First Dedicated Nuclear-Powered Mining Site Goes Live in Pennsylvania

Cumulus Data, a subsidiary of Talen Energy, announced on Thursday that it had energized a 280-megawatt Bitcoin mining operation drawing power directly from the Susquehanna nuclear generating station in Pennsylvania. The site is the first U.S. mining operation of meaningful scale to use a behind-the-meter power arrangement with a nuclear plant, bypassing the wholesale market and the associated transmission charges.

Why behind-the-meter matters

In a conventional mining operation, electricity is purchased from the wholesale market at a price that includes generation cost, transmission cost, and grid service fees. The all-in cost typically runs $0.045-0.070 per kWh in U.S. markets. Behind-the-meter arrangements, where the load is co-located with the generator and does not use the transmission grid, can deliver power at the generator's marginal cost plus a modest margin — in the case of nuclear, approximately $0.022-0.028 per kWh.

The economics are substantial. At Cumulus's 280 MW load and an assumed $0.020 per kWh cost advantage versus wholesale, the site captures approximately $49 million per year in power cost savings relative to a comparable grid-connected operation.

"The regulatory path for behind-the-meter nuclear has been unclear for years. We spent two years working with FERC and PJM to get the model approved." — Mac McFarland, president and CEO, Talen

The regulatory path

The Federal Energy Regulatory Commission approved Talen's behind-the-meter arrangement in a 3-2 decision in late 2025, over objections from PJM, the grid operator. PJM's objection was that large loads connected behind the meter at generators reduce the generator's contribution to grid reliability services, and that this reduction is not adequately priced in the current market structure.

FERC's majority held that the reliability concerns could be addressed through targeted tariff adjustments rather than by blocking the arrangement entirely. The minority, led by Commissioner Danly, dissented on the basis that the arrangement created a precedent that would be difficult to manage at scale.

The pipeline

Talen's site is the first of several behind-the-meter nuclear mining arrangements that are in various stages of development:

• Constellation Energy: evaluating sites at Byron and Braidwood in Illinois
• Vistra: discussing options at Comanche Peak in Texas
• Dominion Energy: early-stage discussions for North Anna in Virginia

If all three proceed, the U.S. nuclear fleet could be hosting approximately 1.5-2 gigawatts of mining capacity by 2028. That would be a meaningful share of both the national mining capacity and, more notably, the nuclear fleet's marginal load.

The climate-angle framing

A number of commentators have pointed out that mining's use of nuclear baseload power is, on net, positive for the economics of nuclear generation. Nuclear plants have high fixed costs and low marginal costs, and they run best at steady high utilization. Mining, which provides continuous baseload demand, helps maintain the economic viability of the plants that host it. If the plant would otherwise be marginal, the mining load is arguably climate-positive insofar as it extends the operational life of a zero-carbon generating asset.

Whether this framing persuades the environmental organizations that have been generally critical of Bitcoin mining is a separate question. The quantitative case is there. The political case remains contested.