Silfab Solar halts operations at South Carolina plant after chemical spills

Image: Silfab Solar

Silfab Solar has paused operations at its solar module manufacturing facility in Fort Mill, South Carolina, following two chemical spill incidents that prompted a stop-work order from state regulators.

The South Carolina Department of Environmental Services (SCDEP) issued the order earlier this week after separate spills occurred at the company’s manufacturing plant in Fort Mill, located in York County.

The incidents reportedly involved around 300 gallons of potassium hydroxide and an unspecified quantity of hydrofluoric acid, both of which are commonly used in the production of solar cells—particularly during the wafer texturing process.

According to local media reports, authorities said the spills do not pose an immediate threat to public safety. However, a nearby primary school was temporarily closed as a precaution.

The potassium hydroxide spill earlier in the week reportedly leaked into and around the facility’s on-site retention pool. A separate hydrofluoric acid spill that occurred the following day was successfully contained before spreading beyond the immediate area.

Silfab is not expected to resume manufacturing operations immediately. The shutdown follows pressure from Michael Johnson, who wrote to the SCDEP urging the agency to suspend operations at the plant until a full state investigation is completed.

In a joint statement with David Martin, Johnson said regulators had agreed to take legal action if operations resume prematurely.

“At our urging, the Department of Environmental Services has agreed that if Silfab resumes operations of any kind, DES will take immediate legal action and file a lawsuit seeking a restraining order to stop any work from occurring on site,” the statement read.

Company representatives have addressed the situation publicly, with Silfab’s director of operations, Greg Basden, speaking to local media about the incidents.

The Fort Mill facility is part of Silfab’s broader effort to expand its U.S. manufacturing footprint. The company has been upgrading the site to produce solar cells as well as modules, positioning itself among a relatively small group of U.S.-based manufacturers pursuing domestic solar cell production.

Silfab has secured private investment and federal tax credit support to fund the expansion.

However, the project has faced local opposition since its early stages, largely due to concerns about the plant’s proximity to a nearby school and potential environmental and safety risks for students and local residents.

These concerns previously delayed the start of operations at the facility, which had originally been scheduled to begin production in late 2024.