The Senate Energy and Natural Resources Committee opened a two-day hearing Wednesday on the data center construction moratorium introduced last week by Senator Bernie Sanders and Representative Alexandria Ocasio-Cortez, with utility chief executives, hyperscaler representatives and grid operators offering sharply diverging accounts of whether the bill addressed an emerging power crisis or threatened to derail the country’s most strategically important industry.

The hearing began at 10 a.m. in the Dirksen Senate Office Building before a packed chamber that included representatives from every major cloud and artificial intelligence company in the United States, executives from a dozen investor-owned utilities, and a delegation of consumer advocates whose presence committee aides described as the largest assembled for a single energy hearing in more than a decade. The committee chairman opened the proceedings by acknowledging that the legislation had become “the most consequential energy and technology policy fight of this Congress” and saying the panel intended to surface “facts, not slogans, on both sides of this argument.”

The first witness, Mary-Elizabeth Konstanty, chief executive of the PJM Interconnection, the grid operator covering thirteen states and the District of Columbia, delivered testimony that several lawmakers in both parties later described as the most consequential of the day. Konstanty told the committee that data center load in the PJM footprint had grown by 38 percent over the prior eighteen months, that interconnection queue requests now exceeded 240 gigawatts of pending capacity, and that the operator could not guarantee reliable service through the summer peak of 2027 without “demand-side measures that do not currently exist in our planning toolkit.” Asked directly by Senator Sanders whether a two-year moratorium would resolve the reliability concern, Konstanty said it “would meaningfully reduce, though not eliminate,” the risk of involuntary curtailment events, and that grid operators “cannot build transmission on the timetable that AI is building load.”

Her testimony provoked an immediate response from the hyperscaler witnesses. Brian Olsavsky, the chief financial officer of Amazon, testifying on behalf of the cloud computing arm, said the company had “no quarrel with the diagnosis” offered by grid operators but objected to the moratorium as the remedy. “A moratorium is a hammer that does not distinguish between a project that brings its own generation, a project that adds none, and a project that has already broken ground,” Olsavsky said. He described the joint $42 billion infrastructure commitment announced Monday by seven hyperscaler chief executives as “real money on a real schedule” and urged senators to allow the industry “a fair chance to demonstrate that we can solve this problem without legislation that throws away two years of compute capacity.”

The clearest break with the industry came from a utility witness whose testimony surprised committee staff. James Whitcomb, the chief executive of Dominion Energy, the largest electricity provider in Virginia and the dominant utility serving the Northern Virginia data center corridor, told senators that his company supported “the principle, if not the precise mechanism, of a temporary pause on speculative data center development.” Whitcomb described an emerging two-tier interconnection problem in which “hyperscalers with executed power purchase agreements are increasingly indistinguishable, from a grid planning perspective, from speculative developers who are queue-shopping with nothing but real estate and a press release.” He suggested a moratorium scoped to projects without committed offtake or behind-the-meter generation would resolve the immediate reliability concern while preserving “responsible build-out.”

The Dominion testimony altered the tone of the hearing audibly. Ocasio-Cortez, who attended the morning session and was permitted a brief speaking turn under reciprocity rules, said the utility’s framing represented “exactly the kind of honest accounting the industry has refused to provide on its own.” A spokesperson for the hyperscaler coalition, Daniel Reeves, told reporters during a recess that Dominion’s position was “responsibly framed and worth engaging with” but did not commit the coalition to supporting any scoped version of the legislation.

Consumer advocates, testifying in the afternoon session, focused on residential electric bills. Layla Hassan, director of the Mid-Atlantic Energy Affordability Project, told the committee that average household electricity costs in Virginia had risen 31 percent over the prior two years, with similar increases reported in Ohio, Texas and Arizona. “The data centers are not paying these bills,” Hassan said. “Grandmothers in Henrico County are paying these bills. And they are paying them so that a generative video model can render a horse on a beach.” The line, captured by every news organization in the room, was widely circulated within an hour of being spoken.

The political math in the room was the subject of intense speculation. A senior aide to a moderate Democratic senator from a Mountain West state, speaking on condition of anonymity, said the hearing had “moved the needle measurably toward the bill” and that the Dominion testimony in particular had given wavering Democrats “a permission structure to support the legislation, even if it gets amended.” Two Republican senators on the committee, both representing states with concentrated grid stress, were observed taking unusually detailed notes during Konstanty’s and Whitcomb’s testimony.

Industry analysts watching the hearing offered mixed assessments. John Reilly, a technology infrastructure analyst at Citi, said the day had been “a difficult one for the hyperscalers, not because they argued poorly but because the strongest single piece of testimony came from one of their own counterparties.” He noted that shares of major data center real estate investment trusts had fallen between 2 and 4 percent during the trading session, with Equinix off 3.2 percent and Digital Realty off 2.8 percent at the close. Shares of Constellation Energy and Vistra, which had risen on Monday following the hyperscaler letter, gave back most of those gains.

The hearing continues Thursday with testimony from environmental groups, two additional utility chief executives and a panel of academic economists. The committee is expected to vote on whether to favorably report the legislation as early as next Monday, though aides cautioned that the markup schedule remained fluid. A spokesperson for the chairman, Karen Loftus, said the panel was “considering several amendments” that would narrow the bill’s scope while preserving its core demand-side intent, and said additional details would be released after the second day of testimony concluded.