e., the ability to optimize each string for maximum power production) and ability to better manage various environmental conditions will continue to drive new solar tracker technology.
Valmont Utility’s Convert TRJ single-axis tracker will begin to expand on a string by string basis, allowing for maximum output with less equipment. Technology within solar trackers hasn’t stalled, if anything, it’s now more refined and optimized for energy output and total project success.
Written by Lauren Ahsler, Valmont Utility Senior Manager of Structural Engineering, Solar