CO2 Abatement Costs Research Articles

How Not to Reduce Carbon Dioxide Emissions: An Unbalanced Focus on Energy Efficiency in Germany’s Building Rehabilitation Policies

Germany needs to reduce CO2 emissions from space heating in its old buildings to net zero by 2045 to fulfil its climate goals. However, direct CO2 reduction measures in existing buildings receive relatively little subsidy support from the federal government’s German Development Bank, compared to generous subsidies for energy efficiency measures. This interdisciplinary paper evaluates this phenomenon by comparing costs and CO2 abatement effects of ever higher energy efficiency measures, alongside the costs of direct CO2 reduction through heat pumps and onsite photovoltaics. It uses a set of carefully selected reports on the costs and benefits of renovation to a range of energy efficiency standards in three common types of multi-apartment buildings in Germany, updating these for 2024 construction, energy, and finance costs. The cost of the CO2 saved is extremely high with energy efficiency measures and absurdly high with the highest energy efficiency standards, up to 20 times the cost of CO2 abatement through other means, such as offsite renewables. This reduces markedly with onsite CO2 reduction measures. This paper sets this analysis in the context of asking what social, cultural, and discursive factors extol energy efficiency so highly that policy tends to thwart its own stated goal of deeply reducing CO2 emissions.

Thermodynamic and economic analysis of a deployable and scalable process to recover Monomer-Grade styrene from waste polystyrene

Less than 5% of polystyrene is recycled, motivating a search for energy efficient and economical methods for polystyrene recycling that can be deployed at scale. One option is chemical recycling, consisting of thermal depolymerization and purification to produce monomer-grade styrene (>99%) and other co-products. Thermal depolymerization and distillation are readily scalable, well-established technologies; however, to be considered practical, they must be thermodynamically efficient, economically feasible, and environmentally responsible. Accordingly, mass and energy balances of a pyrolysis reactor for thermal depolymerization and two distillation columns to separate styrene from α-methyl styrene, styrene dimer, toluene, and ethyl benzene co-products, were simulated using ASPEN to evaluate thermodynamic and economic feasibility. These simulations indicate that monomer-grade styrene can be recovered with energy inputs <10MJ/kg, comparable to the energy content of pyrolysis co-products. Thermodynamic sensitivity analysis indicates the scope to reduce these values and enhance the robustness of the predictions. A probabilistic economic analysis of multiple scenarios combined with detailed sensitivity analysis indicates that the cost for recycled styrene is approximately twice the historical market value of fossil-derived styrene when styrene costs are fixed at 15% of the total product cost or less than the historical value when feedstock costs are assumed to be zero. A Monte Carlo and Net Present Value-based economic performance analysis indicates that chemical recycling is economically viable for scenarios assuming realistic feedstock costs. Furthermore, the CO2 abatement cost is roughly $1.5 per ton of averted CO2, relative to a pyrolysis process system to produce fuels. As much as 60% of all polystyrene used today could be replaced by chemically recycled styrene, thus quantifying the potential benefits of this readily scalable approach.

Marginal abatement cost of CO2: A convex quantile non-radial directional distance function regression method considering noise and inefficiency

By purchasing emission reduction equipment or reducing production scale, it is possible to effectively decrease CO2. Therefore, understanding the marginal abatement cost (MAC) associated with these methods is crucial for making decisions. However, previous studies using the directional distance function (DDF) approach often mis-specified production functions and neglected data noise. They also assumed decision-making units (DMUs) to be on the production frontier and used proportional changes in inputs and outputs as abatement paths. This paper addresses these limitations by developing the convex quantile non-radial directional distance function (CQR-NDDF) method, which estimates the MAC of CO2 and determines optimal abatement paths for DMUs without assuming a specific production function, employing linear programming techniques. Applying this method to 30 provinces in mainland China from 2011 to 2019, the study finds that China's CO2 MAC increased from 182 to 247 yuan/ton. The lowest-cost abatement path varies by province and time. The club convergence and ordered probit model are employed to conclude that the second industry and urbanization increase the MAC of CO2, while factors such as foreign direct investment, openness level, and human capital decrease the MAC. Moreover, the CQR-NDDF method yields significantly lower MAC estimates than the NDDF method. In conclusion, this paper provides new insights into China's CO2 MAC, emphasizing the importance of considering inefficiency and data noise in MAC estimation. We anticipate that utilizing CO2 MAC as a benchmark for carbon trading market prices could lead to an increase in prices within China's carbon trading market.

CO2 reduction potentials and abatement costs of renewables and flexibility options – A linear optimization approach for the German sector-coupled energy system until 2045

Exploring pathways for transitioning to clean energy to achieve climate change mitigation goals is essential. Addressing the economic impact of decarbonization options requires strategic planning to determine cost-effective CO2 mitigation strategies. The assessment of marginal CO2 abatement cost curves (MACC) is commonly used to link costs and emission reduction of decarbonization measures, with the cumulative CO2 abatement potential and associated costs.This study aims to calculate a step-wise MACC to identify the most cost-effective order of investments in decarbonization measures for the German sector-coupled energy system from 2030 to 2045. It provides in-depth insights into the techno-economic, intertemporal, and intersectoral interactions of decarbonization options by applying a linear optimization model to determine the minimal cost of CO2 abatement.The results show that the optimal strategy for decarbonization includes expanding wind and solar power capacity, and increasing demand-side flexibility, by integrating battery electric vehicles, power-to-heat, and power-to-gas. Results indicate that the interaction between the decarbonization measures is significant and that the integration of surplus electricity through sector-coupling can significantly reduce curtailment. Overall, the presented step-wise MACC approach can support policymakers in determining the most cost-efficient energy strategy by identifying the optimal technology mix to meet specific climate goals.

Entrained flow gasification-based biomass-to-X processes: A techno-economic assessment

In the pursuit of a successful energy transition, synthetic basic chemicals and fuels, alongside renewable energies, play pivotal roles. This study focuses on the utilization of biomass as a carbon source to replace conventional fossil feedstocks, conducting detailed process simulations and techno-economic analyses for various biomass-to-x pathways. Six key products—Methanol, Dimethyl Ether, Methane (SNG), Fischer-Tropsch syncrude, Hydrogen, and Ammonia—derived from entrained flow gasification of a representative biomass are systematically compared. The uniformity of simulation detail and economic methodology enables a direct and comprehensive comparison of these products. Notably, carbon-based products exhibit up to 34% lower average investment costs compared to their hydrogen-based counterparts, namely ammonia and hydrogen. This cost discrepancy is reflected in the levelized costs of manufacturing, with hydrogen-based products emerging as the most energy-expensive. The analysis identifies variable costs as the primary contributor to overall costs with around 50%, followed by fixed investment. The study underscores the critical impact of full load hours, plant lifetime, and feedstock costs on results. This emphasise the importance of detailed planning if alternative feedstock is used to balance fuel costs and enhance plant availability. Among the evaluated products, methanol emerges as the most promising across the evaluated KPIs with costs of 283.48 € MWh−1. However, regarding hydrogen-based products, it is suggested that, especially in the context of CO2 abatement costs, a comprehensive consideration of the long-term system effects is essential to prevent misinvestments during the early stages of the energy transition. This emphasizes the need for strategic planning to ensure a sustainable and economically viable shift towards biomass-derived synthetic fuels.

Cost-effective CO2 abatement in residential heating: A district-level analysis of heat pump deployment

Heat pumps are recognized for their potential to reduce CO2 emissions in residential heating, particularly when replacing traditional natural gas systems. Their performance can be enhanced when integrated into district-level energy management systems and demand response programs. However, the CO2 abatement cost, the expense of reducing emissions through the installation of heat pumps, has not yet been fully explored at the district level. This study reveals a substantial disparity in CO2 abatement costs between typical urban and rural districts, identifying the conditions that make heat pump deployment most cost-effective. Rural districts, with their higher heat demand, emerge as more suitable candidates for the electrification of the heat sector. The research also indicates that district demand-side management not only helps mitigate CO2 abatement costs but also reduces the negative impacts of a large number of heat pumps. Additionally, a lower emission intensity of electricity could lead to a 50% reduction in CO2 abatement costs. This research outlines a cost-effective approach to reducing emissions through the use of heat pumps, thereby setting a benchmark for district-level heat pump investments towards achieving low-carbon districts. The findings could provide valuable information that informs strategic decision-making on the replacement of conventional heating systems with heat pumps.

Role of the energy-carbon-economy nexus and CO2 abatement cost in supporting energy policy analysis: A multi-scenario analysis of the Java-Bali system

Java-Bali is Indonesia's largest power system, with enormous CO2 emissions. Therefore, the Government of Indonesia has committed to reducing CO2 emissions by introducing two policies: (1) a new and renewable energy target and (2) coal phase-out planning. However, no study on the energy-carbon-economic nexus in Indonesia has analyzed the impact of reducing CO2 emissions using these policies. Therefore, this research analyzes the economic impacts on the energy and carbon nexus in the Java-Bali system to obtain and review feasible strategies to support these policies. OSeMOSYS was used in this study to implement multiple scenarios of emission reduction. The results indicate that policies that clearly regulate carbon limits and taxes for power generation companies are required. A carbon limitation of 10,087 million tons with a carbon tax of 67 USD/ton and a carbon limitation of 8482 million tons with a carbon tax of 77 USD/ton are required to supporting the new and renewable energy target and coal phase-out plan. Nuclear energy and liquefied natural gas are crucial for supporting the new and renewable energy targets and coal phase-out policies. Therefore, the government must immediately decide to utilize nuclear energy and guarantee an adequate liquefied natural gas supply at an affordable price. Furthermore, it is crucial to seek alternatives to meet the demand projection through interconnection with other islands that have immense renewable energy sources to meet the new and renewable energy target and successfully implement the coal phase-out plan.

Promoting inter-regional cooperation to reduce CO2 abatement cost in China

CO2 emissions reduction is a global challenge while the associated cost pressure presents a crucial issue. Within a country, each region, with different levels of abatement cost, may play different roles to achieve the national target of CO2 emissions reduction. Such heterogeneity could play a role in the cost efficiency of national CO2 emissions reduction, i.e. the minimum total abatement cost across the entire country. Previous models predominately focus on minimizing the total abatement cost, while the allocation of cooperative benefits is largely overlooked. We constructed a combined regional optimization and game model, i.e., the cooperative emission reduction model. The aim is to achieve the national carbon reduction target while reducing CO2 emissions at a minimum cost through inter-regional cooperation. In order to achieve cooperation, it is imperative to ensure that every participating region can benefit from cooperation. This study developed a cooperative emission reduction model based on the Shapley value method of game theory to determine the mechanism to distribute cooperation benefits amongst participating regions in fairness. Compared to the total costs before applying this model, 17.04 % ~ 33.62 % and 19.59 % ~ 24.62 % total CO2 abatement costs of China can be saved in 2025 and 2030, respectively. This method can be employed in other countries to assist policymakers to establish an appropriate goal for CO2 emission reduction, and formulate a compensation mechanism to promote inter-regional cooperation with fairness and minimum cost.

Marginal CO2 and SO2 Abatement Costs and Determinants of Coal-Fired Power Plants in China: Considering a Two-Stage Production System with Different Emission Reduction Approaches

Marginal abatement cost (MAC) plays an essential role in pricing pollutants and guiding environmental policies. Considering the heavy polluting nature of China’s coal power industry, this paper aims at providing companies and policymakers with more comprehensive information on the cost of abatement by estimating the MACs of CO2 and SO2 for coal-fired power plants (CFPPs) in China. This study contributes to the literature by considering an interconnected two-stage production system to investigate. The estimation framework is advanced in combining the electricity production and pollution abatement process of CFPPs into a convex quantile regression (CQR) model. The results show that the averages of MAC for CO2 and SO2 are estimated to be 367.56 Yuan/ton and 662.30 Yuan/ton, respectively, indicating that the reduction of such emissions is still costly. The heterogeneous analysis then indicates that large CFPPs, central-government-owned power plants (CGOPPs), and low-regulated CFPPs tend to possess lower MACs for CO2. Regarding SO2, large and medium-sized power plants show significantly larger MACs than small plants. In addition, the MACs of SO2 for CGOPPs and high-regulated CFPPs are more concentrated at high levels. In the second part, the Tobit regression analysis was used to discuss the determinants of MACs for CO2 and SO2. Factors like carbon emission intensity, load, and operating hours can notably decrease MACs for CO2, while MACs for SO2 tend to be positively affected by the total abatement cost and the abatement rate of the FGD equipment. In addition, the MACs for the large CFPPs, CGOPPs, and high-regulated CFPPs are more likely to be affected by the selected influence factors. Based on these results, we conclude with some policy recommendations.

Policy pressure to retrofit Germany's residential buildings to higher energy efficiency standards: A cost-effective way to reduce CO2 emissions?

Germany's climate goals require over 75% of its housing stock to be retrofitted for energy efficiency. An important question for Germany and other countries is, what minimum energy efficiency standard should be mandated for housing retrofits so as to reduce CO2 emissions economically efficiently? It has long been known that the marginal costs of energy efficiency increase as standards are pushed higher, and therefore the marginal costs of CO2 abatement increase, but at the same time energy consumption reduces, thereby reducing CO2 emissions. This paper investigates where the social optimum lies between these two effects. In addition to a large database of house sale advertisements containing price and energy efficiency data, it uses two semi-official data sources of modelled and actual energy efficiency upgrades in Germany. It finds that retrofitting to a modestly high standard of about 70 kWh/m2/y entails marginal costs of CO2 abatement comparable to current CO2 prices. However, each step to a higher standard increases these by up to an order of magnitude, with absurdly high marginal costs of CO2 abatement for the highest standards. German policymakers are currently pushing for higher minimum standards, but money could better be spent retrofitting more houses to less stringent standards.

BECCS opportunities in Brazil: Comparison of pre and post-combustion capture in a typical sugarcane mill

In order to make feasible the efforts that would limit the rise of Earth's temperature to no more than 2 °C, profound changes are required in the energy systems. In this sense, BECCS are considered instrumental to attain possible negative emissions. This draws attention to the sugarcane industry in Brazil, where it is possible to produce fuel ethanol at a relative low cost and a large amount of relatively cheap biomass is available. This paper is part of a research that aims to study the combined production of liquid fuels and electricity, using sustainable sources of biomass and maximizing carbon capture. Two cases related to an innovative technology were evaluated and in both the capture is based on amine technology: pre-combustion capture of CO2 from the fuel gas derived from biomass gasification, and post-combustion capture from gas turbine exhaust gases. Information from the scientific literature was used in modelling the systems, as well as estimating energy penalties and costs associated with capturing, transporting and storing CO2. The results indicate technical feasibility of both capture options, but difficulties in setting the full integration of the power unit (BIG-CC) with the sugarcane mill and the CCS system, due to the high demand for thermal energy as low-pressure steam. The estimated CO2 abatement cost is in the range 60–71 €/tCO2 for pre-combustion capture, and 52–63 €/tCO2 in the case of post-combustion. Feasibility results are impacted by the scale of CO2 capture (0.82–1.44 MtCO2/year), particularly in the pre-combustion case, and the relatively high cost of electricity generation.

Case study on decarbonization strategies for LNG export terminals using heat and power from CSP/PV hybrid plants

The race towards decarbonization is driving major oil and gas companies to explore means to use renewable heat and power for their plants as part of their commitment to reduce their carbon intensity by 80% to 100% by 2050 (Holbrook, 2023). In terms of GHG (Greenhouse Gas) emissions, natural gas is considered the cleanest fossil fuel option available, and decarbonization of new LNG (Liquefied Natural Gas) projects is on the radar of many LNG projects developers. In addition, LNG cargos will have to be certified in the future by accredited authorities to meet defined GHG emission levels (Stern, 2019).This research study investigates a new concept of providing both heat and power from a PV (Photovoltaic) and CSP (Concentrated Solar Power) hybrid plant to meet the energy demand of an LNG export terminal. Two locations have been investigated for potential future LNG projects: Karratha in Australia and Ras Laffan in Qatar. Both locations have DNI values higher than 2000 kWh/m2/year, which is the minimum level required for CSP technology (Lovegrove and Stein, 2021).The LCCA (Levelized Cost of CO2 abatement) was used to compare the various solar configurations to select the option that will bring the greatest amount of CO2 reduction for the same investment cost (CGEP, 2020). The solar configurations technical parameters were defined based on the surface land available, natural gas feed composition and LNG plant design characteristics. The techno-economic assessment was carried-out taking into consideration the electricity price, the grid carbon intensity, and the CO2 tax in the region.Whilst in Australia a collocated single plant is favourable in terms of land availability and DNI (Direct Normal Irradiation) level, in Qatar, heat and power production have been separated into two distinct locations. Next to the LNG plant, a CSP plant provides heat only, whereas 130 km away, the hybrid PV/CSP plant located at Qurain EL Bawl provides electric power.The results indicate that the PV/CSP hybrid plant significantly accelerates the decarbonization of energy supply to the “All electric” LNG Plant. Depending on the solar field size, the quantity of CO2 emitted between 2025 and 2050 is reduced by 78–81% for Karratha (Australia) and by 82–88% for Ras Laffan (Qatar) compared to a grid connected plant.In addition, the economic assessment indicated that buying electricity from the grid during the period 2025–2050 would be more expensive for Australia then investing in a PV/CSP plant. In Qatar, the LCOE range of 93–110 US$/MWh is not competitive with the price of electricity in the region Qatar, mainly because of energy subsidies, however both the carbon tax and electricity price will need to be raised to the same level as in Australia to diversify and expand the power sector in the region.

Implementing a highly adaptable method for the multi-objective optimisation of energy systems

In order to mitigate climate change, the energy sector undergoes a transformation towards a climate-neutral future based on renewable energy sources. Energy system models generate insights and support decision making for this transformation. In the face of, e.g., growingly complex and important environmental assessments and stakeholder structures, considering multiple objectives in these models becomes essential to realistically reflect existing interests. However, there is a lack of highly adaptable energy system models incorporating multiple objectives. We present an implementation of the augmented epsilon-constraint method with the highly adaptable energy system optimisation framework Backbone. It enables the simultaneous optimisation of multiple objectives, such as the minimisation of costs, CO2 emissions or self-sufficiency for a broad range of energy systems including different sectors and scales. For this purpose, new objective functions and constraints are implemented in Backbone. They are used by an external algorithm in a sequence of parallelised optimisations to cope with the complexity of real-world applications. The method is adaptable to further objectives and scalable to large and complex systems. Applications to the Western and Southern European power sector in 2050 and a sector-coupled mixed-integer household-level model demonstrate its benefits and adaptability. Pareto fronts, technology use and trade-offs are analysed and quantified. In the European power sector, emission reductions of up to 90% can be achieved at marginal CO2 abatement costs of below 100 EUR/(tCO2). For the household, energy imports from the public grids can be reduced by 70% at 20% higher cost and average cost of self-sufficiency of 2.6ct/kWh. We expect that the presented methods and models reveal new valuable insights to modellers and decision makers.

How has China's low-carbon city pilot policy influenced its CO2 abatement costs? Analysis from the perspective of the shadow price

Extant studies mainly focus on the emissions reduction effect of environmental regulations, ignoring their influences on the costs of reducing emissions. This study takes the low-carbon city (LCC) pilot project in China as a quasi-natural experiment and examines its impact on the marginal abatement cost (MAC) of CO2 emissions. Based on city-level data from 2003 to 2018, it first utilizes a dual model of non-linear programming to estimate the shadow price of CO2 emissions, which is applied to measure the MAC. Then, it employs the difference-in-differences (DID) approach to estimate the causal impact. The results suggest that the LCC project has increased the MAC of CO2 emissions of pilot cities by 5.27% through two opposite effects: (i) The green technology progress effect, which decreases the MAC; (ii) The emissions intensity effect, which increases the MAC. The results are robust after accounting for heterogeneous treatment effects, omitted variables, sample selection bias, potential outliers, and confounding factors. Besides, the heterogeneity analysis suggests that the LCC project has a greater impact on small and medium-sized cities and non-resource-based cities. The findings of this study provide a more thorough knowledge of the policy effects of the LCC project and demonstrate the importance of green technology progress in reducing CO2 emissions.

Energy mix for net zero CO2 emissions by 2050 in Japan

AbstractThis study investigated cost‐effective energy strategies for realizing net zero CO2 emissions in Japan by 2050, employing an energy system optimization model with hourly electricity balances. The detailed temporal resolution enables the model to capture the intermittency of variable renewable energy (VRE) and the costs of system integration measures. Siting constraints on VRE, such as prohibiting solar PV and onshore wind developments in forests and offshore wind developments inside fishery rights areas, are incorporated in the model to reflect the environmental protection and social acceptance perspectives. Simulation results imply that a well‐balanced power generation mix, combining renewables, nuclear, gas‐fired with carbon capture and storage, as well as ammonia‐fired, would contribute to curbing mitigation costs. In contrast, a simulation case with very high VRE penetration poses economic challenges. The average shadow price of electricity in 2050 in a 100% renewables case (RE100) is projected to be more than doubled from a reference case which is based on middle‐of‐the‐road assumptions. Marginal CO2 abatement cost in 2050 increases from 49,200 JPY/tCO2 in the reference case to 75,300 JPY/tCO2 in the RE100 case. The economic viability of high VRE penetration is improved by relaxing the siting constraints, although it may raise environmental and social concerns.

Decarbonization scenarios of the U.S. Electricity system and their costs

Decarbonizing the electricity system to zero-carbon emission is crucial for climate change mitigation. Previous studies have shown that such a transition in the United States (U.S.) may lead to higher system cost compared to a business-as-usual case, but it is not well-known how the cost of electricity generation varies at sub-regional level under the transition, and studies have rarely evaluated the trade-off between the cost and avoided climate damages, as well as the potential roles of negative emission technologies (NETs) in the electricity decarbonization. Here, we present a regionally resolved national model to quantify the cost of decarbonizing the U.S. electricity system under a set of possible scenarios. The results show that, compared to the reference scenario without a decarbonization policy, reaching zero CO2 emission by 2050 would incur, depending on the scenarios, 335–494 billion USD additional cost to the U.S. electric power sector during 2020–2050. The regional costs of electricity generation ranges from 2.4 to 4.7 cent/kWh, largely due to the generation profiles and renewable resources availability of those regions. The additional costs can be translated to an average CO2 abatement cost of 29–59 USD/metric ton CO2 (with 2%–7% discount rates), which are comparable to the social cost of carbon in the literature at around 4% discount rate. The results also show that the cost of mitigating the last few percent CO2 emission from the U.S. electricity system may exceed the costs of NETs, indicating an opportunity for NETs to contribute to electricity decarbonization.

CO2 abatement costs in China and BRI countries: From the perspective of technological heterogeneity

As China cannot achieve its emission reduction target without cooperating with other countries, the international carbon trading market has become a part of China’s carbon trading market system. The Belt and Road Initiative (BRI) has brought many development opportunities to countries participating, but critics have also voiced concerns about the environmental and climate degradation it might bring. Thus China is making a great effort towards building a green and low-carbon BRI, part of which is a joint effort with other countries to cut greenhouse gas emission and achieve the 2,030 sustainable development goals. The estimation of abatement costs is the basis of regional carbon emission reduction cooperation and a prerequisite for establishing a regional carbon trading market. Taking into account the technological heterogeneity, this paper uses linear programming to estimate inefficiency level for China and BRI countries, and further calculates the marginal abatement cost (MAC) of carbon dioxide for each country. The results show that after considering technological heterogeneity, the average inefficiency level for China and BRI countries is 2.410%, which is about 26.526% lower than the traditional geographic grouping approach, indicating that the technological heterogeneity among BRI countries is significant and cannot be ignored. Most countries have a low inefficiency level, some countries show a clear trend. China has an average marginal abatement cost of 1440.183 USD/ton. As the marginal abatement cost varies greatly among countries, a large amount of abatement cost could be saved for China and BRI countries if the cost difference is exploited.

Emission Trading System, Carbon Market Efficiency, and Corporate Innovations.

Taking China’s emission trading system (ETS) pilot in 2013 as a quasi-natural experiment, this paper uses the difference-in-differences (DID) models to study whether the regional pilot ETS can promote technological innovation in enterprises. In addition, this paper examines the influence mechanism of the ETS innovation effect, with a focus on three key dimensions of the carbon market efficiency: market price effectiveness, market product diversity, and market order normativity. The results show that the pilot ETS has significantly promoted the technological innovation of regulated enterprises, specifically, 1.405*** for the total R&D investment, and 2.783*** for the number of patent applications. Moreover, the regional carbon price has a positive moderating effect on the innovation effect of ETS. Meanwhile, the innovation effect is more significant when the gap between the carbon price and the marginal abatement cost (MAC) of CO2 is smaller, when the carbon financial derivatives are more abundant, or when the local market supervision is stronger. This study provides empirical evidence for the improvement of the national unified market and provides useful policy implications for developing countries to design ETS suitable for their national conditions.

Model-based step-wise marginal CO2 abatement cost curves to determine least-cost decarbonization pathways for sector-coupled energy systems

Energy system modeling is highly relevant to support policymakers in defining strategies to achieve the European Green Deal targets towards carbon neutrality in 2050. Therefore, marginal CO2 abatement cost curves are widely used in climate policy to assess the relationship between total cost changes and CO2 emission reductions. Various methods exist for deriving abatement cost curves, leading to different results and policy implications. Most model-based methods derive smooth curves that can be transformed into step-wise curves through decomposition analysis, lacking system interactions at high temporal, sectoral, and techno-economic resolution. This paper overcomes these limitations by presenting a linear optimization approach with an hourly resolution to derive step-wise marginal CO2 abatement cost curves for the German sector-coupled power system in 2030. Next to methodological insights, results indicate that early adoption of vehicle-to-grid ensures faster photovoltaic rooftop integration by reducing CO2 abatement costs. Further, vehicle-to-grid replaces storage systems and decreases electricity generation costs while having no impact on CO2 abatement costs of ground-mounted photovoltaic and onshore wind. Additionally, results show a high level of techno-economical detail and the least-cost sequential order of an optimal technology portfolio, allowing policymakers to formulate appropriate measures to achieve decarbonization targets.

Multi-objective optimization of CO2 recycling operations for CCUS in pre-salt carbonate reservoirs

This study evaluates the potential of recycling carbon dioxide (CO2) in the associated gas in ultra-deepwater pre-salt carbonate reservoirs for Carbon Capture Utilization and Storage (CCUS). We performed compositional subsurface modeling of a hypothetical field for multi-objective optimization, aiming at minimizing carbon emissions whilst maximizing the project's Net Present Value (NPV). Although no absolute reduction in total CO2 emissions was met with economic improvement, all simulated CCUS scenarios yielded a lower carbon footprint oil, with 43.5% reduction in operational emissions and up to 25.5% increase in NPV. The best CCUS case, a tapered Water Alternating Gas (WAG) design, presented break-even oil price of 39.5 USD/STB and operational CO2 abatement cost of negative 94.8 USD/tCO2 abated, also showing significant reduction in number of squeeze treatments and cost of calcite scale management.