The solar industry is ironic: just when we ran out of flat land, solar trackers became the preferred method of installing solar projects on the ground. Slopes, undulating terrain and rocky landscapes are the norm today. These conditions present engineering and cost challenges for any ground installation project, especially for trackers.

OMCO Solar’s ​​technical director Matt Kesler said: “Just a few years ago, the answer was'move soil', because the leveling of the site made tracker installation easier. But for some reasons, this The situation has changed. As the number has increased, the cost of solar modules, trackers, and everything else has fallen, which usually makes the cost of grading the site no longer acceptable. In addition, RFP began to exclude them because of more Good land management is a greater priority for utilities and municipalities.

"Customers say site selection becomes more challenging. Some people try to reduce the score or not to score at all. By simplifying stormwater management and bringing ecosystem benefits to the project site, this makes permitting easier," Sunfolding Vice President of Business Development Ryan Kelly said.

We discussed with three solar tracker manufacturers how they can overcome the challenge of irregular venues while addressing other emerging obstacles, such as large-size modules and steel prices.

The question is not true, "Can we install solar trackers on that site?" The question is how expensive or complicated you want the solution to be.

Grading uneven and undulating sites is a considerable expense, especially in the northeast where labor costs are high. To avoid these, the tracker improves its fluctuation tolerance by mixing stack heights, usually adding steel and increasing structural forces and/or using shorter rows.

Benjamin Kahane, director of performance engineering at FTC Solar, said: "For projects on wave terrain, we have increased the fluctuation tolerance to increase the allowable pile height, up to 3 feet or so." "You can make the tracker side 10 higher. Feet, and 7 feet higher on the other side."

Other random costs to consider when mixing different pile heights: A higher undulation tolerance may mean more ladder work and more engineering time for the installer. Part of the cost saved by avoiding site grading may be lost due to the increase in steel prices, but Kahane said that “in terms of grading cost savings, this is more than it has paid for itself.”

If the customer wants to obtain additional particle size, these steel costs can be further reduced. Kahane showed me the complex website they designed for a client this year, which had a dozen different color-coded sections and indicated different maximum/minimum heights and embedding depths.

"This requires a lot of due diligence, but the customized embedding depth will save them steel costs," he said. "We can say just embed them all to 10.5 feet, because this is the most needed depth, but the customer is looking for additional cost savings, so we have become more complicated."

Design adjustments don't stop there. As tracker manufacturers customize the design layout for each site, they also integrated design adjustments to accommodate large format modules. FTC's Voyager Plus is an example: the motor is larger, the torque tube is stronger, the guide rail is longer and thicker, and the number of dampers is increased.

But this cost equation is a moving target. Since we chatted with Kahane, steel prices have risen more, and supply chain issues have become worse, not better, in general.

"Of course, the cost of steel is worrying," said Eric Goodwin, director of business development at OMCO Solar. "At this time last year, the cost of five MW tracker projects was 17 cents, and now their prices are between 31 and 33 cents."

The core of OMCO is a steel company, so it does have an advantage in this regard. "We have been able to price our steel products 18%-20% lower than our competitors, and pass these savings on to our partners and ultimately to the end customer," Goodwin pointed out. "We are very transparent to our customers-showing them the steel index so we can show them why this is happening. We are also more strategic in terms of profit margins, so we can provide our customers with the absolute best price ."

Purchasing steel domestically rather than overseas also helps avoid problems related to shipping delays and freight costs. This may be the difference between a lead time of 6 to 8 weeks and a lead time of 20 to 24 weeks. "Our domestic manufacturing capabilities mean that we can turn things around in a few weeks-sometimes even days-and we have more opportunities for fine-tuning," Kessler said. "We have internal structural engineering, so we can change the length and cross-sectional dimensions of each solar structure we make."

OMCO Origin Factory-Direct Tracker is provided in two ways: 1) Optimized single-portrait design of single-sided modules, for example, including First Solar 6 series thin film modules. 2) Two-in-one landscape tracker for double-sided modules. Since column height and driving accuracy are so important, the tracker system still needs a little leeway and adjustability. For example, OMCO Solar's bearings allow height adjustment to compensate for defective column heights.

"We usually recommend long trackers-we can provide trackers with up to 120 modules-because this reduces tracker costs, installation costs, and O&M costs-reducing motors and controllers per megawatt," Kay Sler said.

So far, OMCO's focus has been on the DG market of 10 MW and below, but Goodwin said that they will carefully study the utility-scale market and "plan to start the project in the middle of 2022."

Utility-scale sites increase the risk. According to a report from the US Energy Information Administration in February 2020, the estimated cost of civil and structural engineering for a 150 MW solar project is 5.3 cents per watt. The estimated indirect cost including cranes and scaffolding is 1.4 cents per watt. These projects, excluding construction labor and post-materials, contributed $10 million to the total cost of the project. Costs may vary greatly depending on site conditions.

The Sunfolding team pointed out that there is a trade-off between the extra cost of a shorter tracker row and the extra cost from cut-and-fill excavation and variable-length struts. These shorter lines do increase hardware costs because the electromechanical equipment is not optimally utilized.

"By eliminating motors, short tracker spans (as small as or below the size of a single string) can be adapted to the terrain with minimal interference. Bart Oegema, director of product management at Sunfolding, points out that there are no additional unexpected costs for earthwork, nor' Part of the line' extra cost. This blog post delves into the topic.

The short-span motorless tracker adapts to the terrain, allowing the array design to adapt to the characteristics of your site, from hills to swamps, or the right of way for endangered species. Tracker rows are no longer partial, they are just modular, site-specific spans.

The high-efficiency system design can adapt to the undulating terrain, the column can maintain the middle slope of the slope and the minimum embedding requirement, without digging and filling. In this way, solar trackers without motors can be deployed on undulating terrain without causing extensive damage to site features or creatures.

Sunfolding's T29 can actually follow the land, and can be deployed on sloping terrain, the unit cost is the same as the tracking system on flat ground. Folding requires an average of 10 cubic yards of earthwork per acre (other trackers may require an average of 230 cubic yards of earthwork per acre on undulating terrain). The shorter tracker row allows Sunfolding to use a single column length and avoid the cost of heavy machinery and rigging, as well as the additional labor and material costs required to drive extra long columns.

"Trackers need to adapt to the scene, not the other way around," OMCO's Kessler said of today's expectations. "Tracker vendors need to look at each site, decide if they can support it without scoring it, and advise customers accordingly and honestly. Then support them by helping customers fulfill their promises."

There are plenty of video interviews and other content on our YouTube page. Recently we launched Power Forward! — Cooperate with BayWare to discuss higher-level industry topics and best practices/trends for operating solar business today. Our longer-running side project is The Pitch-in this project, we have awkward discussions with solar manufacturers and suppliers about their new technologies and ideas so you don't have to. We discussed everything from residential trackless deck connections and home solar financing to large-scale energy storage value stacking and utility-driven new home solar storage microgrids. We also posted our annual project announcement there! Interviews with this year’s winners will begin in the week of November 8. Go there and subscribe today to learn about all this extra content.

There are plenty of video interviews and other content on our YouTube page. Recently we launched Power Forward! - Cooperate with BayWare to discuss higher-level industry topics and best practices/trends for operating solar business today. Our longer-running side project is The Pitch-we have awkward discussions with solar manufacturers and suppliers about their new technologies and ideas so you don't have to. We discussed everything from residential trackless deck connections and home solar financing to large-scale energy storage value stacking and utility-driven new home solar storage microgrids. We also posted our annual project announcement there! Interviews with this year’s winners will begin in the week of November 8. Go there and subscribe today to learn about all this extra content.

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