Oracle's Project Lighthouse: Power Delays Put 2027 Target at Risk

Filings reviewed through 24 September 2026.

Project Lighthouse is a four-building data centre campus that Vantage is developing in Port Washington, Wisconsin, with Oracle as the tenant. It cannot operate until a new high-voltage transmission project is built. American Transmission Company (ATC) first asked the Public Service Commission of Wisconsin (PSC) to approve that project in September 2025. In August 2026, after ten months of review, the PSC withdrew its finding that the application was complete and closed the case. ATC refiled in September, restarting the statutory clock under a new docket. Oracle is still guiding to customer delivery in the second half of 2027.

This report looks at two questions: when can Lighthouse realistically draw power, and is the stated 2027 start still realistic? Aterio’s conclusion is that there is a real risk of delay. The regulatory record points to the potential for dates later than company guidance, and Oracle’s stretched finances, together with its force majeure notice on Project Jupiter in New Mexico this week, raise the potential for slippage on its largest campuses.

Executive assesment

The campus build itself is not the constraint on Lighthouse. The permits are in hand and work has run without a break since December 2025. Two of the four buildings are enclosed, and the other two are in structural work. The problem is power. The campus cannot run until ATC connects it to the grid, and ATC cannot start building until the PSC approves its application. As a result, the pace of construction says little about when the campus will run, or at what scale. Finished buildings that cannot draw power would be the outcome of a delay.

Company guidance does not resolve the question either. Oracle expects customer delivery in the second half (H2) of 2027. Vantage expects full campus buildout by 2028. These are different milestones, and neither specifies how much power will be available, or when. That gap matters more after this week, given recent concerns surrounding Oracle’s sister campus, Project Jupiter.

ATC will deliver power in two stages. Partial power will arrive about seven months after construction of the transmission project starts, and the full 1.3 GW will arrive after about 17 months. Our base case assumes the PSC decides within its standard 180 day decision period. Under Wisconsin law, the PSC has 180 days to rule once it accepts an application as complete, and may extend that once by up to another 180 days. That gives partial power around December 2027 and the full 1.3 GW around October 2028. December 2027 is just inside Oracle’s H2 2027 window, but each building then has to be tested and commissioned. We therefore expect the campus’s load to ramp up mainly from the first quarter of 2028.

The main risk is a longer review. The PSC extended its review in every comparable case we reviewed. If it does so here, each date moves back by about six months, to around June 2028 for partial power and April 2029 for the full 1.3 GW. Taken together, including in the context of Oracle’s wider buildout, Aterio notes a material risk that Project Lighthouse misses Oracle’s H2 2027 guidance and that meaningful load does not arrive until mid-2028 or later.

Where things stand

Construction of the data center buildings themselves has all the approvals it requires. The city approved the project in August 2025. In December 2025 the Wisconsin Department of Natural Resources (DNR) granted wetland exemptions and stormwater coverage, and issued its environmental determination. The backup generator air permits followed in June 2026. A lawsuit over the city’s tax increment financing was dismissed in September 2026. A Sierra Club challenge to the generator air permits is still pending, but it has not produced a ruling or an order to stop work. We do not expect this challenge to succeed and do not expect it to delay the project beyond the more pertinent transmission line constraints.

The campus’s capacity is quoted in different ways. Vantage quotes 902 MW of critical IT load, which is the power that reaches the computing equipment. The modeled IT load, based on the campus’s electrical plans, sits at ~1.1 GW. This includes the data modules and networking racks. Utility records quote 1.3 GW of total electrical demand, which counts cooling and anything else the site draws.

Why the first application was withdrawn

The PSC did not reject the project. Its final order of 10 September 2026 says the decision “is not a determination on the merits”, and it invited ATC to refile.

The problem was that the application kept changing after the PSC found it complete on 15 December 2025. ATC went on to file or refile 564 more application documents. Its supplemental testimony in June and July 2026 added route changes, new temporary bypass lines, a revised uprate scope and new cost estimates.

On 1 July an administrative law judge ordered ATC to list every change and the reason for it, and on 15 July found that it had not. The Commission decided it could no longer be sure what project it was being asked to approve. The late additions would also need a further environmental review that the legal deadline left no time for, so the project risked being approved by default. The PSC therefore revoked its completeness finding on 6 August and closed the case on 10 September, saying any new application must “clearly explain the Project”.

After more than a year, the process is back where it began. This is the single largest source of delay risk: ten months of review produced no decision and the process has to be re-run from the beginning. It is expected that the revised application will achieve completeness, but not guaranteed. PSC staff asked 483 questions over 16 rounds during the first review, and ATC says the new application addresses the feedback from that case. Every comparable case reviewed for this report, including the original filing, was found incomplete at least once before being accepted.

How the timeline works

The approval clock

Three provisions of Wisconsin law (Wis. Stat. § 196.491(3)) set the pace for regulatory approval and, thus, construction.

1. Six months’ notice: ATC must file its application at least six months before it starts construction. The PSC recorded the new application as received on 18 September 2026, so construction cannot start before about 18 March 2027.
2. 30 days to check completeness: The PSC has 30 days to decide whether the application is complete, which runs to about 19 October 2026. If it does not act within that period, the application is deemed complete by law. If it finds the application incomplete, ATC has to refile and the 30 days start again. That happened to the first application, which was found incomplete in October 2025 and refiled in November.
3. 180 days to decide: Once the application is complete, the PSC has 180 days to decide the case. It can extend this once, by up to another 180 days.

As of 24 September 2026, the docket showed no completeness decision and no order. ATC plans to start construction 31 days after the PSC’s written order. So construction starts on whichever date comes later: about 18 March 2027, or 31 days after the order.

What ATC has to build

ATC will build the project in two steps. Its preferred route combines the North West and South East segments. The South East segment follows the “South Alternate Route” from the first application, so the PSC can draw on the environmental review and hearing record it has already built for that route.

• The Decker interconnection: A new Decker substation next to the campus, plus short high-voltage lines that tie it into the existing grid. It takes about seven months and gives the campus partial power. ATC plans to start this work as soon as construction is authorised, and it can proceed alongside the rest of the build.
• The full project: The new lines and substations the grid needs to carry the full 1.3 GW. The whole build takes about 17 months. On the preferred South East segment, about eight months of work on the new Adell substation and the Adell–Holland line comes first, followed by about nine months converting and rebuilding existing lines. The refiled application also adds a large voltage-stabilising device (an E-STATCOM) near Decker, costed at about $1.1 billion, which smooths rapid swings in the campus’s power use.

ATC has not said how much power the first step can carry, but Vantage’s own request gives an indication of scale. In September 2025 it asked ATC to look at energising about 310 MW by the end of June 2027, using at least two of the campus’s ten main transformers. That is about the size of one of the larger buildings on our modelled allocation (see Construction progress). The same request forecast 438 MW of peak demand in 2027 and 1.3 GW from 2028 onwards, and ATC’s planning study in the refiled application uses those figures. ATC also plans to ask the regional grid operator, MISO, in October 2026 to fast-track review of the E-STATCOM. That is a separate approval to watch alongside the PSC case. Early works are also being funded ahead of approval. Under an acceleration agreement from February 2026, Vantage agreed to fund about $101.4 million of engineering, environmental, right-of-way and procurement work before any PSC order.

Our outlook

We look at three scenarios, based on when the PSC issues its written order. All three assume the application will be found complete by 19 October 2026. This is the most favourable assumption. The first application took 76 days to be found complete, after one incompleteness finding and a refiling. A similar revision in 2026 would put completeness in early December 2026 and push each date below back by about six weeks. However, we anticipate this outcome will be avoided.

(i) Earliest legal sequence. If the PSC issued its order by 15 February 2027, about four months after completeness, construction could start 31 days later, on about 18 March 2027. That is also the earliest legal date, six months after the refiling was received. Adding about seven months for the Decker interconnection gives partial power around October 2027, and adding about 17 months for the full project, per developer guidance, gives the full 1.3 GW around August 2028. This is highly unlikely. The PSC would have to decide within about four months of completeness. The fastest comparable case we reviewed, Racine County Western Feed, took more than seven months from completeness to a written order. The large 345 kV lines took about a year. ATC is also not seeking expedited review.

(ii) Base case. This case assumes the PSC decides within its first 180 days, without an extension. Counting 180 days from completeness on 19 October 2026 gives a written order around 17 April 2027, and construction would start 31 days later, around 18 May 2027. Adding about seven months for the substation gives partial power around December 2027, and the full 1.3 GW activation around October 2028. We consider this achievable because the first application was withdrawn over how ATC filed its changes, not over the project itself.

(iii) Extended review. In this scenario, the PSC invokes the 180 day extension for its final decision, as it did in every comparable large transmission case we reviewed. Four recent 345 kV lines needed a full environmental impact statement (EIS), as this one does, and all four got written orders 355 to 358 days after completeness. These were Badger Coulee, Cardinal–Hickory Creek, Grid Forward and the Western Wisconsin Transmission Connection. Here, 360 days from completeness on 19 October 2026 would give an order around 14 October 2027, and construction would start 31 days later, around 14 November 2027. Adding about seven months for the substation gives partial power around June 2028, and adding about 17 months for full construction gives 1.3 GW around April 2029. We do not treat this as the base case because this is a refiling, meaning the PSC can reuse much of the environmental review it has already completed for ATC’s preferred route. Nonetheless, if the PSC finds the new application incomplete, every date moves later still and given the PSC’s record, we do treat scenario (iii) as a real possibility rather than a remote one. This is the outcome that would push Lighthouse well outside Oracle’s guidance.

What this means for 2027

Our base case is scenario (ii). On paper, partial power in December 2027 falls just inside Oracle’s H2 2027 guidance. In practice, a data center does not enter service as soon as first grid power arrives. Each building’s electrical and cooling systems have to be energized, tested and commissioned before it can carry customer load. That will take time. We therefore expect the campus’s load to ramp up mainly from the first quarter of 2028.

The main risk is the PSC’s record on projects of similar scale and scope. Scenario (iii) and a delay of another six months would be the result if Port Washington followed the timeline of its comparable peers. Oracle is counting on the fact that most of the current refiling has already been reviewed and accepted by regulators in the previous cycle.

Similar regulatory hurdles have also been observed at other large Oracle projects, such as Project Jupiter, and they deserve to be flagged given the company’s underlying finances. We discuss this further below.

Construction progress

Vantage’s August–September update describes two buildings that are enclosed with interior work underway, and two still in structural construction. Our analysis of satellite imagery from 10 September shows more advanced roof work on WI12 and WI11, and more exposed framing and unfinished roof areas on WI13 and WI14. On current progress, we expect the buildings to be finished well before the grid can fully power them.

Left: campus electrical plan (sheet SO-E01-00). Green blocks are data modules, blue blocks are spines and red blocks are the 13 planned central utility plants. Right: Vantor satellite imagery, 10 September 2026.

No per-building MW or power-on date has been published. The MW column is our modelled allocation, derived from campus electrical plans and the utility transformer load calculation filed with the application. Overall capacity is quoted two different ways. The four halls are quoted at 902 MW of critical IT load, per the developer, and 1.3 GW of total electrical demand, per utility and environmental records. The first counts the power reaching the computing equipment, while the second counts everything the site would draw in total, including the cooling equipment.

The PSC's decision has not slowed down campus construction. Work has carried on since the completeness finding was revoked on 6 August, and Aterio’s satellite imagery shows more cooling units being installed at WI12 since then. The road to complete construction of the campus is clear. City approvals, state environmental sign-offs and the generator air permits are all in hand, and work has run continuously since December 2025.

Expansion beyond the initial four buildings

Every permit, filing and construction schedule describes four buildings drawing 1.3 GW. A larger figure of about 3.5 GW also circulates, but it is WEC’s estimate of what the site could ultimately support through future expansion, not an approved project.

The large 3.5 GW figure traces back to the land itself. The original owner of the site, Cloverleaf Infrastructure, developed a concept plan that was far bigger than today’s campus. It included 992 backup generators, against 45 for the four Lighthouse buildings. Vantage now owns that land, including 972 acres north of the current campus. Vantage still holds that option for expansion in its regulatory filings.

A load request titled for a Vantage Data Center Phase II, dated 21 October 2025, seeks full-load service by Q3 2033 for a second-phase buildout, though its MW and ramp are redacted. PSC staff testified that it could require new interconnection facilities from 2029, if the customer proceeds, but cautioned that such a request is not a firm commitment. ATC’s March 2026 responses likewise describe conditional expansion facilities from 2029 and network upgrades around 2029–2030.

A campus expansion in the early 2030s remains a possibility. Phase II has no disclosed size, no building count or no commitment behind it, and all three documents that describe it predate the August 2026 revocation. It is expected that it would need its own transmission application, which would come only after the current 1.3 GW project is decided and complete.

What to watch next

The next milestone is the PSC’s completeness decision on the refiled application, due around 19 October 2026. ATC’s October filing with MISO on the voltage-stabilising device near Decker comes at about the same time. After that, the date of the PSC’s written order sets the construction start and, thus, the partial power date. If the application is found incomplete again, or the PSC takes the full 360 days it has taken in comparable cases, partial power slips to mid-2028 and the full 1.3 GW into 2029. Once work begins, Aterio will track progress against ATC’s 7- and 17-month build schedule.

Oracle’s wider position is also worth flagging. On 24 September 2026, Oracle sent a force majeure notice to Blue Owl Capital, the developer of Project Jupiter, its Stargate campus in New Mexico. A force majeure notice is a contractual warning that events outside a party’s control may delay its obligations. The causes cited are a delayed gas pipeline and a pending air permit. Oracle says Project Jupiter remains on schedule, and the notice has no direct bearing on Port Washington. But it does show Oracle protecting itself against permitting delays on at least one other large campus.

This matters because Oracle’s finances do not leave much room for major delays on multiple campuses. Its fiscal Q1 2027 results showed a $664 billion backlog alongside negative free cash flow of about $5 billion, and S&P Global downgraded it to BBB- in July, one notch above non-investment grade. Oracle is funding its buildout largely with borrowed money and partners’ capital. Delays push revenue back while financing costs continue to accumulate and rise. At roughly 900 MW of IT load, Lighthouse is comparable in scale to the 850 MW of new capacity Oracle delivered in the last quarter. Aterio is closely monitoring this campus and will update our assessment as the PSC acts.

About the dates in this report

The dates in this report are Aterio’s own estimates, built from public regulatory filings, state law and past PSC cases. They are not commitments by ATC, the PSC, Vantage, Oracle or anyone else. Actual dates will depend on regulatory decisions, construction progress, commissioning and other factors outside the public record, and could differ materially.