Av all CO2 i Norden, er det billigst å ta hånd om den som blir med naturgassen opp fra nye gassfelt. Statoil er alt blitt internasjonalt kjent for sin lagring av CO2 fra gassfeltet Sleipner i geologiske lag under Nordsjøen. Illustrasjon: Statoil
The authors point out that Norway possesses valuable industrial experience of CO2 storage, much of which has been acquired by dealing with CO2 from the Sleipner and Snøhvit gas-fields. In this illustration, CO2 from the natural gas reservoir is taken back to the continental shelf. Illustration: Statoil

Norway should store Europe’s CO2

Opinion published 24.11.14

On Thursday October 3, Canada switched on the largest CO2-free coal-fired power station in the world. Norway could follow up.

This article first appeared in the Norwegian daily ‘Stavanger Aftenblad’ on Monday October 6, 2014.

Canada is now operating a rather special power station; the world’s largest plant that combines coal-fired electricity generation with CO2 capture and uses the CO2 for more efficient petroleum production. The plant has just opened, in the wake of the clarion call from the International Energy Agency (IEA) that renewable energy alone will not be sufficient to save our climate.

According to the IEA, if the rise in global temperature is to be kept to two degrees, the world will also have to capture and store huge amounts of CO2. Three challenges follow from this message: it is vital to start immediately; we must prioritise projects that really make a difference; and we must identify technologies that will reduce the cost of carbon capture and storage (CCS). All this suggests that Norway ought to accommodate a storage site for Europe’s CO2 on its continental shelf.

Triple gains

A large CO2 storage site on the Norwegian shelf would offer:

  • A worthwhile storage capacity: The geological formations under the North Sea are capable of storing extremely large quantities of CO2. Studies have shown that this could actually be equivalent to the amount emitted by all of the European Union’s coal- and gas-fired power stations for the remainder of the fossil fuel era. In the course of a few years we could develop a storage site capable of receiving 100 million tonnes of CO2 a year, equivalent to the emissions of 60 million cars. Even on a global scale, this would be substantial.
  • Cost savings: This storage site could be supplied via a main pipeline from the most important industrial regions in Europe. Shared by many users, such a large-scale infrastructure would offer significant operational savings. In this way, Norway could contribute to the cost-effective disposal of CO2 from a large number of European Union sources.
  • Less public opposition: The European Union has stopped almost all of its CCS pilot projects. Opposition to onshore storage of CO2 has previously contributed to the cancellation of CCS projects on the Continent. A central storage site under the sea would significantly reduce resistance of this sort. Moreover, the available storage volume is much greater than on dry land, thanks to its favourable geology.

SINTEF Petroleum Research and Christian Michelsen Research have led a study that has shown that it would be perfectly possible to locate a major CO2 storage site on the Norwegian continental shelf. There are no technical showstoppers to speak of. Familiar technology can be used, although a large-scale demonstration would be needed. The first major storage site would therefore be an important showcase for the technology.

Storage in pores

CCS is a matter of capturing and storing carbon dioxide from sources of emissions such as coal- and gas-fired power stations and industrial plants such as cement kilns and steelworks. The search for storage sites focuses on geological layers and the process is similar to exploring for oil reservoirs. In both cases, the target is porous rock-types with a “ceiling” of impermeable rock. The CO2 to be stored is injected through wells to the porous rock and into the pores that had previously held oil, gas or water.

CO2 storage beneath the seabed has been demonstrated on an industrial scale by Statoil, via projects that deal with the CO2 from Norway’s Sleipner and Snøhvit gas-fields and from the In Salah field in North Africa. In Canada, the world’s largest coal-fired power station with CCS is now operational in the Province of Saskatchewan. Most of the CO2 from this plant is stored in an oil-field and helps to improve the rate of recovery of the oil in the reservoir. The rest of the gas is stored in deep saline aquifers.

Price-tag is important

If efforts of this sort are to be implemented on a large scale, it will have to cost more to emit CO2 to the atmosphere than it does at present. It may be that the price of fossil fuel will need to double, at which point it would be equivalent to the price of energy from renewable sources.

Calculating the cost of large-scale CO2 storage would enable Norway to reduce the uncertainty surrounding the total cost of CCS. A price estimate for a common European storage site would provide an indication of how much fossil energy really ought to cost.

Among other factors, storage costs will depend on how the CO2 in the reservoir can be monitored. If it is stored using the best available reservoir technology, the risk of leaks will be low. Nevertheless, monitoring is essential, both because we need to follow the migration of the CO2 through the formation and in order to ensure that the storage potential is optimally exploited. In the event of an undesirable incident, there are a number of measures that can be taken to prevent gas leaking to the surface.

Norway possesses valuable industrial experience of CO2 storage, and has already carried out a number of research projects in the field. Furthermore, the Norwegian Petroleum Directorate and Gassnova (the state enterprise that manages the Norwegian State’s interests in relation to CCS) have acquired a great deal of knowledge regarding potential storage sites in the North Sea. All of this implies that we have an excellent point of departure for realising the idea of a major European CO2 storage site on the Norwegian continental shelf.