How we know: Assignment records in the U.S. Patent and Trademark Office's Assignment Center, which we searched directly, plus Nextpower's own press releases and SEC filing. The records show who owns the patents. They don't show a price, and none of the three companies has announced a sale.
ConstructionCase study
Rosendin's solar robot patents went to the company that built it, then to a solar tracker maker
Public patent records show Rosendin signed its robot patents over to ULC Technologies in June 2025. In February 2026, ULC assigned them, plus three related applications, to Nextpower, the company formerly called Nextracker. Nobody has announced a deal.
From the archive. First disclosed in USPTO patent assignment records, January 2026. Where it stands now: Unknown, as of October 2026, no current source found. Why I saved this: The patents moved from Rosendin to ULC Technologies and then to Nextpower, a solar tracker maker, with no announced deal. Sometimes the public paper trail is the only sign of where a technology goes next.
Previously
In February 2025, ENR reported that Rosendin, an electrical contractor that builds utility-scale solar farms, had deployed a three-robot panel-setting system built with ULC Technologies. In May 2025, Rosendin called the system a "working prototype" and was taking purchase offers. Its SVP, David Lincoln, said Rosendin would "either buy them or we will rent them back" if a manufacturer took it on. No price was ever disclosed.
March 2026 — The patents behind Rosendin's solar panel-setting robot now sit with Nextpower, the solar tracker maker formerly called Nextracker, USPTO records show. Here's what changed since Part 2 (May 2025), what it cost, and what went wrong.
Cost and outcome (as of March 2026)
- Cost or sale price: Not disclosed by Rosendin, ULC or Nextpower.
- Step 1: Rosendin assigned patents 11,919,149 and 11,951,617 to ULC Technologies. Signed June 6, 2025; recorded Jan. 6, 2026. (USPTO Assignment Center, reel/frame 73380/0890 and 73380/0514)
- Step 2: ULC assigned both patents and three related applications, five properties in all, to Nextpower LLC of Fremont, Calif. Signed Feb. 19, 2026; recorded Feb. 27, 2026. (USPTO Assignment Center, reel/frame 73920/0272)
- Buyer's stated plans: Nextracker (renamed Nextpower in Nov. 2025) launched an AI and robotics business in July 2025 and lists robotics in its portfolio. (Nextracker, Nextpower)
- Robot status on Rosendin jobs: Unknown.
What the records show
A patent assignment is the paperwork that moves ownership of a patent from one party to another. The USPTO records it but doesn't check the deal behind it.
The first patent, No. 11,919,149, is titled "Autonomous Ground Vehicle for Solar Module Installation." Rosendin filed it in March 2021, and it issued in March 2024. Four inventors are listed, including Lincoln. The second, No. 11,951,617, is "Robotic Arm Cooperating with an Off-Road Capable Base Vehicle."
On June 6, 2025, about a month after the sale window closed, Rosendin signed both patents over to ULC Technologies, the Hauppauge, N.Y., firm that co-developed the robot. The records were filed with the USPTO on Jan. 6, 2026. Separately, ULC engineers assigned their own robot-related inventions to ULC, in records dated from December 2025.
Then, on Feb. 19, 2026, ULC assigned five properties to Nextpower LLC in Fremont, Calif., the record shows: the two Rosendin patents and three related applications. One is application 18/584,950, a continuation of the robotic-arm patent's application, per Google Patents; it was still pending at the time of the transfer. Another is titled "Automated Solar Robot System and Method." The assignment was recorded Feb. 27.
Who Nextpower is
Nextpower is the new name of Nextracker, which makes solar trackers, the motorized racks that tilt panels to follow the sun. The rename took effect Nov. 12, 2025, and the company said its portfolio now spans trackers, electrical systems, software and robotics.
In July 2025, Nextracker launched an AI and robotics business. It named its first chief AI and robotics officer, Francesco Borrelli, and said it had spent more than $40 million over four quarters on three AI and robotics acquisitions: OnSight Technology for robot inspection, Amir Robotics for panel cleaning, and SenseHawk IP for drone site mapping. None of those set panels. The Rosendin and ULC patents do.
What's changed
In May 2025, the robot was for sale and the buyer was open. Ten months later, the patents sit with a tracker maker, the company whose racks the robot sets panels onto.
There's still no public deal. We found no announcement from Rosendin, ULC or Nextpower. The USPTO record doesn't say whether ULC sold the patents, licensed them back, or folded them into a bigger transaction. It doesn't say whether Rosendin still runs the robots or will rent them, as Lincoln described.
Why it matters
If Nextpower turns this into a product, a robot designed by a contractor could reach other contractors through the supplier that already ships them the racks. That's the path Rosendin wanted: buy or rent, not build.
What went wrong
- No one has said what happened. The ownership change is public only through patent records. No price, no terms, no product plan.
- Rosendin's robots are out of sight. We have no public report of the robots on a Rosendin job since May 2025.
- An old lien is on the record. The records for both patents also show a security interest, a lender's claim, granted by Rosendin and an affiliate, Modular Power Solutions, to BMO Harris Bank as agent, effective April 28, 2021, and recorded on Feb. 11, 2022 (reel/frame 58986/0868), per Google Patents and the USPTO assignment record. We couldn't tell from the record whether it has been released.
- Still no cost per panel. Three steps in, the basic operator question is unanswered.
Our follow-up question for Nextpower
Will Nextpower build and sell or rent a panel-setting robot based on the Rosendin and ULC patents, and when could a contractor get one?
Since publication
- Added March 2026: Application 18/584,950 was granted on March 10, 2026, as patent No. 12,569,987, with Nextpower LLC listed as assignee. (Google Patents)
Sources
- USPTO Assignment Center, patent 11,919,149: reel/frame 55648/0948 (inventors to Rosendin), 58986/0868 (security interest), 73380/0890 (Rosendin to ULC) and 73920/0272 (ULC to Nextpower). Look up by reel/frame at assignmentcenter.uspto.gov
- USPTO Assignment Center, patent 11,951,617: reel/frame 55648/0808 (inventors to Rosendin), 73380/0514 (Rosendin to ULC); ULC to Nextpower, reel/frame 73920/0272 (five properties). Look up by reel/frame at assignmentcenter.uspto.gov
- Nextracker, “Nextracker Launches New AI and Robotics Business with Technology Acquisitions and New Executive Appointment,” July 29, 2025. businesswire.com
- Nextpower, “Nextracker Rebrands as Nextpower…,” Nov. 12, 2025. investors.nextpower.com
- Nextpower Inc., Form 8-K (name change), Nov. 12, 2025. sec.gov
- Art Aiello, “Autonomous robot aims to ease heavy lifting at solar farms,” *Power Progress*, May 10, 2025. powerprogress.com
- Google Patents, US 12,569,987 B2 (application 18/584,950), legal events and parent application. patents.google.com
- Earlier in this series: Parts 1–2. /case/rosendin-solar-robot-deployed, /case/rosendin-solar-robot-for-sale
© 2026 Real World Wire. Written October 25, 2026.