Oracle’s Wisconsin Data Center Has a Power Problem

On September 30, 2026, infrastructure data firm Aterio published an analysis of Project Lighthouse. That's the 1.3 GW data center campus Vantage Data Centers is building for Oracle in Port Washington, Wisconsin.

Aterio sees a material risk that the site misses Oracle's delivery guidance for the second half of 2027. By their read, meaningful load is unlikely to arrive before the middle of 2028.

Vantage has said they expect full campus buildout by 2028.

Construction doesn't appear to be the limiting factor. Permits are in hand, and crews have worked continuously since December 2025.

Satellite imagery shows 2 of the 4 halls already enclosed, so the buildings are doing their part.

The real constraint is power. The campus can't operate until American Transmission Company (ATC) builds a new high voltage interconnection. That work can't begin without approval from the Public Service Commission of Wisconsin (PSC).

ATC's first application spent 10 months under review. In August 2026, the PSC revoked its completeness finding and closed the case, citing hundreds of changes to the project's scope made after filing.

The Commission was clear that it wasn't ruling on the merits. ATC refiled in September 2026, which reset the statutory clock under a new docket.

"Construction at Port Washington is progressing steadily, but power delivery depends on a regulatory process that has restarted," said Javier Reyes, Head of Data Center Research at Aterio. "Based on the public record, we see a meaningful risk that load arrives later than Oracle's current guidance."

Aterio modeled three timelines, each based on when the PSC issues its written order. The fastest legal path puts partial power around October 2027 and the full 1.3 GW around August 2028. Aterio calls that unlikely, since no comparable Wisconsin case has moved that fast.

In their base case, the PSC decides within 180 days. Partial power would arrive around December 2027 and full capacity around October 2028, with customer load ramping mainly from the first quarter of 2028.

A full 360 day review pushes partial power to around June 2028 and full capacity to around April 2029. That scenario carries weight, since the PSC used its extension in every comparable large transmission case Aterio reviewed.

These dates are Aterio estimates drawn from regulatory filings, state law and past PSC cases. They are not commitments from ATC, the PSC, Vantage or Oracle.

The next milestone is the PSC's completeness decision, expected around October 19, 2026. ATC is also expected to file with grid operator MISO around then on a device to stabilize voltage near the campus substation.

Construction isn't the bottleneck here, and that creates its own exposure. Finished buildings waiting on power tend to rack up extended general conditions, remobilization costs and warranty questions. Subs on electrical and mechanical scope should check now how their contracts treat a building that's complete but not energized.

The October 19 ruling is a procedural step, not the green light, since ATC can't build until the PSC issues a written order. Aterio's base case assumes a 180 day decision. Still, the PSC used its extension in every comparable case Aterio reviewed, so transmission bidders should leave room for the longer review.

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