Interactions and implications of renewable and climate change policy on UK energy scenarios

As a response to the twin challenges of climate change mitigation and energy security, the UK government has set a groundbreaking target of reducing the UK’s economy-wide carbon emissions by 80% from 1990 levels by 2050. A second key UK energy policy is to increase the share of final energy consumption from renewables sources to 15% by 2020, as part of the wider EU Renewable Directive. The UK’s principle mechanisms to meet this renewable target are the Renewable Obligation (RO) in the electricity sector, the Renewable Transport Fuel Obligation (RTFO), and most recently the Renewable Heat Programme (RHP) for buildings. This study quantifies a range of policies, energy pathways, and sectoral trade-offs when combining mid- and long-term UK renewables and CO₂ reduction policies. Stringent renewable policies are the binding constraints through 2020. Furthermore, the interactions between RO, RTFO, and RHP policies drive trade-offs between low carbon electricity, bio-fuels, high efficiency natural gas, and demand reductions as well as resulting 2020 welfare costs. In the longer term, CO₂ reduction constraints drive the costs and characteristics of the UK energy system through 2050.     

The role of energy-service demand reduction in global climate change mitigation: Combining energy modelling and decomposition analysis

In order to reduce energy-related CO₂ emissions different options have been considered: energy efficiency improvements, structural changes to low carbon or zero carbon fuel/technologies, carbon sequestration, and reduction in energy-service demands (useful energy). While efficiency and technology options have been extensively studied within the context of climate change mitigation, this paper addresses the possible role of price-related energy-service demand reduction. For this analysis, the elastic demand version of the TIAM–UCL global energy system model is used in combination with decomposition analysis. The results of the CO₂ emission decomposition indicate that a reduction in energy-service demand can play a limited role, contributing around 5% to global emission reduction in the 21st century. A look at the sectoral level reveals that the demand reduction can play a greater role in selected sectors like transport contributing around 16% at a global level. The societal welfare loss is found to be high when the price elasticity of demand is low.     

Overview of thermal energy storage (TES) potential energy savings and climate change mitigation in Spain and Europe

Thermal energy storage (TES) is nowadays presented as one of the most feasible solutions in achieving energy savings and environmentally correct behaviors. Its potential applications have led to R&D activities and to the development of various technology types. However, so far there is no available data on a national scale in Spain and on a continental level in Europe, to corroborate the associated energetic and environmental benefits derived from TES. This is why, based on a previous potential calculation initiative model performed in Germany, this work intends to provide a first overview of the Spanish TES potential as well as an European overview. Load reductions, energy savings, and CO₂ emissions reductions are tackled for the buildings and industrial sector. Results depend on the amount of implementation and show that, in the case of Europe for instance, yearly CO₂ emissions may get to be cut down up to around 6% in reference to 1990 emission levels.     

Technological change and the timing of mitigation measures

We use a coupled carbon-cycle and energy systems engineering model to analyze the future time path of carbon emissions under an illustrative CO₂ concentration stabilization limit of 550 ppm. Our findings confirm the emission pattern as found by WRE: global emissions rise initially, pass through stabilization, in order to decline in the second half of the 21st century. We show that for a given CO₂ concentration target, emission trajectories within an intertemporal optimization framework depend mainly on two factors: the discount rate, and the representation of technological change as either static or dynamic. We obtain a similar near-term emission time path as WRE when using a model with static technology and a discount rate of 7%. We obtain a trajectory with lower emissions in the near-term when using a lower discount rate and/or treating technology dynamics endogenously in the model. We briefly outline a model that endogenizes technological change through learning curves. We then compare differences in emission trajectories between alternative model formulations of technological change. They are sufficiently small as to be of secondary importance when compared to treating CO₂ concentration stabilization as an inter-temporal optimization problem or not. Whereas our results confirm the computational results of WRE, we arrive nonetheless at different policy conclusions. If long-term emission reduction is the goal, we cannot follow ‘business as usual' even in the short-term. Action needs to start now. Action does not necessarily mean aggressive short-term emission reductions but rather enhanced R&D and technology demonstration efforts that stimulate technological learning. These are the necessary preconditions that long-term reduction targets can be met with improved technology and at costs lower than today. We close by pointing out two further critical issues: uncertainty, and the possible mismatch between the world of economic models and that of climate policy.     

Decomposition analysis of CO2 emission in long-term climate stabilization scenarios

To achieve the stabilization of greenhouse gas (GHG) concentrations in the atmosphere, the international community will need to intensify its long-term efforts. Many EU countries have released national long-term scenarios toward 2050, and their ambitious targets for CO₂ emission reduction are aiming at a decrease of more than 50% of today's emission. In April 2004, Japan began a research project on its long-term climate policy. This paper discusses the long-term scenarios in other countries and the medium-term scenarios in Japan to support the development of a Japan's long-term climate stabilization scenario. In this study, CO₂ emission is decomposed with an extended Kaya identity (indexes: CO₂ capture and storage, carbon intensity, energy efficiency, energy intensity, economic activity) and a Reduction Balance Table is developed.     

CO2 emissions and mitigation potential in China’s ammonia industry

Significant pressure from increasing CO₂ emissions and energy consumption in China’s industrialization process has highlighted a need to understand and mitigate the sources of these emissions. Ammonia production, as one of the most important fundamental industries in China, represents those heavy industries that contribute largely to this sharp increasing trend. In the country with the largest population in the world, ammonia output has undergone fast growth spurred by increasing demand for fertilizer of food production since 1950s. However, various types of technologies implemented in the industry make ammonia plants in China operate with huge differences in both energy consumption and CO₂ emissions. With consideration of these unique features, this paper attempts to estimate the amount of CO₂ emission from China’s ammonia production, and analyze the potential for carbon mitigation in the industry. Based on the estimation, related policy implications and measures required to realize the potential for mitigation are also discussed.     

CCS: A future CO2 mitigation option for Germany?—A bottom-up approach

The role that carbon capture and storage (CCS) technologies could play within the framework of an overall CO₂ mitigation strategy is examined in the form of scenarios up to 2030 with the example of Germany. As the calculations show, the use of CCS can represent an interesting mitigation option in view of stringent CO₂ reduction goals. The scenarios, performed with the aid of the IKARUS optimization model, however, also show that according to cost-efficiency criteria a large number of measures would have to be taken covering all energy sectors. CCS can at best represent one element in an overall strategy. The model results show that a mitigation goal for 2030 corresponding to a 35% reduction of CO₂ as compared to 1990 is necessary to trigger a significant contribution of CCS. As an alternative to a CO₂ restriction, we also calculated reduction scenarios based on CO₂ penalties. These scenarios showed that a penalty price of approximately 30 €/tCO₂ is necessary before CCS can be included in the model.     

Heating and cooling energy demand and related emissions of the German residential building stock under climate change

The housing sector is a major consumer of energy. Studies on the future energy demand under climate change which also take into account future changes of the building stock, renovation measures and heating systems are still lacking. We provide the first analysis of the combined effect of these four influencing factors on the future energy demand for room conditioning of residential buildings and resulting greenhouse gas (GHG) emissions in Germany until 2060. We show that the heating energy demand will decrease substantially in the future. This shift will mainly depend on the number of renovated buildings and climate change scenarios and only slightly on demographic changes. The future cooling energy demand will remain low in the future unless the amount of air conditioners strongly increases. As a strong change in the German energy mix is not expected, the future GHG emissions caused by heating will mainly depend on the energy demand for future heating.     

Towards a low-carbon future in China's building sector—A review of energy and climate models forecast

This article investigates the potentials of energy saving and greenhouse gases emission mitigation offered by implementation of building energy efficiency policies in China. An overview of existing literature regarding long-term energy-demand and carbon dioxide (CO₂) emission forecast scenarios is presented. Energy consumption in buildings could be reduced by 100–300 million tons of oil equivalent (mtoe) in 2030 compared with the business-as-usual (BAU) scenario, which means that 600–700 million metric tons of CO₂ emissions could be saved by implementing appropriate energy policies within an adapted institutional framework. The main energy-saving potentials in buildings can be achieved by improving a building's thermal performance and district heating system efficiency. The analyses also reveal that the energy interchange systems are effective especially in the early stage of penetration. Our analysis on the reviewed models suggests that more ambitious efficiency improvement policies in both supply- and demand-side as well as the carbon price should be taken into account in the policy scenarios to address drastic reduction of CO₂ emission in the building sector to ensure climate security over the next decades.     

Development of a scalable infrastructure model for planning electricity generation and CO2 mitigation strategies under mandated reduction of GHG emission

In a power-generation system, power plants as major CO₂ sources may be widely separated, so they must be connected into a comprehensive network to manage both electricity and CO₂ simultaneously and efficiently. In this study, a scalable infrastructure model is developed for planning electricity generation and CO₂ mitigation (EGCM) strategies under the mandated reduction of GHG emission. The EGCM infrastructure model is applied to case studies of Korean energy and CO₂ scenarios in 2020; these cases consider combinations of prices of carbon credit and total electricity demand fulfilled by combustion power plants. The results highlight the importance of systematic planning for a scalable infrastructure by examining the sensitivity of the EGCM infrastructure. The results will be useful both to help decision makers establish a power-generation plan, and to identify appropriate strategies to respond to climate change.     

The empirical effects of a gasoline tax on CO2 emissions reductions from transportation sector in Korea

The introduction of carbon tax is expected to mitigate GHG emissions cost-effectively. With this expectation identifying the impacts of carbon tax on energy demand and GHG emission reductions is an interesting issue. One of the basic methods of estimating these impacts is using the price elasticity.     

Decomposition analysis and mitigation strategies of CO2 emissions from energy consumption in South Korea

Energy-related CO₂ emissions in South Korea have increased substantially, outpacing those of Organisation for Economic Co-operation and Development (OECD) countries since 1990. To mitigate CO₂ emissions in South Korea, we need to understand the main contributing factors to rising CO₂ levels as part of the effort toward developing targeted policies. This paper aims to analyze the specific trends and influencing factors that have caused changes in emissions patterns in South Korea over a 15-year period. To this end, we employed the Log Mean Divisia index method with five energy consumption sectors and seven sub-sectors in terms of fuel mix (FM), energy intensity (EI), structural change (SC) and economic growth (EG). The results showed that EG was a dominant explanation for the increase in CO₂ emissions in all of the sectors. The results also demonstrated that FM causes CO₂ reduction across the array of sectors with the exception of the energy supply sector. CO₂ reduction as a function of SC was also observed in manufacturing, services and residential sectors. Furthermore, EI was an important driver of CO₂ reduction in most sectors except for several manufacturing sub-sectors. Based on these findings, it appears that South Korea should implement climate change policies that consider the specific influential factors associated with increasing CO₂ emissions in each sector.     

Heat optimisation of a staged gas–solid mineral carbonation process for long-term CO2 storage

Carbonation of magnesium silicates offers an interesting option for CO₂ emission mitigation in Finland, a country with large resources of serpentine-type minerals. Wet processes using aqueous solutions show reasonable chemical kinetics combined with poor energy economy. A dry, gas–solid process with slower chemical kinetics (demonstrated previously), but better energy economy could be an alternative. This paper addresses the energy economy of a two- or three-stage gas–solid process for magnesium silicate carbonation. It involves production of reactive magnesium as magnesium oxide or hydroxide in an atmospheric pressure step, followed by carbonation at elevated pressures that allow for reasonable carbonation reaction kinetics under conditions where magnesium carbonate is thermodynamically stable. For a feasible large-scale process the kinetics in the individual reactors must be fast enough, while the heat produced in the carbonation step must be sufficient to compensate for energy inputs to the preceding step(s). Results give reactor temperature combinations that allow for operation at a negative or zero energy input, for given carbonation reactor pressure and degree of carbonation conversion, and other process energy requirements. Softwares used were HSC and Aspen Plus. Also, some results from gas–solid kinetics studies with magnesium oxide-based materials at the pressures considered are included.     

Application of a detailed dimensional solid oxide fuel cell model in integrated gasification fuel cell system design and analysis

Integrated gasification fuel cell (IGFC) systems that combine coal gasification and solid oxide fuel cells (SOFC) are promising for highly efficient and environmentally sensitive utilization of coal for power production. Most IGFC system analysis efforts performed to-date have employed non-dimensional SOFC models, which predict SOFC performance based upon global mass and energy balances that do not resolve important intrinsic constraints of SOFC operation, such as the limits of internal temperatures and species concentrations. In this work, a detailed dimensional planar SOFC model is applied in IGFC system analysis to investigate these constraints and their implications and effects on the system performance. The analysis results further confirm the need for employing a dimensional SOFC model in IGFC system design. To maintain the SOFC internal temperature within a safe operating range, the required cooling air flow rate is much larger than that predicted by the non-dimensional SOFC model, which results in a larger air compressor design and operating power that significantly reduces the system efficiency. Options to mitigate the challenges introduced by considering the intrinsic constraints of SOFC operation in the analyses and improve IGFC design and operation have also been investigated. Novel design concepts that include staged SOFC stacks and cascading air flow can achieve a system efficiency that is close to that of the baseline analyses, which did not consider the intrinsic SOFC limitations.     

Long-term CO2 emissions reduction target and scenarios of power sector in Taiwan

This study analyses a series of carbon dioxide (CO₂) emissions abatement scenarios of the power sector in Taiwan according to the Sustainable Energy Policy Guidelines, which was released by Executive Yuan in June 2008. The MARKAL-MACRO energy model was adopted to evaluate economic impacts and optimal energy deployment for CO₂ emissions reduction scenarios. This study includes analyses of life extension of nuclear power plant, the construction of new nuclear power units, commercialized timing of fossil fuel power plants with CO₂ capture and storage (CCS) technology and two alternative flexible trajectories of CO₂ emissions constraints. The CO₂ emissions reduction target in reference reduction scenario is back to 70% of 2000 levels in 2050. The two alternative flexible scenarios, Rt4 and Rt5, are back to 70% of 2005 and 80% of 2005 levels in 2050. The results show that nuclear power plants and CCS technology will further lower the marginal cost of CO₂ emissions reduction. Gross domestic product (GDP) loss rate in reference reduction scenario is 16.9% in 2050, but 8.9% and 6.4% in Rt4 and Rt5, respectively. This study shows the economic impacts in achieving Taiwan's CO₂ emissions mitigation targets and reveals feasible CO₂ emissions reduction strategies for the power sector.     

CO<Subscript>2</Subscript> mitigation in coal gasification cogeneration systems with integration of the shift reaction,CO<Subscript>2</Subscript> absorption and methanol production

Cogeneration of electricity and liquid fuel can achieve higher efficiencies than electricity generation alone in Integrated Gasification Combined Cycle (IGCC), and cogeneration systems are also expected to mitigate CO₂ emissions. A proposed methanol-electricity cogeneration system was analyzed in this paper using exergy method to evaluate the specified system. A simple cogeneration scheme and a complicated scheme including the shift reaction and CO₂ removal were compared. The results show that the complicated scheme consumes more energy, but has a higher methanol synthesis ratio with partial capture of CO₂. In those methanol and electricity cogeneration systems, the CO₂ mitigation is not merely an additional process that consumes energy and reduces the overall efficiency, but is integrated into the methanol production.     

Interactions between measures for the support of electricity from renewable energy sources and CO2 mitigation

As Europe wants to move towards a secure, sustainable and competitive energy market, it has taken action, amongst other, to support electricity from renewable energy sources (RES-E) and to mitigate CO₂ emissions. This paper first qualitatively discusses price- and quantity-based measures for RES-E deployment as well as CO₂ mitigation. Next, a simulation model is developed to quantitatively discuss the effects of a tradable green certificate system, a premium mechanism, a tradable CO₂ allowance system and a CO₂ tax on both RES-E deployment and CO₂ mitigation. A three-regional model implementation representing the Benelux, France and Germany is used. In a first step of simulations, all measures are implemented separately. In a second step, combinations of both RES-E supporting and CO₂ mitigating measures are simulated and discussed. Significant indirect effects are demonstrated, especially for RES-E supporting measures on the reduction of CO₂ emissions. Interactions between different measures show that the price level of quantity-based measures can be strongly influenced.     

Impacts of wind power generation and CO2 emission constraints on the future choice of fuels and technologies in the power sector of Vietnam

This paper examines the impacts of wind power generation on the future choice of fuels and technologies in the power sector of Vietnam. The study covers a time frame of 20 yr from 2005 to 2025 and the MARKAL model has been chosen to be adaptable to this specific task. The results of the study show that on a simple cost base, power generated from wind is not yet competitive with that of fossil fuel-based power plants. In order to make wind energy competitive, either carbon tax or an emission reduction target on the system must be imposed. The presence of wind power would affect not only the change in generation mix from coal-based power plants to wind turbines but also an increase in the capacity of other technologies which emit less carbon dioxide. It thus helps reduce fossil fuel requirement and consequently enhances energy security for the country. The study also shows that wind turbine in Vietnam could be a potential CDM project for annex I party countries.     

A long-term view of fossil-fuelled power generation in Europe

The paper presents a view into the long term future of fossil-fuelled power generation in the European Union, based on a number of alternative scenarios for the development of the coal, natural gas and CO₂ markets, and the penetration of renewable and nuclear technologies. The new fossil fuelled capacity needed and the likely technology mix are estimated using a cost optimisation model based on the screening curve method, taking into consideration the rate of retirement of the current power plant fleet, the capacity already planned or under construction and the role of carbon capture and storage technologies. This analysis shows that measures to increase both non-fossil-fuel-based power generation and the price of CO₂ are necessary to drive the composition of the European power generation capacity so that the European policy goal of reducing greenhouse gas emissions is achieved. Meeting this goal will however require a high capital investment for the creation of an optimal fossil fuel power plant technology mix.     

A review on emissions and mitigation strategies for road transport in Malaysia

The emissions from road transport are serious threats to urban air quality and global warming. The first step to develop effective policies is to determine the source and amount of emissions produced. This paper attempts to review emissions from road transport using COPERT 4 model and examined possible emission mitigation strategies. In road transport, results have show that passenger cars are the main cause of CO₂, N₂O and CO emissions, while motorcycles are main source of hydrocarbon (HC) emissions. However, light duty vehicles and heavy duty vehicles are the main contribution of particulate matters. The total CO₂ equivalent emissions for road transport in Malaysia are 59,383.51 ktonnes for year 2007. Further results show that CO₂ emission is the primary source of greenhouse gas pollution which is 71% of the total CO₂ equivalent. A parametric study was conducted to estimate the potential emission mitigation strategies for road transport by taking the emissions in 2007 as a reference year. It was observed that promoting the public transport is an effective strategy to reduce emissions and fuel consumption from the technical view point. It can totally save up to 1044 ktonnes of fuel consumption and total CO₂ equivalents emissions can be decreased by 7%. It was noted that, fleet renewal and promoting natural gas vehicles will significantly contribute in the reduction of emissions in Malaysia.