Consequential environmental system analysis of expected offshore wind electricity production in Germany

Taking advantage of offshore wind power appears to be of special significance for the climate protection plans announced by the German Federal Government. For this reason, a comprehensive system analysis of the possible CO₂ reduction including the consideration of all relevant processes has to be performed. This goal can be achieved by linking a life-cycle assessment model of offshore wind utilisation with a stochastic model of the German electricity market. Such an extended life-cycle assessment shows that the CO₂ emissions from the construction and operation of wind farms are low compared with the substitution effects of fossil fuels. Additionally, in the German electricity system, offshore wind energy is the main substitute for medium-load power plants. CO₂ emissions from the modified operation and the expansion of conventional power plants reduce the CO₂ savings, but the substitution effect outweighs these emissions by one order of magnitude. The assumptions of the model, shown here to be above all CO₂ certificate prices, have a considerable influence on the figures shown due to a significant effect on the future energy mix.     

Effects on global CO<Subscript>2</Subscript> emissions when substituting LPG with bio-SNG as fuel in steel industry reheating furnaces—the impact of different perspectives on CO<Subscript>2</Subscript> assessment

The iron and steel industry is the second largest user of energy in the world industrial sector and is currently highly dependent on fossil fuels and electricity. Substituting fossil fuels with renewable energy in the iron and steel industry would make an important contribution to the efforts to reduce emissions of CO₂. However, different approaches to assessing CO₂ emissions from biomass and electricity use generate different results when evaluating how fuel substitution would affect global CO₂ emissions. This study analyses the effects on global CO₂ emissions when substituting liquefied petroleum gas with synthetic natural gas, produced through gasification of wood fuel, as a fuel in reheating furnaces at a scrap-based steel plant. The study shows that the choice of system perspective has a large impact on the results. When wood fuel is considered available for all potential users, a fuel switch would result in reduced global CO₂ emissions. However, applying a perspective where wood fuel is seen as a limited resource and alternative use of wood fuel is considered, a fuel switch could in some cases result in increased global CO₂ emissions. As an example, in one of the scenarios studied, a fuel switch would reduce global CO₂ emissions by 52 ktonnes/year if wood fuel is considered available for all potential users, while seeing wood fuel as a limited resource implies, in the same scenario, increased CO₂ emissions by 70 ktonnes/year. The choice of method for assessing electricity use also affects the results.     

Evaluation of lifecycle CO2 emissions from the Japanese electric power sector in the 21st century under various nuclear scenarios

The status and prospects of the development of Japanese nuclear power are controversial and uncertain. Many deem that nuclear power can play key roles in both supplying energy and abating CO₂ emissions; however, due to severe nuclear accidents, public acceptance of nuclear power in Japan has not been fully obtained. Moreover, deregulation and liberalization of the electricity market impose pressure on large Japanese electric power companies with regard to both the operation of nuclear power plants and the development of the nuclear fuel cycle. Long-term Japanese CO₂ reduction strategies up to 2100 are of environmental concern and are socially demanded under the circumstances described above. Taking these factors into account, we set the following two objectives for this study. One is to estimate lifecycle CO₂ (LCCO₂) emissions from Japanese nuclear power, and the other is to evaluate CO₂ emissions from the Japanese electric power sector in the 21st century by quantifying the relationship between LCCO₂ emissions and scenarios for the adoption of nuclear power. In the pursuit of the above objectives, we first create four scenarios of Japanese adoption of nuclear power, that range from nuclear power promotion to phase-out. Next, we formulate four scenarios describing the mix of the total electricity supply in Japan till the year 2100 corresponding to each of these nuclear power scenarios. CO₂ emissions from the electric power sector in Japan till the year 2100 are estimated by summing those generated by each respective electric power technology and LCCO₂ emission intensity. The LCCO₂ emission intensity of nuclear power for both light water reactors (LWR) and fast breeder reactors (FBR) includes the uranium fuel production chain, facility construction/operation/decommission, and spent fuel processing/disposal. From our investigations, we conclude that the promotion of nuclear power is clearly a strong option for reducing CO₂ emissions by the electric power sector. The introduction of FBR has the effect of further reducing CO₂ emissions in the nuclear power sector. Meeting energy demand and reducing CO₂ emissions while phasing out nuclear power appears challenging given its importance in the Japanese energy supply.     

Grey relation performance correlations among economics,energy use and carbon dioxide emission in Taiwan

This study explores the inter-relationships among economy, energy and CO₂ emissions of 37 industrial sectors in Taiwan in order to provide insight regarding sustainable development policy making. Grey relation analysis was used to analyse the productivity, aggregate energy consumption, and the use of fuel mix (electricity, coal, oil and gas) in relation to CO₂ emission changes. An innovative evaluative index system was devised to explore grey relation grades among economics, energy and environmental quality. Results indicate that a rapid increase in electricity generation during the past 10 years is the main reason for CO₂ emission increase in Taiwan. The largest CO₂ emitting sectors include iron and steel, transportation, petrochemical materials, commerce and other services. Therefore, it is important to reduce the energy intensity of these sectors by energy conservation, efficiency improvement and adjustment of industrial structure towards high value-added products and services. Economic growth for all industries has a more significant influence, than does total energy consumption, on CO₂ emission increase in Taiwan. It is also important to decouple the energy consumption and production to reduce the impacts of CO₂ on economic growth. Furthermore, most of the sectors examined had increased CO₂ emissions, except for machinery and road transportation. For high energy intensive and CO₂ intensive industries, governmental policies for CO₂ mitigation should be directed towards low carbon fuels as well as towards enhancement of the demand side management mechanism, without loss of the nation's competitiveness.     

Electricity savings and CO2 emissions reduction in buildings sector: How important the network losses are in the calculation?

The increase of CO₂ emissions and the emerging climate change are the most serious environmental problems nowadays and limit economic development. This increase is mainly attributed to the growing world population and the related growth in energy demand, which results in the vast consumption of fossil fuels in the power generation sector. Significant actions for the implementation of energy saving measures have been adopted worldwide for reducing greenhouse gas emissions. CO₂ calculators have been developed to evaluate the effectiveness of these measures, relating energy to CO₂ emissions. These calculators include in most cases the entire power system. The purpose of this work was to evaluate the role of the electricity networks' losses in the actual CO₂ reduction potential, following the implementation of energy saving measures, in relation to the network's voltage level in which the infrastructure is connected. Buildings are representative due to their volume and to different voltage levels of power supply. The work presented was conducted in the framework of the Intelligent Energy Europe Programme entitled Bottom Up to Kyoto (BUtK), as a part of an evaluation of the CO₂ emissions' reduction potential through energy savings measures in 6 municipalities of EU's New Member States.     

Modeling China’s energy dilemma: conflicts among energy saving, energy security, and CO2 mitigation

This study analyzes China’s future energy scenarios stretching until 2050 under different policy portfolios of energy security (e.g., oil import dependency) and CO₂ emissions control. Four scenarios, namely, ① business as usual, ② strong oil import dependency (OID) control, ③ strong CO₂ emissions control, and ④ twofold emphasis on OID and CO₂ emissions control, are designed. The results reveal the existence of conflicts among China’s multiple objectives, particularly energy saving, energy security, and CO₂ mitigation. Based on the analysis, an improvement in China’s efficiency in fossil energy conversion and the promotion of the utilization of non-fossil energy such as nuclear, wind, and hydro energy are recommended. The over-development of coal-derived fuels should also be avoided because of incremental coal consumption and CO₂ emissions. Furthermore, research on and development of carbon capture and storage technologies should be promoted, while the energy efficiency loss caused by integrating these technologies into energy systems should be reduced in view of the high possibility of stricter standards for CO₂ emissions in the future.     

Modeling China’s energy dilemma: conflicts among energy saving,energy security,and CO<Subscript>2</Subscript> mitigation

This study analyzes China’s future energy scenarios stretching until 2050 under different policy portfolios of energy security (e.g., oil import dependency) and CO₂ emissions control. Four scenarios, namely, ① business as usual, ② strong oil import dependency (OID) control, ③ strong CO₂ emissions control, and ④ twofold emphasis on OID and CO₂ emissions control, are designed. The results reveal the existence of conflicts among China’s multiple objectives, particularly energy saving, energy security, and CO₂ mitigation. Based on the analysis, an improvement in China’s efficiency in fossil energy conversion and the promotion of the utilization of non-fossil energy such as nuclear, wind, and hydro energy are recommended. The over-development of coal-derived fuels should also be avoided because of incremental coal consumption and CO₂ emissions. Furthermore, research on and development of carbon capture and storage technologies should be promoted, while the energy efficiency loss caused by integrating these technologies into energy systems should be reduced in view of the high possibility of stricter standards for CO₂ emissions in the future.     

Energy and environmental issues relating to greenhouse gas emissions for sustainable development in Turkey

Turkey's demand for energy and electricity is increasing rapidly. Since 1990, energy consumption has increased at an annual average rate of 4.3%. As would be expected, the rapid expansion of energy production and consumption has brought with it a wide range of environmental issues at the local, regional and global levels. With respect to global environmental issues, Turkey's carbon dioxide (CO₂) emissions have grown along with its energy consumption. Emissions in 2004 reached 193 million tons. States have played a leading role in protecting the environment by reducing emissions of greenhouse gases (GHGs). State emissions are significant on a global scale. CO₂ and carbon monoxide (CO) are the main GHGs associated with global warming. At the present time, coal is responsible for 30–40% of the world CO₂ emissions from fossil fuels. Sulfur dioxide (SO₂) and NO_x contribute to acid rain. Carbon assessments can play an important role in a strategy to control CO₂ emissions while raising revenue.     

Life cycle assessment of electricity generation in Mexico

This paper presents for the first time a Life Cycle Assessment (LCA) study of electricity generation in Mexico. The electricity mix in Mexico is dominated by fossil fuels, which contribute around 79% to the total primary energy; renewable energies contribute 16.5% (hydropower 13.5%, geothermal 3% and wind 0.02%) and the remaining 4.8% is from nuclear power. The LCA results show that 225 TWh of electricity generate about 129 million tonnes of CO₂ eq. per year, of which the majority (87%) is due to the combustion of fossil fuels. The renewables and nuclear contribute only 1.1% to the total CO₂ eq. Most of the other LCA impacts are also attributed to the fossil fuel options. The results have been compared with values reported for other countries with similar electricity mix, including Italy, Portugal and the UK, showing good agreement.     

Improving the technical, environmental and social performance of wind energy systems using biomass-based energy storage

A completely renewable baseload electricity generation system is proposed by combining wind energy, compressed air energy storage, and biomass gasification. This system can eliminate problems associated with wind intermittency and provide a source of electrical energy functionally equivalent to a large fossil or nuclear power plant. Compressed air energy storage (CAES) can be economically deployed in the Midwestern US, an area with significant low-cost wind resources. CAES systems require a combustible fuel, typically natural gas, which results in fuel price risk and greenhouse gas emissions. Replacing natural gas with synfuel derived from biomass gasification eliminates the use of fossil fuels, virtually eliminating net CO₂ emissions from the system. In addition, by deriving energy completely from farm sources, this type of system may reduce some opposition to long distance transmission lines in rural areas, which may be an obstacle to large-scale wind deployment.     

Estimation of the potential for reduced greenhouse gas emission in North-East Russia: A comparison of energy use in mining,mineral processing and residential heating in Kiruna and Kirovsk-Apatity

The energy demand at Murmansk Oblast in North-East Russia is covered at 60% by fossil fuels and at 40% by electricity. This study estimates the potential for reduction of fossil fuel consumption and CO₂-emissions at Murmansk Oblast. The study focus on the municipalities of Apatity and Kirovsk and the apatite ore mining company Apatit JSC . The potential for energy efficiency, reduced fossil fuel consumption and greenhouse gas emissions is estimated by comparison with the of city Kiruna in Northern Sweden, with a climate similar to that of North-East Russia, and with the iron ore mining company LKAB. This study shows that the potential for reduced CO₂-emissions is about 630,700 tons CO₂ annually in the municipalities of Apatity and Kirovsk or 6.3 tons of CO₂ per capita, Apatit JSC not included. These results applied on Murmansk Oblast gives a potential for reduced CO₂-emissions of about 6 Mtons annually in the municipalities together. The specific energy consumption at Apatit JSC is 6–7 times per ton product compared to LKAB. The mining has 4 times higher specific energy consumption per ton raw ore compared to LKAB.     

Emissions reduction scenarios in the Argentinean Energy Sector

In this paper the LEAP, TIAM-ECN, and GCAM models were applied to evaluate the impact of a variety of climate change control policies (including carbon pricing and emission constraints relative to a base year) on primary energy consumption, final energy consumption, electricity sector development, and CO₂ emission savings of the energy sector in Argentina over the 2010–2050 period. The LEAP model results indicate that if Argentina fully implements the most feasible mitigation measures currently under consideration by official bodies and key academic institutions on energy supply and demand, such as the ProBiomass program, a cumulative incremental economic cost of 22.8 billion US$(2005) to 2050 is expected, resulting in a 16% reduction in GHG emissions compared to a business-as-usual scenario. These measures also bring economic co-benefits, such as a reduction of energy imports improving the balance of trade. A Low CO₂ price scenario in LEAP results in the replacement of coal by nuclear and wind energy in electricity expansion. A High CO₂ price leverages additional investments in hydropower. By way of cross-model comparison with the TIAM-ECN and GCAM global integrated assessment models, significant variation in projected emissions reductions in the carbon price scenarios was observed, which illustrates the inherent uncertainties associated with such long-term projections. These models predict approximately 37% and 94% reductions under the High CO₂ price scenario, respectively. By comparison, the LEAP model, using an approach based on the assessment of a limited set of mitigation options, predicts an 11.3% reduction. The main reasons for this difference include varying assumptions about technology cost and availability, CO₂ storage capacity, and the ability to import bioenergy. An emission cap scenario (2050 emissions 20% lower than 2010 emissions) is feasible by including such measures as CCS and Bio CCS, but at a significant cost. In terms of technology pathways, the models agree that fossil fuels, in particular natural gas, will remain an important part of the electricity mix in the core baseline scenario. According to the models there is agreement that the introduction of a carbon price will lead to a decline in absolute and relative shares of aggregate fossil fuel generation. However, predictions vary as to the extent to which coal, nuclear and renewable energy play a role.     

China's transportation energy consumption and CO2 emissions from a global perspective

Rapidly growing energy demand from China's transportation sector in the last two decades have raised concerns over national energy security, local air pollution, and carbon dioxide (CO₂) emissions, and there is broad consensus that China's transportation sector will continue to grow in the coming decades. This paper explores the future development of China's transportation sector in terms of service demands, final energy consumption, and CO₂ emissions, and their interactions with global climate policy. This study develops a detailed China transportation energy model that is nested in an integrated assessment model—Global Change Assessment Model (GCAM)—to evaluate the long-term energy consumption and CO₂ emissions of China's transportation sector from a global perspective. The analysis suggests that, without major policy intervention, future transportation energy consumption and CO₂ emissions will continue to rapidly increase and the transportation sector will remain heavily reliant on fossil fuels. Although carbon price policies may significantly reduce the sector's energy consumption and CO₂ emissions, the associated changes in service demands and modal split will be modest, particularly in the passenger transport sector. The analysis also suggests that it is more difficult to decarbonize the transportation sector than other sectors of the economy, primarily owing to its heavy reliance on petroleum products.     

Long-term trends of electric efficiencies in electricity generation in developing countries

This analysis provides time-series data on electric efficiencies for 138 countries and regions, covering all fossil fuels for the period 1971–2005, with an emphasis on non-Organization for Economic Cooperation and Development (OECD) countries. Fossil fuel consumption for electricity generation in non-OECD countries now exceeds that in the OECD. The historical performance of the top five non-OECD consumers of each fossil fuel for which reliable data are available is presented and discussed. For each fuel, the countries that lead the world in efficiency are used for benchmarks; bringing the rest of the world up to these standards would result in energy savings of 26 EJ (equivalent to 5% of global energy consumption) and CO₂ emissions reduction of 2.1 Pg (equivalent to 8% of global CO₂ emissions). Coal showed the largest potential margin of improvement for both energy and CO₂, with possible savings equivalent to 3% of current global energy consumption and 5% of global CO₂ emissions. The gap in electric efficiency between OECD and non-OECD countries over the past 35 years has widened for coal-fired generation, stayed relatively constant for natural gas, but has shrunk for petroleum. The results show the very gradual nature of overall efficiency improvements and the significant differences among regions and countries.     

US biofuels subsidies and CO2 emissions: An empirical test for a weak and a strong green paradox

Using energy data over the period 1981–2011 we find that US biofuels subsidies and production have provided a perverse incentive for US fossil fuel producers to increase their rate of extraction that has generated a weak green paradox. Further, in the short-run if the reduction in the CO₂ emissions from a one-to-one substitution between biofuels and fossil fuels is less than 26 percent, or less than 57 percent if long run effect is taken into account, then US biofuels production is likely to have resulted in a strong green paradox. These results indicate that subsidies for first generation biofuels, which yield a low level of per unit CO₂ emission reduction compared to fossil fuels, might have contributed to additional net CO₂ emissions over the study period.     

Reduction of electricity use in Swedish industry and its impact on national power supply and European CO2 emissions

Decreased energy use is crucial for achieving sustainable energy solutions. This paper presents current and possible future electricity use in Swedish industry. Non-heavy lines of business (e.g. food, vehicles) that use one-third of the electricity in Swedish industry are analysed in detail. Most electricity is used in the support processes pumping and ventilation, and manufacturing by decomposition. Energy conservation can take place through e.g. more efficient light fittings and switching off ventilation during night and weekends. By energy-carrier switching, electricity used for heat production is replaced by e.g. fuel. Taking technically possible demand-side measures in the whole lines of business, according to energy audits in a set of factories, means a 35% demand reduction. A systems analysis of power production, trade, demand and conservation was made using the MODEST energy system optimisation model, which uses linear programming and considers the time-dependent impact on demand for days, weeks and seasons. Electricity that is replaced by district heating from a combined heat and power (CHP) plant has a dual impact on the electricity system through reduced demand and increased electricity generation. Reduced electricity consumption and enhanced cogeneration in Sweden enables increased electricity export, which displaces coal-fired condensing plants in the European electricity market and helps to reduce European CO₂ emissions. Within the European emission trading system, those electricity conservation measures should be taken that are more cost-efficient than other ways of reducing CO₂ emissions. The demand-side measures turn net electricity imports into net export and reduce annual operation costs and net CO₂ emissions due to covering Swedish electricity demand by 200 million euros and 6 Mtonne, respectively. With estimated electricity conservation in the whole of Swedish industry, net electricity exports would be larger and net CO₂ emissions would be even smaller.     

Status of thermal power generation in India—Perspectives on capacity,generation and carbon dioxide emissions

India’s reliance on fossil-fuel based electricity generation has aggravated the problem of high carbon dioxide (CO₂) emissions from combustion of fossil fuels, primarily coal, in the country’s energy sector. The objective of this paper is to analyze thermal power generation in India for a four-year period and determine the net generation from thermal power stations and the total and specific CO₂ emissions. The installed generating capacity, net generation and CO₂ emissions figures for the plants have been compared and large generators, large emitters, fuel types and also plant vintage have been identified. Specific emissions and dates of commissioning of plants have been taken into account for assessing whether specific plants need to be modernized. The focus is to find out areas and stations which are contributing more to the total emissions from all thermal power generating stations in the country and identify the overall trends that are emerging.     

Long term climate change mitigation goals under the nuclear phase out policy: The Swiss energy system transition

The Swiss electricity system is dominated by low-carbon hydro and nuclear generation. The Government's decision to phase-out nuclear energy exacerbates Switzerland's climate change mitigation goals. Response to this challenge requires systemic changes to the energy system, which is generally a long-term, uncertain and systemic process, affected by technology choices across the entire energy system. A comprehensive Swiss TIMES Energy system Model (STEM) with high temporal detail has been developed for the analysis of plausible low-carbon energy pathways focusing on uncertainties related to policy (climate change mitigation and acceptability of new centralised electricity generation) and international fuel prices. Increasing electrification of end-uses is seen across the scenarios, resulting in continuous growth in electricity demands. The electrification of heating and e-mobility substitute direct use of fossil fuels in end-use sectors and contribute to a significant carbon dioxide emission (CO₂) reduction. Centralised gas power plants and renewables become key source of electricity supply. Given the phaseout of nuclear generation, clear policy signals are required to ensure capacity is built to achieve a low-carbon energy system. At the same time, it is also essential to ensure consistency between the electricity sector and end-use energy policies. For the long-term carbon reduction target, some non-cost-effective conservation measures are important early in the period because they are available only at the time of building renovation.     

Efficiency assessment of indoor environmental policy for air-conditioned offices in Hong Kong

To reduce carbon dioxide (CO₂) emissions through thermal energy conservation, air-conditioned offices in the subtropics are recommended to operate within specified ranges of indoor temperature, relative humidity and air velocity. As thermal discomfort leads to productivity loss, some indoor environmental policies for air-conditioned offices in Hong Kong are investigated in this study with relation to thermal energy consumption, CO₂ emissions from electricity use, and productivity loss due to thermal discomfort. Occupant thermal response is specifically considered as an adaptive factor in evaluating the energy consumption and productivity loss. The energy efficiency of an office is determined by the productivity which corresponds to the CO₂ generated. The results found that a policy with little impact on occupant thermal comfort and worker productivity would improve the office efficiency while the one with excessive energy consumption reduction would result in a substantial productivity loss. This study is a useful reference source for evaluating an indoor thermal environmental policy regarding the energy consumption, CO₂ emissions reduction, thermal comfort and productivity loss in air-conditioned offices in subtropical areas.     

Environmental impact assessment of green energy systems for power supply of electric vehicle charging station

The Electric Vehicle (EV) as a clean alternative to Classic Vehicle that use fossil fuels is promoted as an immediate solution to improve the quality parameters of the environment related to the transport sector. The transition to clean electrified mobility must be considered from the sustainability spectrum, and the planning of a strategy related to the implementation of electric vehicles implies, from the beginning, providing clean energy conditions to go toward a green-to-green paradigm. It should be noted that the successful implementation of the “green electro mobility” concept depends heavily on the green energy supply solutions of green electric vehicle, so Electric Vehicle Charging Stations (EV-CS) should be powered by electricity generation systems based on green resources. This research article has as main objective the environmental impact assessment from the perspective of CO₂ emissions embedded in green stand-alone energy systems and the estimation of the environmental benefits of their implementation in the power supply of EV-CS from the perspective of avoided CO₂ emissions compared to the classic electricity supply grid. The results indicate that the green energy systems represent feasible solutions for the independent energy support of electric vehicle charging stations, being able to supply electricity based on on-site available 100% alternative energy sources. Related to 1 kWh of electricity, the CO₂ emissions embedded in these systems represent on average 11.40% of the CO₂ emissions of the electricity supplied through the grid at European level and on average 7.10% of the CO₂ emissions of the electricity supplied through the grid worldwide. Results also show that the average price of 1kWh of electricity generated by the analyzed systems is 4.3 times higher than the average unit price of the European Union grid energy, but this indicator must be correlated with the kgCO₂/kWh cost savings compared to the electricity production from classic power plants.