29 March 2007
Prospective Scenarios for Renewable Energies and Carbon Capture and Storage
A German team of scientists has recently compared the structural, economic and
environmental aspects of carbon capture and storage (CCS) with renewable energy
technologies. Even if CCS technologies emit more carbon dioxide than generally assumed
and considerably more than renewables, CCS could lead to a significant absolute reduction
of greenhouse gas emissions within the electricity supply system. However, depending on
market forces, renewables could develop faster and become cheaper.
The use of fossil fuels and especially coal in power generation is responsible for major carbon dioxide (CO2)
emissions. As CO2 is a greenhouse gas that contributes to climate change, it is crucial to mitigate
anthropogenic emissions of this gas. Increasing the use of renewable energies is one alternative, however,
coal is among the most abundant fossil fuels and consequently active research is ongoing in order to find
solutions to use it in a more environment-friendly fashion. In this regard, capturing and storing the CO2
generated during the combustion of coal in underground geological reservoirs is a very attractive solution. At
present there are still questions regarding safety, feasibility, as well as ecological and economic implications of
CCS. Nevertheless, it is of significant importance to assess how CCS and renewable energies could coexist in
the near future and what the consequences in term of competitiveness, environmental benefits and market
structure would be.
Prospective scenarios were assessed following a life cycle analysis methodology which consisted in
analysing resource consumption and emissions occurring during the whole life cycle of such a power
plant; from the extraction of raw materials, their transport and processing, building and using the plant
and then dismantling and final disposal. The authors chose a reference year of 2020, when the first
power plant including CCS is expected to start operation in Germany. The authors modelled the
changes in fossil fuel price and costs of CCS and renewables with different lower and upper parameters
to cover best and worst case scenarios. Power plants equipped with the three most common CCS
technologies were then compared to wind offshore plants and solar thermal plants in case of LCA and
to wind and a mix of renewables for the cost assessment. Their results are as follows:
• When CCS is fitted, plants require additional energy consumption of 23%-40%. Although CO2 from stack in
power plants equipped with CCS is reduced by up to 88%, if the whole life cycle is considered, this figure may
fall to a 72% reduction. If all greenhouse gases are considered, CCS gives a reduction of from 65% to 79%. In
comparison, renewable electricity emits only 1%-4% of the GHG emitted by CCS-plants when their entire life
cycles are considered.
• CCS development depends on fuel price evolution. Based on a worldwide ambitious advancement and
diffusion of renewable energies, CCS would not be competitive against renewables if CO2 emission permits
are below 35€/t in 2050. Depending on the growth rates and market developments, renewables could
develop faster and become cheaper than CCS-plants in the long term (from 2020 in case of wind energy and
from 2030 considering a mix of renewables).
• CCS might yet not be available when Germany phases out most of its fossil fuel plants within the next 15
years. CCS would be beneficial only if capture-ready plants are built and retrofitted by 2020. In that case a CO2
reduction of 80% in the year 2050 could be achieved.
The authors conclude that even if there are many uncertainties in the scenarios that have been considered, these results
show one possible development path under specific assumptions considered as the most likely ones.
Many hypotheses specific to Germany were put forward in this study and results cannot be extrapolated directly
elsewhere. However, this study confirms that technically both CCS and renewable technologies could play an important
role in greenhouse gas mitigation, the proportion of each being mostly driven by market forces and country specific
contexts.
Source: Viebahn P. et al. (2007) "Comparison of carbon capture and storage with renewable energies technologies regarding
structural, economic, and ecological aspects in Germany", International Journal Of Greenhouse Gas Control, doi:10.1016/S17505836(07)00024-2
Contact: [email protected]
Theme(s): Environmental technologies, climate change and energy
Opinions expressed in this News Alert do not necessarily reflect those of the European Commission
To cite this article/service: "Science for Environment policy": European Commission DG Environment News Alert Service, edited by
BIO Intelligence Service.
European Commission DG ENV
News Alert issue 60
March 2007
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