Old Oscar Mayer factory to become Wisconsin fusion research hub

The former Oscar Mayer plant on Madison’s northeast side is being remade into a fusion research and manufacturing center as Realta Fusion moves into 2099 Roth St. The startup calls the project “The Realta Forge,” a purpose-built headquarters and facility that would convert more than 200,000 square feet into offices, research space and manufacturing space.

Realta Fusion was spun out of a plasma physics experiment at the University of Wisconsin-Madison in 2022 and had been operating on Madison’s west side before choosing the former hot dog factory site. The company has said the move will support the next phase of scaling up its fusion machines, including a prototype device, and that it aims to build a commercially viable fusion device prototype by 2028.

Public money is central to the deal. Wisconsin has committed up to $55 million in support, and the Madison City Council approved a $2.8 million Jobs TIF loan to help Realta move into the vacant property. Supporters have said the redevelopment could bring new life to a long-vacant industrial site and help create and retain family-supporting jobs in the city.

The project is also being built on a growing private-finance base. Realta has raised more than $45 million in venture capital and recently added $9.5 million in debt financing from Silicon Valley Bank to support growth. That mix of public incentives, venture capital and bank debt shows how fusion companies are increasingly leaning on industrial sites, local subsidies and manufacturing space rather than pure laboratory campuses.

For Wisconsin, the former Oscar Mayer plant has become a test case for a bigger economic strategy. State lawmakers, business groups and fusion advocates have been trying to position the state as a national center for fusion energy research and manufacturing, and the Realta project puts that goal inside a building with a very different industrial past.