CO₂ By Sea: The Risky Bet Beneath Europe’s Biggest Carbon Storage Project

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Northern Lights is Europe’s most ambitious carbon capture and storage project, and possibly the most operationally serious one in the world. It deserves credit for getting past the pilot stage, for designing an end-to-end storage system with real injection capacity, and for contracting with emitters in four different countries. But it’s also revealing why so many carbon capture projects fail to scale. The answer isn’t in the geology or the chemistry.

As the first article in this series on Northern Lights laid out, capturing and storing CO₂ at industrial scale remains a technically feasible but economically fraught endeavor. Only a narrow band of emitters find CCS workable today. Those that do either produce relatively pure CO₂ streams, as in the case of Yara’s ammonia plant, or benefit from heavy government subsidies, as with the Norwegian cement and waste plants or Ørsted’s biomass plants in Denmark. Even under these best-case scenarios, capital costs often exceed €250–600 million, and levelized capture costs frequently range from €80 to €150 per ton—far above prevailing carbon prices.

The logistics and safety risks of CO₂ transport to water for the Northern Lights project add another layer of challenge. While most confirmed projects are located directly on water with port access for ship-based CO₂ export, projects like Ørsted’s Avedøre plant face costly interim trucking arrangements until a high-pressure pipeline—still facing safety, permitting, and public acceptance hurdles—can be built. The risks of dense-phase CO₂ transport, vividly demonstrated by the 2020 pipeline rupture in Satartia, Mississippi, are not hypothetical, particularly in densely populated Europe. Each project must incorporate expensive safety systems, buffer storage, and rigorous monitoring.

The second part of the answer is from the water to the sequestration site. From the beginning, Northern Lights has relied entirely on marine transport. There are no long pipelines. There is no cross-border network. There is only the sea. Every emitter liquefies CO₂ at their facility, stores it temporarily in buffer tanks, and then loads it onto a ship that carries it to Øygarden, on the west coast of Norway. There, the CO₂ is transferred to shore tanks, compressed again, and piped offshore to a saline aquifer more than two kilometers below the seabed. It is, from an engineering perspective, brilliant. Every component is engineered to high safety standards. The injection formation is well-characterized. The liquefaction is industrial grade. The compression and measurement equipment is state of the art. The missing element is a good reason to do this instead of better alternatives like avoiding emitting CO2 in the first place.

Phase 1 is still under construction. It includes the Øygarden terminal, injection wellhead, and a short subsea pipeline to the storage formation. It also includes a pair of 7,500 m³ liquefied CO₂ ships, initially, with two more joining in a year. These vessels are custom-built with pressurized, cryogenic tanks, LNG-fueled propulsion systems, and wind-assisted rotor sails. Each can carry roughly 6,500 to 7,000 tons of CO₂ per voyage. The Phase 1 customers—Heidelberg Materials, Hafslund Celsio, Yara International, Ørsted—will together send about 1.5 million tons of CO₂ annually. On most legs, the distances are modest: Brevik and Oslo are both within 350 nautical miles of Øygarden. Sluiskil, in the Netherlands, is longer—around 700 nautical miles. Each voyage takes several days, and with a small fleet, that means careful scheduling. There is limited room for error. If a ship is delayed, CO₂ backs up at the emitter site. If the Øygarden tanks are full or under maintenance, the ship waits, burning fuel.

They are making every effort to make these ships low-carbon. They are slow-steaming. They are using hull-bubblers to reduce hull friction. The Magnus-effect rotors work, and thankfully they are only claiming that they make the ship a few percentage points more efficient for specific conditions, instead of pretending that they are a massive win. Norway does love its Flettner rotors for some reason, despite neither Flettner, the engineer who invented them, nor Magus, the physicist who discovered the effect, being German.

The LNG part is mixed. Norwegian natural gas comes from a system engineered to avoid leakage and other emissions, unlike US natural gas. As a result, upstream emissions are low. And it does burn with lower CO2 emissions than bunker fuel. But the maritime shipping fuel regulations related to greenhouse gas emissions currently don’t require methane slippage from maritime engines be taken into account, and as the International Council on Clean Transportation (ICCT) Fugitive Unburnt Emissions from Shipping (FUMES) report from a couple of years ago made clear, it was about double what the industry thought it was, raising LNG burning engines above bunker fuel in full lifecycle greenhouse gas emissions.

Will the ships actually be lower emissions than simpler, cheaper ones that burn bunker fuel? Hard to say, but they won’t be as much of a win as is claimed. That said, greenhouse gas emissions without methane slippage are in the 2-3% of transported, and with slippage might be 5%, so if the entire system made sense, this would be reasonable. And there are further levers to pull on shipping fuels.

With capital costs of these new, complex and high-tech ships, maintenance and operations, just transporting the CO2 from dock to dock adds around €30 to the cost.

Phase 2 is more ambitious. It is intended to more than triple annual volumes to 5 million tons. It adds Stockholm Exergi to the customer base, but no other confirmed ones, making phase 2 look increasingly unlikely as potential clients like BASF back away. The emitters are expected to be further afield. Stockholm to Øygarden is nearly 2,000 kilometers round trip. The ships get larger—12,500 to 20,000 m³—and more numerous. The propulsion remains LNG-based, with per-voyage fuel consumption in the range of 80 to 130 tons of LNG depending on the route and speed. That fuel is efficient by maritime standards, but still emits between 2.7 and 3 tons of CO₂ per ton burned. By the time Phase 2 is operating at full volume, the shipping segment alone will emit 30,000 to 50,000 tons of CO₂ per year. That’s two to three percent of the very carbon the system is being built to remove.

That wouldn’t be a deal-breaker—many climate systems involve embedded emissions—if the alternative were more expensive or less reliable. But that’s the issue. The alternative isn’t hypothetical. It’s pipelines. And for all of Phase 2’s engineering strength, there is still no pipeline in the plan. Every emitter is building their own liquefaction and storage infrastructure. Every port needs its own loadout arms and cryogenic tanks. Øygarden needs to offload, buffer, and inject five million tons per year, in cadence with ship arrivals. There is no aggregation point. No trunkline. No resilience beyond scheduling and redundancy.

This was one of the factors that pushed Yara to reconsider its long-term strategy. The Sluiskil site is well-positioned for direct ship loading, and the initial investment was justified by timing and availability. But as Dutch pipeline-connected storage projects like Porthos and Aramis advance, the economic case for marine transport becomes harder to defend. A pipeline doesn’t stop for weather. It doesn’t need to berth. It doesn’t emit. Once it’s in the ground and under the sea, it moves CO₂ continuously, at high capacity, for decades. And once emitters begin comparing lifecycle costs—not just of transport, but of buffer tanks, liquefiers, compressor maintenance, and carbon allowance exposure—the pipeline wins. Compression and transportation are expected to be €12 to €30 per ton, well under the combination of buffering storage, liquefaction and shipping. This still isn’t particularly cheap as it is just for moving the waste gas around. It still has to be captured and cleaned at the point of emission and then has to be managed and injected at the sequestration site, both of which add significant costs. And sequestration sites fill up, so pipeline capital costs can become challenging to justify.

Yara hasn’t made an official break. Their contract with Northern Lights remains. But their growing engagement with Dutch pipeline projects is telling. The underlying message is that shipping is viable, but it is not permanent. It is what you do before you have a network. It’s what you use to buy time.

Northern Lights, to its credit, has pushed the envelope. It has brought together governments, emitters, and oil majors in a project that will operate at real industrial scale, although it remains to be seen if even its current customers will stay loyal. That’s more than most CCS efforts ever achieve. But the transport system is expensive, complex, and vulnerable to disruption. It works only if every link in the chain—compression, liquefaction, buffer, shipping, offload, reinjection—functions without delay. The margin for error is measured in hours.

Of course, the ships are part of the 80% of capital costs that Norway is paying for out of its sovereign wealth fund in an effort to stay relevant in a world that won’t want its natural gas and certainly won’t want its hydrogen for energy in the future. But even after 80% of the capital cost is taken care of, the shipping costs €30 per ton for a homeopathic 1.5 million tons a year, much of which should have been avoided by actually decarbonizing the processes instead through electrification, alternative processes and biogenic feedstocks. That’s what should be being subsidized, not ships plying long North Sea routes through stormy weather full of CO2.

The next article will deal with the sequestration site and its challenges and costs. Stay tuned for more bad news for CCS.