1.2 The role of CCS
CCS has a key role amongst a portfolio of emission reductions technologies. The IEA (2012b) has developed scenarios to examine pathways to achieve energy emission reductions under a range of assumptions. Central to the changes required to cut energy-related CO2 emissions in half by 2050 are three key strategies:
- creation of a smarter, more flexible, decentralised energy system;
- improved energy efficiency; and
- transformation of electricity generation.
The first two items directly target decoupling of energy consumption and economic activity in seeking to use a wider variety of energy providers and to do so in both technologically and behaviourally more efficient ways. But it is the decarbonisation of the electricity system by 2050 that is the most important technological change required, and here CCS has a fundamental role, together with renewable and nuclear technologies.
CCS is the only technology currently available or on the horizon (later this century) that can decarbonise sectors such as cement, or iron and steel. The IEA notes that emission reductions in these sectors need to commence shortly, but complete decarbonisation will require increased penetration of the use of electricity into these sectors (as well as transport), reinforcing the importance of the technological transformation of electricity generation in the first place.
In order to decarbonise electricity generation by 2050, as well as making significant progress in decarbonising industrial emissions, the IEA identified the portfolio of low-carbon technologies required to achieve this at least cost (Figure 6). In the absence of countries implementing further climate change policies, energy-related emissions could nearly double from 31.5 Gt in 2009 to 58 Gt by 2050. Reducing energy-related emissions to 16 Gt by 2050 requires large investments in CCS and in renewable and nuclear technologies, as well as significant, but achievable, improvements in energy efficiency.
FIGURE 6 Energy-related CO2 emission reductions by technology
Source: IEA (2012b).
Note: Percentages represent share of cumulative emissions reductions to 2050. Percentages in brackets represent share of emissions reductions in the year 2050.
The scenario that incurs the lowest overall cost identifies CCS accounting for 14 per cent of the total 850 Gt reduction in energy-related CO2 emissions by 2050. The total amount of CO2 sequestered by CCS technologies through to 2050 in this scenario is around 123 Gt, with 70 per cent captured from the power sector and 30 per cent from industrial applications such as gas processing, fertiliser production and cement manufacture. However, as electricity generation must be decarbonised by 2050, the growth of CCS in this sector slows towards the end of this period, whereas CCS activities continue to increase in the industrial sector (Figure 7). Overall, the role of CCS grows over time as the required reduction in total CO2 emission increases, requiring increasing action in the industrial sector.
FIGURE 7 CO2 capture by sector and region
Source: IEA (2012b).
By 2050, the role of CCS in decarbonising energy emissions is evenly split between capturing emissions in the power sector and in industry. Although the deployment of CCS occurs in Organisation for Economic Co-operation and Development (OECD) member countries initially, it is non-OECD countries where CCS has a larger role. This is because these countries experience higher rates of economic growth with development over the long term and as industrial activities in particular increase at a much faster rate in those countries. By 2050, in the scenarios modelled by the IEA, non-OECD countries should account for 70 per cent of CO2 captured and stored securely.
If CCS were to be excluded as a technology option in the electricity sector, the IEA states that investment costs over the period would increase by 40 per cent, or approximately US$3 trillion, because they will draw on relatively more expensive abatement options to provide electricity. Minimising the resources required to reduce emissions makes it easier and more affordable for all countries to undertake the task, including developing economies. Importantly, it means more resources for other key social and economic tasks such as improving health outcomes, developing skills, and reducing poverty.
As CCS is currently the only technology available to support the complete decarbonisation of the production of industrial products such as iron and steel or cement, if it were not available to these sectors then it is unclear whether industrial use of energy could be completely decarbonised at all.