Castillo Engineering Launches Venture for Solar Letters, PE Stamps


Castillo Engineering has launched, an offering that fully automates structural letters, professional engineer (PE) stamps, and post-installation letters for residential solar installation companies in all 50 U.S. states, as well as for overseas design firms.

The company’s advanced automation enables a 99% accuracy rate, Castillo Engineering says. Backed by over 25 years of structural design and engineering experience in residential solar, Solar Letters will also be incorporating artificial intelligence to further reduce the time and costs associated with solar letters and PE stamps. Solar Letters’ experience, combined with its advanced technology, has enabled it the capacity to generate over 100,000 solar letters per month, allowing residential solar installers to complete more projects in less time.

“The Solar Letters platform is a game-changer for LGCY,” says Ben Ogden, manager, design and engineering, for LGCY Power. “It has simplified the structural and electrical engineering process and increased our turn times on stamped projects.”

There are currently many costly inefficiencies within the solar letter and PE stamp process in the residential solar industry, with most firms still performing calculations manually or using Word or Excel documents. All of these methods have been tested and proven to be highly error-prone, particularly with non-degreed engineers manually completing many letters per day. As a result of investing in advanced automation and its database of over 40,000 authorities having jurisdiction, and associated codes that have been continuously updated since 1998, Solar Letters has been able to guarantee its 99% AHJ approval rate.

“We are very excited to launch in response to the high demand for residential solar letters and PE stamps we are seeing globally,” says Christopher Castillo, CEO of Solar Letters. “We look forward to providing the same elite customer service experience for clients as we do through Castillo Engineering. Helping solar installers drastically cut soft costs and mitigate project risks are necessary to ultimately enable solar energy to proliferate across the globe.”

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