CO2 capture and sequestration: an option for Switzerland?
If Switzerland decided to produce part of its electricity from gas-fired power plants, it would be technically possible to capture their CO2 emissions and store them deep underground or use them in industrial processes. But as long as the price of fossil CO2 emissions released into the air remains low, these strategies offer no profitability. A further obstacle is the growing public mistrust of CO2 sequestration.
The combustion of a fossil fuel - whether it is petrol in a car, fuel oil in a boiler, or coal or natural gas in a power plant - is a process that emits carbon dioxide (or CO2). As CO2 is a greenhouse gas, it contributes to global warming.
The technology to extract and capture CO2 from flue gases has been available since the 1930s. This CO2 could then be permanently stored, for example in sealed geological formations, usually at a depth of one kilometre. Under these conditions, the CO2 slowly reacts with the rocks and gradually turns into limestone. The process is slow, taking about 10,000 to 20,000 years. This strategy, known as CCS (carbon capture and storage), is the only technology currently available to reduce CO2 emissions from fossil fuels - apart, of course, from the possibility of no longer burning these fuels!
Because of its complexity and weight, CCS is generally not applicable to mobile emission sources, such as airplanes or cars. CCS therefore applies to stationary installations, such as coal or gas-fired power plants, or industrial plants such as cement works, which can be equipped with this technology. In theory, the potential of CCS is enormous. On a global scale, fossil fuel-fired power plants (coal, oil, gas) alone emit nearly 14 billion tonnes of CO2 each year, or about 40% of all human emissions. The magnitude of this figure highlights the critical challenge of CCS. In Switzerland there are suitable geological formations for the geological storage of CO2. If necessary, we could therefore use CCS on a large scale.
But then… if we have a powerful and mature technology to reduce CO2 emissions, why not use it? The reasons are mainly economic: CCS increases the cost of producing electricity by 50 to 90% because of the large investment required and the negative impact of CO2 capture on the energy efficiency of power plants. CCS would become profitable at an estimated CO2 emission price of between CHF 50 and 100 per tonne, i.e. above the market price in Europe, which in 2019 is around CHF 35 per tonne of CO2. In Switzerland, the CO2 tax in 2019 is CHF 96 per tonne [→ Q83], at which price CCS becomes an economically feasible option. However, operators of gas-fired power plants have the choice between paying this tax or offsetting their emissions, which is often cheaper [→ Q89].
In addition, the population appears to be increasingly reluctant to inject large quantities of CO2 below the surface, close to the regions where they live. Instead of sequestering it underground, it would theoretically be possible to use the CO2 in industrial processes for the production of fuels, fertilisers or building materials. This approach is known as carbon capture and utilisation (CCU). However, the potential of these technologies, which are currently in the development phase, is controversial within the scientific community. Given that these approaches will all consume energy, they could nevertheless prove to be relevant for using surplus renewable electricity production.
Uncertainty about the future price of carbon, the scale of the initial investment required for the technical devices, uncertainty about the CO2 recovery options and finally public concerns are thus major obstacles to the dissemination of CCS and CCU strategies. Numerous programmes are underway to verify the safety of sequestration and to lower process costs, but it will take several years to validate the results of this research. Thus, the prospects for widespread adoption of CCS or CCU remain highly uncertain, although many pilot projects exist around the world.
This being said, if the political will to drastically limit greenhouse gas emissions emerges, the CCS and CCU approaches may prove to be the only ones capable of reversing the global warming curve in the short term. Their implementation would increase fossil electricity prices and, as a result, allow renewable energies to become competitive more quickly. Against this background, it cannot be ruled out that CCS and CCU could find a viable business model in Switzerland.
- Berend & others (2014)
- Berend, S. & others (2014). Introduction to carbon capture and sequestration. World Scientific.
- European Commission (2019)
- European Commission (2019). EU emissions trading system (EU ETS). [Online]. Available at: https://ec.europa.eu/clima/policies/ets_en.
- Office fédéral de l’environnement (OFEV) (2019)
- Office fédéral de l’environnement (OFEV) (2019). Taxe sur le CO2. [Online]. Available at: www.bafu.admin.ch/bafu/fr/home/themes/climat/info-specialistes/politique-climatique/taxe-sur-le-co2.html.