A company called DeepGreen Cook Inlet is seeking a federal permit to install a tidally powered data center in the Forelands region near Nikiski. Until November 2, the Federal Energy Regulatory Commission (FERC) will accept public comments on the data center proposal.
Cook Inletkeeper will be submitting both comments and a motion to intervene. FERC has already received nearly 40 comments on the project from individuals—most, if not all, opposing it—and motions to intervene from the Kenai Peninsula Borough, the Center for Biological Diversity, and the Alaska Commercial Fisheries Conservation Alliance.
The potential impacts of DeepGreen’s proposal are full of questions, because underwater data centers are a novel concept. The chief selling point is passive cooling from the surrounding seawater, reducing or eliminating the energy-intensive need to dissipate the massive amounts of waste heat produced by computation. Microsoft ran a small experimental one in Scotland from 2018 to 2020 and confirmed in 2024 that they don’t plan to pursue the project further. This spring, a Chinese telecom company installed an underwater data center beneath a platform off the coast of Shanghai. With 24 megawatts of power consumption, the Shanghai data center would be considered a medium-scale facility—in contrast to the roughly 100-megawatt “hyperscale” data center that DeepGreen wants to put under Cook Inlet.
As a novel concept, underwater data centers will likely have novel problems—especially in the turbulent and ecologically important waters of Cook Inlet. We’ll be pushing for FERC to require sound science rather than techno-hype in its judgment of the project. Ultimately, a hyperscale underwater data center is something our region can live without.
The description of the data center that’s become public via Federal Energy Regulatory Commission (FERC) filings is vague, and the developer’s design may not be very far along. But based on what we know presently, here are a few of the novel problems FERC should investigate.
Hydroacoustic noise from tidal generators
According to its FERC filing, DeepGreen’s installation would be powered by between 330 and 350 tidal turbine generators, of the “best available technology.” Elsewhere in the application, DeepGreen told FERC that the data center will be designed to work with turbines made by Ocean Renewable Power Corporation (ORPC), the tidal power startup planning a pilot project in a nearby part of the Forelands. Though DeepGreen’s description of the turbines matches ORPC’s “TidGen” model, an ORPC representative told Inletkeeper that, as of early September, ORPC has had no involvement in DeepGreen’s FERC application “or related activities.”
Inletkeeper supports ORPC’s proposed American Tidal Energy Project, which would install 1-5 megawatts of tidal generation in the Forelands as a pilot program. At most, this would be equivalent to five of ORPC’s one-megawatt TidGen units. We hope the project is successful and can scale up to a reliable source of renewable power for the people of Cook Inlet. However, the scale of tidal power that Inletkeeper could support likely lies somewhere between five turbines and three hundred. We can’t say exactly where that limit is until actual turbines — either ORPC’s or some other company’s — are tested in the environment of Cook Inlet, creating an opportunity to understand the extent and impact of the noise they produce. We want tidal power with limited impact, scaled appropriately to local needs. Starting small and scaling up is the way to do tidal power right.
Water warming impacts
An underwater data center’s chief selling point is the ability to passively dispel its waste heat into a cold sea. DeepGreen’s description of its “computer hives” includes a passive cooling system that rejects heat via copper-nickel alloy cooling fins on the outside of the cylindrical hulls containing the computing equipment. Computation converts roughly 100 percent of its energy input into waste heat. DeepGreen is planning a 100 megawatt data center, which would release about 876 gigawatt-hours of thermal energy per year if it runs constantly.
A big ocean can, of course, absorb far more heat than that. But the Forelands is a narrow bottleneck of Cook Inlet, through which salmon runs going into the Susitna and other rivers of the northern watershed will need to pass. Whether the data center has the potential to create a warm-water plume in this relatively confined and important area, and whether this would affect the health or behavior of salmon, plankton, or other marine life is an unknown that should merit serious analysis.
Copper pollution
In addition to waste heat, the fact that the cooling system would include copper-nickel cooling fins directly exposed to seawater, strong currents, and silt might be an area of concern itself. Even small amounts of copper can be toxic to salmon.
Though DeepGreen proposes to use a type of copper-nickel alloy common in plumbing for seawater cooling, FERC should require them to study the concentration of copper particles it could release under conditions in the Forelands, where it would be exposed to high currents carrying a heavy load of fine silt, while subject to the thermal stress of releasing the data center’s waste heat. Chemical oceanographers and marine toxicologists should assess how serious the data center’s copper pollution could be.
The communities of Cook Inlet | Tikahtnu deserve thoughtful, sustainable solutions that truly serve local needs. Rather than prioritizing massive, energy-intensive data centers, we should focus on projects that deliver reliable, renewable energy and protect the region’s salmon and ecosystems for future generations.
How to submit a public comment
1. Click on the link below & accept the warning it gives you
https://ferconline.ferc.gov/QuickComment.aspx
2. Fill out your information
3. Prewrite your public comment so you can copy & paste it
4. Check your email for eFiling@ferc.gov
5. Click that link to comment
6. Put in the docket number P-15423-000
7. Copy & paste your comment
8. Submit