Five-year technology selection optimization to achieve specific CO2 emission reduction targets

Long-term planning for replacement of fossil fuel energy technologies with renewables is of great importance for achieving GHG emission reduction targets. The current study is focused on developing a five-year mathematical model for finding the optimal sizing of renewable energy technologies for achieving certain CO₂ emission reduction targets. A manufacturing industrial facility which uses CHP for electricity generation and natural gas for heating is considered as the base case in this work. Different renewable energy technologies are developed each year to achieve a 4.53% annual CO₂ emission reduction target. The results of this study show that wind power is the most cost-effective technology for reducing emissions in the first and second year with a cost of 44 and 69 CAD per tonne of CO₂, respectively. Hydrogen, on the other hand, is more cost-effective than wind power in reducing CO₂ emissions from the third year on. The cost of CO₂ emission reduction with hydrogen doesn't change drastically from the first year to the fifth year (107 and 130 CAD per tonne of CO₂). Solar power is a more expensive technology than wind power for reducing CO₂ emissions in all years due to lower capacity factor (in Ontario), more intermittency (requiring mores storage capacity), and higher investment cost. A hybrid wind/battery/hydrogen energy system has the lowest emission reduction cost over five years. The emission reduction cost of such hybrid system increases from 44 CAD per tonne of CO₂ in the first year to 156 CAD per tonne of CO₂ in the fifth year. The developed model can be used for long-term planning of energy systems for achieving GHG emission targets in a regions/country which has fossil fuel-based electricity and heat generation infrastructure.     

Exploring the potential of wind energy for a coastal state

Adequate recognition of the wind energy potential of coastal states may have far-reaching effects on the development of the energy systems of these countries. This study evaluates wind energy resources in Taiwan with the aid of a geographic information system (GIS), which allows local potentials and restrictions such as climate conditions, land uses, and ecological environments to be considered. The findings unveiled in this study suggest a significant role for offshore wind energy resources, which may constitute between 94% and 98% of overall wind resources in Taiwan. Total power yield from wind energy could reach between 150 and 165 TWh, which would have, respectively, accounted for between 62% and 68% of Taiwan's total power generation of 243 TWh in 2007. Based on the Taiwan's current emission factor of electricity, wind energy has the potential to reduce CO₂ emissions by between 94 and 102 million ton per year in Taiwan, which is, respectively, equivalent to 28% and 31% of the national net equivalent CO₂ emissions released in 2002. However, the challenge of managing the variability of wind power has to be addressed before the considerable contribution of wind energy to domestic energy supply and CO₂ reduction can be realized.     

Carbon intensity of electricity in ASEAN: Drivers,performance and outlook

The Association of Southeast Asian Nations (ASEAN), with its ten member countries, has a total population exceeding 600 million. Its energy-related CO₂ emissions have been growing and in 2013 amounted to 3.6% of total global emissions. About 40% of ASEAN's energy-related CO₂ emissions are currently attributable to electricity production. In view of this high share, we study the CO₂ emissions of ASEAN's electricity production sector with a focus on the aggregate emission intensity (ACI) given by the level of CO₂ emissions for each unit of electricity produced. Drivers of ACI are analysed for individual countries and spatial analysis is conducted by comparing factors contributing to differences between the ACIs of individual countries and that of the ASEAN average. Arising from these analyses and in light of the current developments, it is concluded that drastic actions need to be taken both at the national and regional levels in order to reduce growth in the region's electricity-related CO₂ emissions. Two key policy issues, namely overcoming national circumstances to improve electricity generation mix and improving power generation efficiency, are further discussed.     

Electricity consumption and CO2 capture potential in Spain

In this paper, different electricity demand scenarios for Spain are presented. Population, income per capita, energy intensity and the contribution of electricity to the total energy demand have been taken into account in the calculations. Technological role of different generation technologies, i.e. coal, nuclear, renewable, combined cycle (CC), combined heat and power (CHP) and carbon capture and storage (CCS), are examined in the form of scenarios up to 2050. Nine future scenarios corresponding to three electrical demands and three options for new capacity: minimum cost of electricity, minimum CO₂ emissions and a criterion with a compromise between CO₂ and cost (CO₂-cost criterion) have been proposed. Calculations show reduction in CO₂ emissions from 2020 to 2030, reaching a maximum CO₂ emission reduction of 90% in 2050 in an efficiency scenario with CCS and renewables. The contribution of CCS from 2030 is important with percentage values of electricity production around 22–28% in 2050. The cost of electricity (COE) increases up to 25% in 2030, and then this value remains approximately constant or decreases slightly.     

Optimizing hybrid offshore wind farms for cost-competitive hydrogen production in Germany

Nearly 96% of the world's current hydrogen production comes from fossil-fuel-based sources, contributing to global greenhouse gas emissions. Hydrogen is often discussed as a critical lever in decarbonizing future power systems. Producing hydrogen using unsold offshore wind electricity may offer a low-carbon production pathway and emerging business model. This study investigates whether participating in an ancillary service market is cost competitive for offshore wind-based hydrogen production. It also determines the optimal size of a hydrogen electrolyser relative to an offshore wind farm. Two flexibility strategies for offshore wind farms are developed in this study: an optimal bidding strategy into ancillary service markets for offshore wind farms that build hydrogen production facilities and optimal sizing of Power-to-Hydrogen (PtH) facilities at wind farms. Using empirical European power market and wind generation data, the study finds that offshore-wind based hydrogen must participate in ancillary service markets to generate net positive revenues at current levels of wind generation to become cost competitive in Germany. The estimated carbon abatement cost of “green” hydrogen ranges between 187 EUR/tonCO₂e and 265 EUR/tonCO₂e. Allowing hydrogen producers to receive similar subsidies as offshore wind farms that produce only electricity could facilitate further cost reduction. Utilizing excess and intermittent offshore wind highlights one possible pathway that could achieve increasing returns on greenhouse gas emission reductions due to technological learning in hydrogen production, even under conditions where low power prices make offshore wind less competitive in the European electricity market.     

Decomposition analysis of CO2 emissions from electricity generation in China

Electricity generation in China mainly depends on coal and its products, which has led to the increase in CO₂ emissions. This paper intends to analyze the current status of CO₂ emissions from electricity generation in China during the period 1991–2009, and apply the logarithmic mean Divisia index (LMDI) technique to find the nature of the factors influencing the changes in CO₂ emissions. The main results as follows: (1) CO₂ emission from electricity generation has increased from 530.96 Mt in 1991 to 2393.02 Mt in 2009, following an annual growth rate of 8.72%. Coal products is the main fuel type for thermal power generation, which accounts for more than 90% CO₂ emissions from electricity generation. (2) This paper also presents CO₂ emissions factor of electricity consumption, which help calculate CO₂ emission from final electricity consumption. (3) In China, the economic activity effect is the most important contributor to increase CO₂ emissions from electricity generation, but the electricity generation efficiency effect plays the dominant role in decreasing CO₂ emissions.     

Factors influencing CO2 emissions in China's power industry: Co-integration analysis

More than 40% of China's total CO₂ emissions originate from the power industry. The realization of energy saving and emission reduction within China's power industry is therefore crucial in order to achieve CO₂ emissions reduction in this country. This paper applies the autoregressive-distributed lag (ARDL) co-integration model to study the major factors which have influenced CO₂ emissions within China's power industry from 1980 to 2010. Results have shown that CO₂ emissions from China's power industry have been increasing rapidly. From 1980 to 2010, the average annual growth rate was 8.5%, and the average growth rate since 2002 has amounted to 10.5%. Secondly, the equipment utilization hour (as an indicator of the power demand) has the greatest influence on CO₂ emissions within China's power industry. In addition, the impact of the industrial added value of the power sector on CO₂ emissions is also positive from a short-term perspective. Thirdly, the Granger causality results imply that one of the important motivators behind China's technological progress, within the power industry, originates from the pressures created by a desire for CO₂ emissions reduction. Finally, this paper provides policy recommendations for energy saving and emission reduction for China's power industry.     

Energy efficiency,CO2 emission performance and technology gaps in fossil fuel electricity generation in Korea: A meta-frontier non-radial directional distance functionanalysis

This paper proposes a meta-frontier non-radial directional distance function to model energy and CO₂ emission performance in electricity generation. This approach allows for the consideration of the group heterogeneity of electricity generation, non-radial slacks, and undesirable outputs simultaneously. We extend several standardized indices to measure total-factor energy efficiency, CO₂ emission performance, and technology gaps in electricity generation. We estimate the potential reductions in energy use and CO₂ emissions under different technology assumptions. We conduct an empirical analysis of fossil fuel electricity generation in Korea by using the proposed approach. The results indicate that coal-fired power plants show higher levels of total-factor energy efficiency and CO₂ emission performance than oil-fired ones. Under the meta-frontier technology assumption, coal-fired power plants show a smaller technology gap than oil-fired ones. This suggests that the Korean government should promote technological innovation to reduce technology gaps for oil-fired plants, thereby improving energy and CO₂ emission performance and meeting emission reduction targets in the electricity generation industry.     

Supply- and demand-side effects of power sector planning with CO2 mitigation constraints in a developing country

In this paper, the implications of CO₂ emission mitigation constraints in the power sector planning in Indonesia are examined using a long term integrated resource planning model. An approach is developed to assess the contributions of supply- and demand-side effects to the changes in CO₂, SO₂ and NO_x emissions from the power sector due to constraints on CO₂ emissions. The results show that while both supply- and demand-side effects would act towards the reduction of CO₂, SO₂ and NO_x emissions, the supply-side options would play the dominant role in emission mitigations from the power sector in Indonesia. The CO₂ abatement cost would increase from US$7.8 to US$9.4 per ton of CO₂, while the electricity price would increase by 3.1 to 19.8% if the annual CO₂ emission reduction target is raised from 10 to 25%.     

Power sector development in India with CO2 emission targets: Effects of regional grid integration and the role of clean technologies

The power sector in India at present comprises of five separate regional electricity grids having practically no integrated operation in between them. This study analyses the utility planning, environmental and economical effects of integrated power sector development at the national level in which the regional electric grids are developed and operated as one integrated system. It also examines the effects of selected CO₂ emission reduction targets in the power sector and the role of renewable power generation technologies in India. The study shows that the integrated development and operation of the power system at the national level would reduce the total cost including fuel cost by 4912 million $, total capacity addition by 2784 MW, while the emission of CO₂, SO₂ and NO_x would be reduced by 231.6 (1.9%), 0.8 (0.9%), 0.4 (1.2%) million tons, respectively, during the planning horizon. Furthermore, the study shows that the expected unserved energy, one of the indices of generation system reliability, would decrease to 26 GWh under integrated national power system from 5158 GWh. As different levels of CO₂ emission reduction targets were imposed, there is a switching of generation from conventional coal plants to gas fired plants, clean coal technologies and nuclear based plants. As a result the capacity expansion cost has increased. It was found that wind power plant is most attractive and economical in the Indian perspective among the renewable options considered (Solar, wind and biomass). Copyright © 2003 John Wiley & Sons, Ltd.     

Evaluating carbon dioxide emissions in international trade of China

China is the world's largest emitter of carbon dioxide (CO₂). As exports account for about one-third of China's GDP, the CO₂ emissions are related to not only China's own consumption but also external demand. Using the input–output analysis (IOA), we analyze the embodied CO₂ emissions of China's import and export. Our results show that about 3357 million tons CO₂ emissions were embodied in the exports and the emissions avoided by imports (EAI) were 2333 million tons in 2005. The average contribution to embodied emission factors by electricity generation was over 35%. And that by cement production was about 20%. It implies that the production-based emissions of China are more than the consumption-based emissions, which is evidence that carbon leakage occurs under the current climate policies and international trade rules. In addition to the call for a new global framework to allocate emission responsibilities, China should make great efforts to improve its energy efficiency, carry out electricity pricing reforms and increase renewable energy. In particular, to use advanced technology in cement production will be helpful to China's CO₂ abatement.     

Potential for reducing global carbon emissions from electricity production—A benchmarking analysis

We present five performance indicators for electricity generation for 129 countries using the 2005 data. These indicators, measured at the national level, are the aggregate CO₂ intensity of electricity production, the efficiencies of coal, oil and gas generation and the share of electricity produced from non-fossil fuels. We conduct a study on the potential for reducing global energy-related CO₂ emissions from electricity production through simple benchmarking. This is performed based on the last four performance indicators and the construction of a cumulative curve for each of these indicators. It is found that global CO₂ emissions from electricity production would be reduced by 19% if all these indicators are benchmarked at the 50th percentile. Not surprisingly, the emission reduction potential measured in absolute terms is the highest for large countries such as China, India, Russia and the United States. When the potential is expressed as a percentage of a country's own emissions, few of these countries appear in the top-five list.     

Wind power planning: assessing long-term costs and benefits

In the following paper, a new and straightforward technique for estimating the social benefit of large-scale wind power production is presented. The social benefit is based upon wind power's energy and capacity services and the avoidance of environmental damages. The approach uses probabilistic load duration curves to account for the stochastic interaction between wind power availability, electricity demand, and conventional generator dispatch. The model is applied to potential offshore wind power development to the south of Long Island, NY. If natural gas combined cycle and integrated gasifier combined cycle (IGCC) are the alternative generation sources, wind power exhibits a negative social benefit due to its high capacity cost and the relatively low emissions of these advanced fossil-fuel technologies. Environmental benefits increase significantly if charges for CO₂ emissions are included. Results also reveal a diminishing social benefit as wind power penetration increases. The dependence of wind power benefits on CO₂ charges, and capital costs for wind turbines and IGCC plant is also discussed. The methodology is intended for use by energy planners in assessing the social benefit of future investments in wind power.     

Wind power and CO2 emissions in the Irish market

This paper presents an empirical analysis of the displacement of CO₂ emissions associated with wind generation in the Irish electricity market between December 2013 and May 2017. We find that the average marginal effect of an additional MWh of wind generation corresponds to a reduction in CO₂ emissions of 0.401 tonnes in Ireland (All-Island system) and 0.459 tonnes when accounting also for the emissions offset in Great Britain. We also find that, for each given demand level, the amount of emissions displaced by wind varies with the wind level. In particular, overall the amount of total (domestic plus external) CO₂ emissions offset by a MWh of wind generation increases as the wind generation level increases, a result which suggests that as wind generation capacity increases the effectiveness of wind in displacing CO₂ may be retained. However, when accounting exclusively for the effects of wind generation on domestic emissions, we observe that the effectiveness of wind in displacing emissions may decrease as the amount of wind generation increases further. As the effects of CO₂ as a GHG are independent of the location where it is emitted, our work also highlights that accounting for reductions in emissions due to a reduction of imports from, or an increase in exports to, interconnected markets is crucial in this type of analysis due to the potential for underestimating the effects of wind on emissions savings when only national emissions are accounted for. The Irish government has a target for 40% of total electricity generation to be produced by renewable energy sources by 2020 which, according to institutional reports, may entail an additional 25% to 35% increase in wind generation capacity from the present levels. Accordingly, our findings are particularly relevant for policy making since they do not support one of the arguments against further investment in wind, namely that the corresponding environmental benefits in the form of emissions savings are reduced.     

A regional analysis of carbon intensities of electricity generation in China

Index decomposition analysis (IDA) has been widely applied to study CO₂ emissions from electricity generation. However, most have focused on emissions at the country level, less attention has been given to emissions at the regional level. To fill the gap, this study firstly utilized a Logarithmic Mean Divisia Index (LMDI) method to analyze the driving forces of aggregate carbon intensity (ACI) of electricity generation in China from 2000 to 2014. A regional attribution analysis was introduced to look into the contributions from 30 provinces to the driving forces. Then, a multi-regional spatial-IDA was further adopted to assess the emission performance of electricity generation in 30 provinces. The results of temporal-IDA and regional attribution analysis show that the ACI in China dropped notably by 14.5% from 2000 to 2014. Thermal efficiency improvement was a major driver for the decrease, due largely to the significant improvement in thermal generation efficiency in the eastern coastal regions. Clean power penetration reduced ACI remarkably as well, of which the western regions were the main contributors. The spatial-IDA results indicate that the emission performance of electricity generation in different regions varied significantly. While the western regions performed better in clean power penetration, the eastern regions performed better in thermal generation efficiency. Based on the findings, several regional policy strategies were recommended to further lower down ACI of electricity in China.     

Reduction of air pollutant emissions using renewable energy sources for power generation in Cyprus

In this paper, the options of using Renewable Energy Sources (RES) in the power system of Cyprus are examined in order to reduce air pollutant emissions. Power generation is the major contributor to total emissions in Cyprus with a share of 36% in carbon dioxide (CO₂), 62% in sulfur dioxide (SO₂), 20% in nitrogen oxides (NO_x) and 55% in nitrous oxide (N₂O) emission according to the emission inventory for the year 2002. The emissions reduction potential in the energy system of Cyprus is notable since the use of RES for power generation has so far been negligible. The national action plan for the promotion of electricity production from RES for the years 2009–2013 includes large-scale projects of total capacity target 211 MW_el, and in case is accomplished, there will be significant production of electricity, which is estimated to 11.2% of 2008 gross production. The resulting reduction of air pollutant emissions corresponds to 453 kt/yr of CO₂, 4.69 kt/yr of SO₂, 1.21 kt/yr of NO_x, 0.26 kt/yr of N₂O emissions and exceeds the emissions of Moni power station, the oldest in Cyprus and the one with the lower efficiency. Emissions reduction potential is even larger, since additional measures for rational use of electricity together with RES applications in final consumption sectors could contribute to decrease the demanded amount of electricity.     

CO2 emission and avoidance in mobile applications

The present paper analyzes the CO₂ emissions from mobile communications and portable wireless electronic devices in the Korea environment. The quantitative and qualitative contributions to CO₂ emission reduction of the substitution of renewable energy for traditional electricity as the power supply in these devices are also investigated.Firstly, the national CO₂ emission coefficient is temporarily estimated as 0.504 tCO₂/MWh, which can be regarded as the basis for calculating CO₂ emissions in mobile devices. The total annual CO₂ emissions from mobile devices is calculated as approximately 1.4 million tons, comprising 0.3 million tCO₂ for portable wireless electronic devices and 1.1 million tCO₂ for electric equipment required for mobile communication service.If renewable energy sources are substituted for traditional electricity sources in the supply for mobile devices, solar cell and wind turbine systems can reduce CO₂ emissions by about 87% and 97%, respectively. However, the use of fuel cell systems will only slightly reduce the CO₂ emissions. However, the use of the direct methanol fuel cell system can release 8% more CO₂ emissions than that emitted by using traditional electricity sources.     

Price determination of ETS allowances through the switching level of coal and gas in the power sector

This paper discusses the opportunities that exist for reducing greenhouse gases (GHG) emissions by switching from coal to gas‐fired units in electricity generation, ‘forced’ by the European Union Greenhouse Gas Emission Trading Scheme (EU ETS) price level of CO₂. It attempts to find efficient GHG cost profiles leading to a reasonable GHG emission reduction. In a methodological demonstration case (an electricity generation system consisting of two coal and two gas‐fired power plants), we demonstrate how a GHG emission cost can lead to a certain switch of power plants with an accompanying GHG emission reduction. This GHG emission cost is dependent on the load level. The switching point method is applied to an electricity generation system similar to the Belgian one. It is found that the greatest opportunities for GHG emission reductions are situated in the summer season. By switching only the coal‐fired units with the combined cycle (CC) gas‐fired units, a significant GHG emission reduction is possible at a modest cost. With the simulation tool E‐Simulate, the effect of a GHG emission cost in the summer season is investigated. A potential GHG emission reduction of 9.5% in relation to the case where there is no cost linked to GHG emission is possible at a relative low cost. When implementing a GHG cost in winter season, a smaller GHG reduction occurs while costs are higher. Copyright © 2006 John Wiley & Sons, Ltd.     

Examining the driving forces for improving China’s CO2 emission intensity using the decomposing method

This paper examines the driving forces for reducing China’s CO₂ emission intensity between 1998 and 2008, utilizing the logarithmic mean divisia index (LMDI) technique. By first grouping the CO₂ emissions into two categories, those arising from activities related to the electric power industry and those from other sources, emission intensity is further broken down into the effects of the CO₂ emission coefficient, energy intensity of power generation, power generation and consumption ratio, electricity intensity of the gross domestic product (GDP), provincial structural change, and the energy intensity of the GDP for other activities. The decomposition results show that improvements in the energy intensity of power generation, electricity intensity of GDP, and energy intensity of GDP for other activities were mainly responsible for the success in reducing China’s CO₂ emission intensity and that activities related to the electric power industry played a key role. It is also revealed that performance varied significantly at the individual province level. The provinces with higher emission levels contributed the most to China’s improvements in CO₂ emission intensity.     

Carbon dioxide emission from the Turkish electricity sector and its mitigation options

In this study, electricity generation associated CO₂ emissions and fuel-specific CO₂ emission factors are calculated based on the IPCC methodology using the data of fossil-fueled power plants that ran between 2001 and 2008 in Turkey. The estimated CO₂ emissions from fossil-fueled power plants between 2009 and 2019 are also calculated using the fuel-specific CO₂ emission factors and data on the projected generation capacity of the power plants that are planned to be built during this period. Given that the total electricity supply (planned+existing) will not be sufficient to provide the estimated demand between 2011 and 2019, four scenarios based on using different fuel mixtures are developed to overcome this deficiency. The results from these scenarios show that a significant decrease in the amount of CO₂ emissions from electricity generation can be achieved if the share of the fossil-fueled power plants is lowered. The Renewable Energy Scenario is found to result in the lowest CO₂ emissions between 2009 and 2019. The associated CO₂ emissions calculated based on this scenario are approximately 192 million tons lower than that of the Business As Usual Scenario for the estimation period.