Article by – Solar Builder
Terrasmart unveiled its new hail stow feature for both of its 1P and 2P trackers last year. The following is a conversation with John Goetz, Senior Product Manager – Ground Mount, Terrasmart, to learn more about modern stow strategies. Read the full interview here.
Q. The solar industry is facing more frequent and damaging extreme weather events, including hail. Can you help us understand the impact hail has on plants in the US?
Goetz: We all know that hail storms pose a significant threat to solar power plants in the U.S., and incidents are becoming more frequent and destructive. In 2022, hail-related losses in Texas alone surpassed $300 million, highlighting the vulnerability of solar infrastructure to extreme weather. Over the last five years, hail has accounted for 50% of all insured project losses in the solar industry, despite representing only 2% of total claims by number. This disproportionate impact underscores the severity of hail damage. This March we also saw a 350-MW project devastated by a hailstorm, also in the Lone Star State, destroying thousands of solar panels. As the solar industry continues to grow, we are all working to prioritize risk management strategies to mitigate hail damage and ensure long-term viability.
Drainage, snow, and aesthetics
Snow load is also a consideration in designing the slope and directions of sections of the array. “We can basically funnel everything [rain and snow] toward the middle. We can do alternating slopes on those inverted areas, so we can have one side sloped seven degrees while the other side slopes one degree,” Fey says, noting Terrasmart engineers have designed for slopes as steep as 10 and 15 degrees. “Whatever you’re looking for in a type of configuration, we can make happen.”
Beyond slope control, adding gutters will capture and direct water flow from the canopy. “Typically, on these structures, we’ll install a gutter system to help collect any type of snow or ice that may fall, preventing it from falling down into the parking lot,” Fey notes.
“With all of our canopies, we offer the options for gutters and downspout systems. When we’re collecting the water, we can mitigate the impact, drain it into an underground retention system, or drain it out to the parking lot, or even out to a berm behind it.”
Aesthetics, finally, can also be enhanced on a canopy array. “We can trim out the purlins. We can do them in colors. It’s a more sophisticated aesthetic feel that gives you more of a finished edge around the whole canopy structure,” says Fey.
Q2. Can you start with an overview of Terrasmart’s new hail stow functionality and related benefits?
Goetz: At Terrasmart we offer both fixed tilt and tracker systems, but when it comes to hail, trackers are specifically designed to reduce damage by detecting severe storms and repositioning themselves to minimize impact, offering a clear advantage over fixed-tilt systems.
First we start with PeakYield™. This intelligent tracker software boosts energy yield while also protecting assets during bad weather such as hail. It adjusts each tracker row to reduce shading, so the panels always get the best exposure and maximize production. Our system includes a weather station, a network controller, and a row box for each tracker row, all working together to provide real-time data on site performance. It’s all about maximizing efficiency and value for our projects.
PeakYield is designed to minimize weather risks. When hail conditions reach certain thresholds, the system automatically commands the site to stow, which helps prevent damage. Plus, we use an advanced weather API that predicts incoming bad weather, so the system can stow the panels ahead of time.
Our Hail Stow feature is available for both our TerraTrak 2P and 1P trackers, and we mainly recommend it for trackers in areas where hail is a significant concern.
What’s really important is that it operates automatically. This means you don’t have to manually intervene when hail is detected—this is crucial because we’ve seen some sites suffer serious damage from hail simply because the system wasn’t activated in time.
Another key point is that our wind and hail stow strategies are aligned. When our weather stations detect hail or severe thunderstorms in real time, they automatically adjust the trackers to a high-tilt position, away from the wind direction. Specifically, for the TerraTrak 1P, the system will stow at +/- 50 degrees, and for the TerraTrak 2P, it will stow at +/- 60 degrees. This feature is particularly useful if your trackers are set to wind stow at a high-tilt angle.
Next questions:
- Which guiding parameters did the team prioritize for the hail stow technology?
- What do Terrasmart customers value most about your tracker portfolio and this new hail stow technology?
- What is Terrasmart’s approach to mitigating risks from hail and how does this differ from other tracker manufacturers?
- Beyond using a tracker with hail stowing capabilities, what else can you do to further reduce the risk of hail damage?
