On sustainability of bioenergy production: Integrating co-emissions from agricultural intensification

Biomass from cellulosic bioenergy crops is seen as a substantial part of future energy systems, especially if climate policy aims at stabilizing CO₂ concentration at low levels. However, among other concerns of sustainability, the large-scale use of bioenergy is controversial because it is hypothesized to increase the competition for land and therefore raise N₂O emissions from agricultural soils due to intensification. We apply a global land-use model that is suited to assess agricultural non-CO₂ GHG emissions. First, we describe how fertilization of cellulosic bioenergy crops and associated N₂O emissions are implemented in the land-use model and how future bioenergy demand is derived by an energy-economy-climate model. We then assess regional N₂O emissions from the soil due to large-scale bioenergy application, the expansion of cropland and the importance of technological change for dedicated bioenergy crops. Finally, we compare simulated N₂O emissions from the agricultural sector with CO₂ emissions from the energy sector to investigate the real contribution of bioenergy for low stabilization scenarios.As a result, we find that N₂O emissions due to energy crop production are a minor factor. Nevertheless, these co-emissions can be significant for the option of removing CO₂ from the atmosphere (by combining bioenergy use with carbon capture and storage (CCS) options) possibly needed at the end of the century for climate mitigation. Furthermore, our assessment shows that bioenergy crops will occupy large shares of available cropland and will require high rates of technological change at additional costs.     

Cost-effective policy instruments for greenhouse gas emission reduction and fossil fuel substitution through bioenergy production in Austria

Climate change mitigation and security of energy supply are important targets of Austrian energy policy. Bioenergy production based on resources from agriculture and forestry is an important option for attaining these targets. To increase the share of bioenergy in the energy supply, supporting policy instruments are necessary. The cost-effectiveness of these instruments in attaining policy targets depends on the availability of bioenergy technologies. Advanced technologies such as second-generation biofuels, biomass gasification for power production, and bioenergy with carbon capture and storage (BECCS) will likely change the performance of policy instruments. This article assesses the cost-effectiveness of energy policy instruments, considering new bioenergy technologies for the year 2030, with respect to greenhouse gas emission (GHG) reduction and fossil fuel substitution. Instruments that directly subsidize bioenergy are compared with instruments that aim at reducing GHG emissions. A spatially explicit modeling approach is used to account for biomass supply and energy distribution costs in Austria. Results indicate that a carbon tax performs cost-effectively with respect to both policy targets if BECCS is not available. However, the availability of BECCS creates a trade-off between GHG emission reduction and fossil fuel substitution. Biofuel blending obligations are costly in terms of attaining the policy targets.     

Determinants of the costs of carbon capture and sequestration for expanding electricity generation capacity

This study models the costs of electricity generation with carbon capture and sequestration (CCS), from generation at the power plant to carbon injection at the reservoir, examining the economic factors that affect technology choice and CCS costs at the individual plant level. The results suggest that natural gas and coal prices have profound impacts on the carbon price needed to induce CCS. To extend previous analyses we develop a "cost region" graph that models technology choice as a function of carbon and fuel prices. Generally, the least-cost technology at low carbon prices is pulverized coal, while intermediate carbon prices favor natural gas technologies and high carbon prices favor coal gasification with capture. However, the specific carbon prices at which these transitions occur is largely determined by the price of natural gas. For instance, the CCS-justifying carbon price ranges from $27/t CO₂ at high natural gas prices to $54/t CO₂ at low natural gas prices. This result has important implications for potential climate change legislation. The capital costs of the generation and CO₂ capture plant are also highly important, while pipeline distance and criteria pollutant control are less significant.     

Carbon-negative biofuels

Current Kyoto-based approaches to reducing the earth's greenhouse gas problem involve looking for ways to reduce emissions. But these are palliative at best, and at worst will allow the problem to get out of hand. It is only through sequestration of atmospheric carbon that the problem can be solved. Carbon-negative biofuels represent the first potentially huge assault on the problem, in ways that are already technically feasible and practicable. The key to carbon negativity is to see it not as technically determined but as an issue of strategic choice, whereby farmers and fuel producers can decide how much carbon to return to the soil. Biochar amendment to the soil not only sequesters carbon but also enhances the fertility and vitality of the soil. The time is approaching when biofuels will be carbon negative by definition, and, as such, they will sweep away existing debates over their contribution to the solution of global warming.     

Strategy for promoting low-carbon technology transfer to developing countries: The case of CCS

Carbon Capture and Storage (CCS) is the critical enabling technology that would reduce CO₂ emissions significantly while also allowing fossil fuels to meet the world’s pressing energy needs. The International Energy Agency analysis shows that although the developed world must lead the CCS effort in the next decade, there is an urgent need to spread CCS to the developing world. Given technologies for reducing GHG emissions originate mainly in developed countries, technology transfer, as an important feature emphasized by both the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol, therefore has a key role to play in bridging a gap between developed and developing countries. The main objective of this paper is to explore potential policies and schemes promoting the transfer of CCS technologies to developing countries. First, it reviews the global CCS status, analyzes the significant gap of CCS in developed and developing countries, and investigates stakeholder perceptions of diffusing CCS to China, which is a major developing country and a significant potential candidate for large-scale CCS deployment; then the authors make an attempt to understand technology transfer including its benefits, barriers, and definition. The UNFCCC explicitly commits the developed (Annex I) countries to provide financial and technical support to developing countries under favorable terms. The authors argue that the ultimate goal of technology transfer should not only be limited to apply CCS in developing countries, but also to enhance their endogenous capabilities, which will enable future innovation and ensure long-term adoption of low-carbon technologies. As a result, the authors propose a four-pronged approach to the transfer of CCS technologies, which involves physical transfer of explicit technologies, a financial mechanism, endogenous capacity building, and a monitoring mechanism. Concrete enhanced actions to promote CCS technology transfer are also proposed. The four-pronged approach and related enhanced actions proposed in this paper are also applicable to other low-carbon technology transfer.     

Techno-economic evaluation of coal-to-liquids (CTL) plants with carbon capture and sequestration

Coal-to-liquids (CTL) processes that generate synthetic liquid fuels from coal are of increasing interest in light of the substantial rise in world oil prices in recent years. A major concern, however, is the large emissions of CO₂ from the process, which would add to the burden of atmospheric greenhouse gases. To assess the options, impacts and costs of controlling CO₂ emissions from a CTL plant, a comprehensive techno-economic assessment model of CTL plants has been developed, capable of incorporating technology options for carbon capture and storage (CCS). The model was used to study the performance and cost of a liquids-only plant as well as a co-production plant, which produces both liquids and electricity. The effect of uncertainty and variability of key parameters on the cost of liquids production was quantified, as were the effects of alternative carbon constraints such as choice of CCS technology and the effective price (or tax) on CO₂ emissions imposed by a climate regulatory policy. The efficiency and CO₂ emissions from a co-production plant also were compared to the separate production of liquid fuels and electricity. The results for a 50,000 barrels/day case study plant are presented.     

The calcium looping cycle for large-scale CO2 capture

The reversible reaction between CaO and CO₂ is an extremely promising method of removing CO₂ from the exhaust of a power station, generating a pure stream of CO₂ ready for geological sequestration. The technology has attracted a great deal of attention recently, owing to a number of its advantages: the relatively small efficiency penalty which it imposes upon a power station (estimated at 6–8 percentage points, including compression of the CO₂); its potential use in large-scale circulating fluidised beds (a mature technology, as opposed to the vastly upscaled solvent scrubbing towers which would be required for amine scrubbing); its excellent opportunity for integration with cement manufacture (potentially decarbonising both industries) and its extremely cheap sorbent (crushed limestone).     

The cost of integration of zero emission power plants—A case study for the island of Cyprus

In this work, a technical, economic and environmental analysis is carried out for the estimation of the optimal option scenario for the Cyprus's future power generation system. A range of power generation technologies integrated with carbon capture and storage (CCS) were examined as candidate options and compared with the business as usual scenario. Based on the input data and the assumptions made, the simulations indicated that the integrated gasification combined cycle (IGCC) technology with pre-combustion CCS integration is the least cost option for the future expansion of the power generation system. In particular, the results showed that for a natural gas price of 7.9US$/GJ the IGCC technology with pre-combustion CCS integration is the most economical choice, closely followed by the pulverized coal technology with post-combustion CCS integration. The combined cycle technology can, also, be considered as alternative competitive technology. The combined cycle technologies with pre- or post-combustion CCS integration yield more expensive electricity unit cost. In addition, a sensitivity analysis has been also carried out in order to examine the effect of the natural gas price on the optimum planning. For natural gas prices greater than 6.4US$/GJ the least cost option is the use of IGCC technology with CCS integration. It can be concluded that the Cyprus's power generation system can be shifted slowly towards the utilization of CCS technologies in favor of the existing steam power plants in order not only to lower the environmental emissions and fulfilling the recent European Union Energy Package requirements but also to reduce the associated electricity unit cost.     

Greenhouse gas mitigation in a carbon constrained world: The role of carbon capture and storage

Carbon capture and storage (CCS) promises to allow for low-emissions fossil-fuel-based power generation. The technology is under development; a number of technological, economic, environmental and safety issues remain to be solved. CCS may prolong the prevailing coal-to-electricity regime and countervail efforts in other mitigation categories. Given the need to continue using fossil-fuels for some time, however, it may also serve as a bridging technology towards a renewable energy future. In this paper, we analyze the structural characteristics of the CCS innovation system and perform an energy-environment-economic analysis of the potential contribution of CCS, using a general equilibrium model for Germany. We show that a given climate target can be achieved at lower marginal costs when the option of CCS is included into the mix of mitigation options. We conclude that, given an appropriate legal and policy framework, CCS, energy efficiency and some other mitigation efforts are complementary measures and should form part of a broad mix of measures required for a successful CO₂ mitigation strategy.     

Carbon capture and storage as a corporate technology strategy challenge

Latest estimates suggest that widespread deployment of carbon capture and storage (CCS) could account for up to one-fifth of the needed global reduction in CO₂ emissions by 2050. Governments are attempting to stimulate investments in CCS technology both directly through subsidizing demonstration projects, and indirectly through developing price incentives in carbon markets. Yet, corporate decision-makers are finding CCS investments challenging. Common explanations for delay in corporate CCS investments include operational concerns such as the high cost of capture technologies, technological uncertainties in integrated CCS systems and underdeveloped regulatory and liability regimes. In this paper, we place corporate CCS adoption decisions within a technology strategy perspective. We diagnose four underlying characteristics of the strategic CCS technology adoption decision that present unusual challenges for decision-makers: such investments are precautionary, sustaining, cumulative and situated. Understanding CCS as a corporate technology strategy challenge can help us move beyond the usual list of operational barriers to CCS and make public policy recommendations to help overcome them.     

A scalable infrastructure model for carbon capture and storage: SimCCS

In the carbon capture and storage (CCS) process, CO₂ sources and geologic reservoirs may be widely spatially dispersed and need to be connected through a dedicated CO₂ pipeline network. We introduce a scalable infrastructure model for CCS (simCCS) that generates a fully integrated, cost-minimizing CCS system. SimCCS determines where and how much CO₂ to capture and store, and where to build and connect pipelines of different sizes, in order to minimize the combined annualized costs of sequestering a given amount of CO₂. SimCCS is able to aggregate CO₂ flows between sources and reservoirs into trunk pipelines that take advantage of economies of scale. Pipeline construction costs take into account factors including topography and social impacts. SimCCS can be used to calculate the scale of CCS deployment (local, regional, national). SimCCS’ deployment of a realistic, capacitated pipeline network is a major advancement for planning CCS infrastructure. We demonstrate simCCS using a set of 37 CO₂ sources and 14 reservoirs for California. The results highlight the importance of systematic planning for CCS infrastructure by examining the sensitivity of CCS infrastructure, as optimized by simCCS, to varying CO₂ targets. We finish by identifying critical future research areas for CCS infrastructure.     

‘Capture ready’ regulation of fossil fuel power plants – Betting the UK’s carbon emissions on promises of future technology

Climate change legislation requires emissions reductions, but the market shows interest in investing in new fossil fuelled power plants. The question is whether capture ready policy can reconcile these interests. The term ‘capture ready’ has been used a few years by the UK Government when granting licences for fossil fuelled power plants, but only recently has the meaning of the term been defined. The policy has been promoted as a step towards CCS and as an insurance against carbon lock-in. This paper draws on literature on technology lock-in and on regulation of technology undergoing development. Further, versions of the capture readiness concept proposed to date are compared. Capture readiness requirements beyond the minimum criterion of space on the site for capture operations are explored. This includes integration of capture and power plant, downstream operations, overall system integration and regulation of future retrofitting. Capture readiness comes with serious uncertainties and is no guarantee that new-built fossil plants will be abatable or abated in the future. As a regulatory strategy, it has been over-promised in the UK.     

Carbon capture and storage

Carbon capture and storage (CCS) covers a broad range of technologies that are being developed to allow carbon dioxide (CO₂) emissions from fossil fuel use at large point sources to be transported to safe geological storage, rather than being emitted to the atmosphere. Some key enabling contributions from technology development that could help to facilitate the widespread commercial deployment of CCS are expected to include cost reductions for CO₂ capture technology and improved techniques for monitoring stored CO₂. It is important, however, to realise that CCS will always require additional energy compared to projects without CCS, so will not be used unless project operators see an appropriate value for reducing CO₂ emissions from their operations or legislation is introduced that requires CCS to be used. Possible key advances for CO₂ capture technology over the next 50 years, which are expected to arise from an eventual adoption of CCS as standard practice for all large stationary fossil fuel installations, are also identified. These include continued incremental improvements (e.g. many potential solvent developments) as well as possible step-changes, such as ion transfer membranes for oxygen production for integrated gasifier combined cycle and oxyfuel plants.     

Techno-economic and environmental evaluations of large scale gasification-based CCS project in Romania

Gasification is a promising technology in terms of reducing carbon capture energy and cost penalties as well as for multi-fuel multi-product operation capability. The paper evaluates two carbon capture options in terms of main techno-economic indicators. The first option involves pre-combustion capture, the syngas being catalytically shifted to convert carbon species into CO₂ and H₂. Gas–liquid absorption is used for separate H₂S and CO₂ capture, then clean gas is used for power generation. The second capture option is based on post-combustion capture using chemical absorption. The most promising gasifiers were evaluated in a CCS design.     

Australia: Approaching an energy crossroads

This paper considers energy policy in Australia in the context of its considerable energy resources, climate change and a recent change in government. It examines the possible paths that future energy use and policy in Australia could take, including published projections based largely on a “business as usual” approach and projections based on a dramatic shift towards more efficient use of energy and renewable energy technologies. It also considers the various factors affecting future policy direction, including energy security, the advocacy in Australia for establishing nuclear electricity generation and other parts of the nuclear fuel-cycle, responses to climate change, and carbon sequestration. It concludes that while the Australian Government is currently reluctant to move away from a dependence on coal, and unlikely to adopt nuclear energy generation, a low-emissions future without waiting for the deployment of carbon capture and storage and without resorting to nuclear power is within reach. However, in the face of strong pressure from interest groups associated with energy intensive industry, making the necessary innovations will require further growth of community concern about climate change, and the development of greater understanding of the feasibility of employing low carbon-emissions options.     

Opportunities for low-cost CO2 storage demonstration projects in China

Several CO₂ storage demonstration projects are needed in a variety of geological formations worldwide to prove the viability of CO₂ capture and storage as a major option for climate change mitigation. China has several low-cost CO₂ sources at sites that produce NH₃ from coal via gasification. At these plants, CO₂ generated in excess of the amount needed for other purposes (e.g., urea synthesis) is vented as a relatively pure stream. These CO₂ sources would potentially be economically interesting candidates for storage demonstration projects if there are suitable storage sites nearby.     

European CO2 prices and carbon capture investments

We assess the option to install a carbon capture and storage (CCS) unit in a coal-fired power plant operating in a carbon-constrained environment. We consider two sources of risk, namely the price of emission allowance and the price of the electricity output. First we analyse the performance of the EU market for CO₂ emission allowances. Specifically, we focus on the contracts maturing in the Kyoto Protocol's first commitment period (2008 to 2012) and calibrate the underlying parameters of the allowance price process. Then we refer to the Spanish wholesale electricity market and calibrate the parameters of the electricity price process.We use a two-dimensional binomial lattice to derive the optimal investment rule. In particular, we obtain the trigger allowance prices above which it is optimal to install the capture unit immediately. We further analyse the effect of changes in several variables on these critical prices, among them allowance price volatility and a hypothetical government subsidy.We conclude that, at current permit prices, immediate installation does not seem justified from a financial point of view. This need not be the case, though, if carbon market parameters change dramatically, carbon capture technology undergoes significant improvements, and/or a specific governmental policy to promote these units is adopted.     

The role of carbon capture technologies in greenhouse gas emissions-reduction models: A parametric study for the U.S. power sector

This paper analyzes the potential contribution of carbon capture and storage (CCS) technologies to greenhouse gas emissions reductions in the U.S. electricity sector. Focusing on capture systems for coal-fired power plants until 2030, a sensitivity analysis of key CCS parameters is performed to gain insight into the role that CCS can play in future mitigation scenarios and to explore implications of large-scale CCS deployment. By integrating important parameters for CCS technologies into a carbon-abatement model similar to the EPRI Prism analysis (EPRI, 2007), this study concludes that the start time and rate of technology diffusion are important in determining emissions reductions and fuel consumption for CCS technologies. Comparisons with legislative emissions targets illustrate that CCS alone is very unlikely to meet reduction targets for the electric-power sector, even under aggressive deployment scenarios. A portfolio of supply and demand-side strategies is needed to reach emissions objectives, especially in the near term. Furthermore, model results show that the breakdown of capture technologies does not have a significant influence on potential emissions reductions. However, the level of CCS retrofits at existing plants and the eligibility of CCS for new subcritical plants have large effects on the extent of greenhouse gas emissions reductions.