US turns former nuclear plant into low-energy polysilicon facility
A US nuclear power plant site is set for a new chapter as a hub for advanced manufacturing.
A real estate investment group plans to redevelop about 140 acres at the former Phipps Bend Nuclear Plant in Hawkins County to host a 16,000 MT polysilicon plant anchored by Highland Materials, a new polysilicon manufacturer.
The property already features a Phipps Bend Nuclear Plant (TVA)-owned regional transmission interconnect and a 1-MW solar project completed in 2017.
According to the company, its energy-efficient process uses significantly less power and space than conventional silicon manufacturing methods, requiring only 20–40 kWh to produce one kilogram of silicon.
Highland energy hub
Pivotal Manufacturing has taken over 140 acres in Hawkins County, Tennessee, where the ill-fated Phipps Bend Nuclear Plant was abandoned decades ago after reaching just 40 percent completion and accumulating more than $2.6 billion in debt.
According to PV Magazine, the company has secured a long-term ground lease with Highland Materials, which will anchor the site with a new advanced manufacturing facility for solar-grade polysilicon, alongside a campus of other energy-related projects.
According to the US Department of Energy, Highland’s plant will produce 16,000 metric tons of polysilicon annually at “less than standard cost.” Within four years, capacity is projected to reach 20,000 metric tons annually—enough to supply the equivalent of 11 gigawatts of solar cells. Last year, the company was allocated $255.6 million in Qualifying Advanced Energy Project Credits (48C) from the Inflation Reduction Act.
The transformation is made possible in part by infrastructure inherited from the abandoned nuclear project, including a high-voltage regional transmission interconnect, flexible zoning, and a permitting environment tailored for large-scale industrial development, reports PV Magazine.
Partnering with Pivotal Manufacturing Partners is critical to moving the Highland polysilicon manufacturing facility forward at Phipps Bend. We are excited about the market opportunity, the job creation, the capital investment, and the continued community and state-level support this project enjoys,” said Richard Rast, CEO of Highland Materials, as reported by Solar Power World.
Energy-efficient silicon
Highland Materials plans to introduce a next-generation, energy-efficient production process at its new Tennessee facility, using a scaled-up aluminum–silicon alloy smelting system.
This method combines impure raw silicon with pure aluminum, lowering the melting temperature compared to conventional polysilicon production. This innovation reduces energy use to just 20–40 kWh per kilogram—well below industry norms—while maintaining ultra-high product quality and significantly reducing the plant’s environmental footprint, reports Construction Review Online (CRO).
Polysilicon, or polycrystalline silicon, is an ultra-pure silicon that forms the base of over 90 percent of the world’s solar panels. Production starts with quartz, which is refined into metallurgical-grade silicon, then purified—often via the Siemens process—by converting it to trichlorosilane gas, distilling out impurities, and depositing pure silicon onto heated rods. The resulting rods, exceeding 99.9 percent purity, are broken into chunks, melted, cast into ingots, and sliced into wafers for high-efficiency photovoltaic cells.
According to CRO, polysilicon production is energy-intensive and currently dominated by China, making it strategically important for US energy independence. Highland’s Tennessee facility will help reduce import reliance, secure domestic supply chains, and support US solar projects. Upcoming manufacturing plants, such as a planned US$200 million solar panel factory in Ohio, stand to benefit directly from this domestic source.