Europe’s first offshore CO2 storage site

November 27, 2025

What begins as a tiny speck on the North Sea horizon gradually transforms into the isolated Nini oil field, a long-standing industrial outpost accessible only by helicopter. Once dedicated to pumping fossil fuels from beneath Europe’s rugged seabed, the site is now being transformed into a pioneering hub for offshore carbon storage.

Instead of extracting oil, chemical company INEOS plans to send liquefied carbon dioxide back into the Earth—injecting it nearly 1,800 meters below the surface into depleted oil reservoirs. The process effectively reverses decades of oil production and marks a major leap forward for Europe’s carbon capture and storage (CCS) ambitions.

During a rare visit to the Siri platform—located near the unmanned Nini site—The Associated Press observed the final phase of Project Greensand Future, INEOS’ flagship CCS initiative. When the project enters full commercial operation next year, it is expected to become the European Union’s first fully operational offshore CO2 storage facility.

Environmental experts acknowledge that CCS can contribute to climate mitigation, but they warn it must not become a loophole allowing industries to keep polluting instead of cutting emissions.

Scaling up: INEOS’ future CCS plans

According to Mads Gade, CEO of INEOS Energy Europe, the company will initially store around 363,000 metric tons of CO2 per year, with plans to expand capacity to 7.3 million metric tons annually by 2030.

“Denmark has the ability to store several hundred years’ worth of its own emissions,” Gade explained. “This creates an entirely new industry, one that can help Europe safely store significant volumes of CO2.”

To supply the captured carbon, Greensand has already secured agreements with Danish biogas producers. A dedicated CO2 terminal is under construction at the Port of Esbjerg, and a new transport ship—named Carbon Destroyer 1—is being built in the Netherlands for continuous CO2 delivery.

A potential climate solution

Supporters of carbon capture technology argue that CCS is an essential tool for removing heat-trapping gases from the atmosphere and locking them away underground. The Intergovernmental Panel on Climate Change (IPCC) also recognizes CO2 storage as a crucial component of global climate strategies.

In line with its climate targets, the European Union aims to scale up to at least 227 million metric tons of CO2 storage capacity per year by 2040, helping meet its 2050 net-zero goal.

Gade emphasizes that CCS is one of the most effective ways to cut emissions while protecting industrial jobs. “We don’t want to deindustrialize Europe. We need practical solutions that decarbonize without shutting everything down.”

Geological experts at the Geological Survey of Denmark and Greenland confirm that the sandstone formations in the Greensand area are ideal for CO2 storage. Senior researcher Niels Schovsbo highlights that the rock layers contain millions of tiny pores capable of safely trapping liquefied CO2. The overlying seal rock adds an additional layer of protection.

“These two factors make Greensand an excellent site for permanent CO2 storage,” Schovsbo said.

Concerns and criticism

Despite growing enthusiasm, CCS technology remains limited in scale worldwide. Many facilities still rely on fossil fuels to power their operations, and current global CCS efforts capture only a tiny portion of the 34.5 billion metric tons of CO2 emitted globally last year, according to the International Energy Agency.

Environmental groups argue that carbon capture is often used to justify delaying meaningful emissions reductions.

“CCS should be reserved for sectors where emissions are truly unavoidable,” said Helene Hagel, climate policy lead at Greenpeace Denmark. “The problem arises when every industry claims it can simply capture and store emissions instead of reducing them.”

Even as INEOS advances its carbon storage initiatives, the company is also exploring development of a new North Sea oil field. Gade says this is necessary for Europe’s energy transition.

“Producing regional oil and gas locally has a far smaller footprint than importing high-emission energy,” he said. “We see this as a temporary but important step while Europe transitions to cleaner solutions.”