The movement of panels that have been stuck at the border or awaiting shipment from overseas should alleviate some gridlock in U.S. solar project development from implementation of the Uyghur Forced Labor Protection Act, which went into effect in June of last year.

"There's clearer guidance out, and we're seeing more shipments coming through," John Podesta, a senior adviser to President Joe Biden on clean energy matters, told reporters on the sidelines of the CERAWeek energy conference in Houston.

Major Chinese manufacturers echoed Podesta's statement.

Trina Solar Co Ltd, a major Chinese solar manufacturer, told Reuters that more than 900 megawatts of solar panels has cleared U.S. customs in the last four months, with less than 1% of those products being detained for examination.

"Trina's data systems and supply chain management allow us to provide detailed traceability documentation, upon request by the US Customs," a Trina U.S. spokesperson, Melissa Cavanagh, said in an email. "This has significantly reduced delays at the ports."

Trina rival Jinko Solar Holding Co Ltd has also had shipments released from detention, a source close to the company said.

(Reporting by Richard Valdmanis in Houston; Editing by Chris Reese and David Gregorio)