Greenhouse Gas Emissions Calculation Methodology in Thermal Power Plants: Case Study of Iran and Comparison With Canada

In recent years, greenhouse gas (GHG) emissions and their potential effects on the global climate change have been a worldwide concern. Based on International Energy Agency (IEA), power generation contributes half of the increase in global GHG emissions in 2030. In the Middle East, Power generation is expected to make the largest contribution to the growth in carbon-dioxide emissions. The share of the power sector in the region’s total CO2 emissions will increase from 34% in 2003 to 36% in 2030. Therefore, it is very important to reduce GHG emissions in this industry. The purpose of this paper is to examine greenhouse gas emissions reduction potentials in the Iranian electricity generation sector through fuel switching and adoption of advanced power generation systems and to compare these potentials with Canadian electricity generation sector. These two countries are selected because of raw data availability and their unique characteristics in electricity generation sector. To achieve this purpose two different scenarios have been introduced: Scenario #1: Switching existing power stations fuel to natural gas. Scenario #2: Replacing existing power plants by natural gas combined-cycle (NGCC) power stations (The efficiency of NGCC is considered to be 49%). The results shows that the GHG reduction potential for Iranian steam power plants, gas turbines and combined cycle power plants in first scenario are 9.9%, 5.6%, and 2.6%, respectively with the average of 7.6%. For the second scenario the overall reduction of 31.9%, is expected. The average reduction potential for Canadian power plants for scenario number 1 and 2 are 33% and 59%, respectively. As it can be seen, in Canada there are much higher potentials to reduce GHG emissions. The reason is that in Canada majority of power plants use coal as the primary fuel. In fact almost 73% of electricity in thermal power stations is generated by coal. Whereas in Iran almost all power plants (with some exceptions) are dual fuels and 77% of energy consumed in Iran’s thermal power plants come from natural gas. Also, 21% of total electricity generated in Iran is produced by combined-cycle power plants.

Electricity demand in the Islamic Republic of Iran will continue to increase dramatically in the future due to the rapid pace of economic development leading to construction of new power plants. All forms of electricity generation have some level of environmental impact, such as air pollution, water resource use, water discharge, solid waste generation, and land resource use, and greenhouse gas emission. Concerns about greenhouse gas emissions affect decision-making about construction of new power plants. Comparison of different kinds of power plants indicates that nuclear power is not directly emitting greenhouse gas emissions. So nuclear power plants could be a suitable replacement for thermal power plants. Of course, renewable power plants could be used too, but the capacity of nuclear power plants is almost more than renewable power plants. Power plants in Iran are mainly thermal, burning fossil fuels, which emit a great deal of pollutants and greenhouse gases. The only nuclear power plant of Iran (Bushehr nuclear power plant) will be operating in 2009. This article attempts to interpret the role of Bushehr nuclear power plant in the CO2 emission trend of the power plant sector in Iran.

Problem statement: In recent years, Greenhouse Gas (GHG) emissions and their potential effects on global climate change have been a worldwide concern. According to International Energy Agency (IEA), power generation contributes more than half of the global GHG emissions. Approach: Purpose of this study is to examine GHG emission reduction potentials in the Canadian electricity generation sector through fuel switching and adoption of advanced power generation systems. To achieve this objective, eight different scenarios were introduced. In the first scenario, existing power stations’ fuel was switched to natural gas. Existing power plants were replaced by Natural Gas Combined Cycle (NGCC), Integrated Gasification Combined Cycle (IGCC), Solid Oxide Fuel Cell (SOFC), hybrid SOFC and SOFC-IGCC hybrid power stations in scenario numbers 2 to 6, respectively. In last two scenarios, CO2 capture systems were installed in the existing power plants and in the second scenario, respectively. Results: The results showed that Canada’s GHG emissions can be reduced by 33, 59, 20, 64, 69, 29, 86 and 94% based on the first to eighth scenarios, respectively. On the other hand, the second scenario is the most practical and its technology has already matured and is available. In this scenario by replacing existing power plants by NGCC power plants, Canada can fulfill more than 25% of its 238,000 kt year-1 commitment of GHG emission reduction to the Kyoto Protocol. In addition, the GHG emission reduction potentials for each province and Canada as a whole were presented and compared. Based on the results, Alberta, Ontario and Saskatchewan are the biggest producers of GHG in Canada by emitting 49, 21 and 14% of Canada’s GHG emissions, respectively. Therefore, they have higher potential to reduce GHG emissions. The comparison of the results for different provinces revealed that based on efficiency of electricity generation and consumed fuel distribution; specific scenario(s) tend to be suitable for each province. Conclusion: The results pointed out that despite of acceptable performance of some provinces, there are still great potentials to reduce GHG emission level in Canada. In addition, the economical analysis showed that some scenarios are economically competitive with current technologies and should be considered when a new power station is to be built.

Mitigating Curtailment and Carbon Emissions through Load Migration between Data Centers

Modeling of energy consumption and related GHG (greenhouse gas) intensity and emissions in Europe using general regression neural networks

Energy-related activities are a major contributor of greenhouse gas (GHG) emissions. A growing body of knowledge clearly depicts the links between human activities and climate change. Over the last century the burning of fossil fuels such as coal and oil and other human activities has released carbon dioxide (CO2) emissions and other heat-trapping GHG emissions into the atmosphere and thus increased the concentration of atmospheric CO2 emissions. The main human activities that emit CO2 emissions are (1) the combustion of fossil fuels to generate electricity, accounting for about 37% of total U.S. CO2 emissions and 31% of total U.S. GHG emissions in 2013, (2) the combustion of fossil fuels such as gasoline and diesel to transport people and goods, accounting for about 31% of total U.S. CO2 emissions and 26% of total U.S. GHG emissions in 2013, and (3) industrial processes such as the production and consumption of minerals and chemicals, accounting for about 15% of total U.S. CO2 emissions and 12% of total ...

Major US electric utility climate pledges have the potential to collectively reduce power sector emissions by one-third

Advanced bibliometric analysis on the development of natural gas combined cycle power plant with CO2 capture and storage technology

Due to using fossil energy resources, power generation is the most important factor of pollution and greenhouse gas emissions. Considering the importance of the issue, seven scenarios for decreasing greenhouse gas emissions in the power industry, including the development of renewable energies, energy efficiency in thermal power plants, and decreasing the emission of carbon according to international agreements, and the creation of sustainable power generation systems, were defined and evaluated technically, economically, and environmentally. In the current study, an optimization model for long-term power generation planning was used for two concepts of supply and demand. The results of comparing the scenarios showed that the development of renewable power plants was not solely a suitable and optimal way for decreasing greenhouse gas and carbon emissions. The strategies for improving efficiency in thermal power plants, including the development of combined cycle power plants and the repowering of steam power plants, are more suitable options for implementation, considering the constraints of the problem. Therefore, eliminating the existing circumstances and employing the combined scenario while considering the objectives of the study should be the only strategy for decarbonization in this industry, with the minimum cost and minimum rate of emission. By decreasing the share of thermal power plants, decreasing fuel demand, and increasing the share of renewable power plants to 20%, the combined scenario would decrease pollution and greenhouse gas emissions by up to 77.6 million tons of carbon dioxide, as well as the environmental costs up to 1894.5 million dollars, compared to the basic scenario up to 2030. Moreover, paying attention to the management strategies of a demand concept seems necessary from an economic viewpoint, in addition to other presented strategies.

Oil palm (OP) plantations account for 1.7 % of global CO2 emissions. Numerous studies have focused primarily on greenhouse gas (GHG) emissions from peatlands, constituting 20% of total OP area in the two largest OP producing countries, Indonesia and Malaysia. Few studies have investigated the potential for reducing GHG emissions in OP plantations. Strategies to reduce emissions and sequester carbon must consider how different practices affect production and the environment. Understanding the spatial distribution of GHG intensity and how the environment affects GHG intensity is therefore key to sustainable oil palm production.GHG intensity was used as a metric to map the potential for sustainable OP plantations. GHG intensity represents the GHG emissions / removals (ton C ha-1) per unit of oil palm yields (ton ha-1). The approach for analysing the change in GHG emissions/ removals, referred to as the IPCC tier 1 method, is based on changes in soil organic carbon due to C and N emissions in drained peatlands and the associated change in aboveground biomass due to land use change. Changes in GHG intensity were investigated spatially for a case study in an industrial OP plantation located in Riau Province, Indonesia, from 2015 to 2019. Linear regression was used to analyse the relationships between GHG intensity and agri-environmental variables including NDVI, NPP, GPP, evapotranspiration, soil moisture in the root zone, soil moisture in deeper layer, C and N emissions from organic soils, and soil organic carbon (SOC).The results show that around 90% of the new oil palm plantations in 2019 were converted from timber plantation, swamp scrubland, and bare land in 2015. Consequently, biomass growth from land use change acted as a carbon sink in this period. However, drained organic soils contributed significantly to GHG emissions. The change in GHG intensity in OP plantation in this study varied spatially from emitting (0.19 to 4.10 Ton C eq Ton-1 yields) to removing the GHG (0.23 to 2.40 Ton C eq Ton-1 yields). Among the environmental variables, NDVI and soil moisture showed the strongest relationship with GHG emissions/ removals (R2 = 0.23,   p value = < 2.2e-16) and yields (R2 = 0.2   p value = < 2.2e-16) in OP plantations.These initial findings are advantageous for spatially identifying potential OP plantations that remove or emit GHG. Understanding the relationship between GHG emissions/removals and yields to environment variables provides insight into monitoring and enhancing OP sustainability, both from production and environmental perspectives. Future work will examine non-linear approaches to better model this relationship.   

Greenhouse gas emissions from vegetables production in China

The scope of problems connected with the need to continuously improving the consideration of constraints pertinent to development of the power sector and environment protection technologies is outlined. The aim of the study is to assess the contribution of the nuclear power industry in the abatement of greenhouse gas (GHG) emissions. The following has been done in pursuance of this aim: the power generation technologies have been subjected to a comparative analysis in terms of GHG emissions per kW∙h of generated electricity based on a review of large-scale investigations performed around the world, and the abatement of greenhouse gas emissions due to operation of nuclear power plants equipped with VVER-type water-cooled water-moderated power-generating reactors constructed using the technologies developed in Russia (Soviet Union) has been evaluated. Different types of power plants are considered in the investigation in regard of the quantitative characteristics of GHG emissions from the power plants throughout their life cycle (LC) per kilowatt-hour of produced electricity. It should be pointed out that a holistic approach to evaluating the amount of GHG emissions throughout the entire LC of the generation technology including its fuel cycle is of paramount importance, which is substantiated in the relevant ISO and IAEA documents. The study encompasses assessment of hydro- and nuclear power plants, thermal power plants utilizing coal and gas, as well as various renewable energy sources operating on the energy of wind, sun, biomass, and geothermal water. The GHG emissions from NPPs are considered for different power plant LC stages. The article presents the results from calculations of the GHG emissions abatement due to operation of NPPs in Russia and abroad in the period from 1954--2014 for nuclear power plants constructed according to the Russian (Soviet Union's) technologies of VVER-type reactors. The data on the actual amounts of electricity generated at VVER-type NPPs in Armenia, Bulgaria, China, Czech Republic, Finland, Germany, Hungary, India, Iran, Russia, Slovakia, and Ukraine were retrieved from the database available in the IAEA Power Reactor Information System (PRIS). It is pointed out that there is some uncertainty in evaluating the amount of GHG emissions produced during the LC for different generation technologies, which is stemming from the use of non-harmonized methods for estimating GHG emissions. An approach implying consideration of GHG emissions for the entire LC is believed to be promising for a holistic comparative analysis of different power generation technologies in terms of their influence on the environment and climate. In this connection, developing a unified methodology for assessing GHG emissions and obtaining more precise data on GHG emissions at different LC stages of power plants of different types seem to be a topical issue. The performed comparative analysis of generation technologies in terms of GHG emissions throughout the LC has demonstrated that NPPs are advantageous in this respect over the majority of power generation technologies based on the use of conventional hydrocarbon fuels and renewable sources of energy.

Electricity generation in thermal power plants as the largest producer of electricity in Iran is associated with greenhouse gas emissions. In this paper, using the Malmquist-Luenberger method, green productivity, and efficiency changes are measured for 31 thermal power plants (including 12 steam power plants, 13 gas power plants, and six combined cycle power plants) during 2009-2016. The results show a slight increase in green productivity in gas power plants and a slight reduction in green productivity in combined cycle power plants. Also, green productivity in steam power plants has not changed approximately. The mean values of the Malmquist-Luenberger index for these three types of power plants are 1.007, 0.997, and 1.0005, respectively. Although the environmental performance of gas power plants is slightly better than the two other types of power plants, but the difference of mean values of the Malmquist-Luenberger index for the three types of power plants is small.Furthermore, if we compare the power plants individually, we get different results, the highest and lowest mean values of the Malmquist-Luenberger index (1.06 and 0.982) is for a steam power plant (Shahid Mofateh) and a gas power plant (Konarak) respectively. Therefore, the power generation method and type of power plant (gas, steam and combined cycle) have no significant effect on the environmental performance of power plants and the environmental performance of them can be affected by other factors. The results also show that combined cycle power plants are more efficient than gas power plants.

Livestock are by far the greatest contributor to Australian agricultural greenhouse gas (GHG) emissions and are projected to account for 72% of total agricultural emissions by 2020. This necessitates the development of GHG mitigation strategies from the livestock sector. Currently there are many research streams investigating the efficacy of GHG mitigation technologies, though most are at the individual animal level. Here we examine the effect of a promising animal-scale intervention - increasing ewe fecundity - on GHG emissions at the whole farm scale. This approach accounts for seasonal climatic influences on farm productivity and the dynamic interactions between variables. The study used a biophysical model and was based on real data from a property in south-eastern Australia that currently runs a self-replacing prime lamb enterprise. The breeding flock was a composite cross-bred genotype segregating for the FecB gene (after the 'fecundity Booroola' trait observed in Australian Merinos), with typical lambing rates of 150-200% lambs per ewe. Lambs were born in mid-winter (July) and were weaned and sold at 18 weeks of age at the beginning of summer (December). Livestock continuously grazed pastures of phalaris, cocksfoot and subterranean clover and were supplied with barley grain as supplementary feed in seasons when pasture biomass availability was low. Biophysical variables including pasture phenology and flock dynamics were simulated on a daily time-step using the model GrassGro with historical weather data from 1970 to 2012. Whole farm GHG emissions were computed with GrassGro outputs and methodology from the Australian National Greenhouse Accounts Inventory (DCCEE, 2012). Increasing ewe fecundity from 1.0 lamb per ewe at birth (equivalent to scanning rates at pregnancy of 80% of ewes with single lambs, 17% with twins and 3% empty) to 1.5 (scanning rates of 20% ewes with singles, 51% with twins, 26% with triplets and 3% empty as observed at the property) reduced mean emissions intensity from 9.3 to 7.3 t CO2-equivalents/t animal product and GHG emissions per animal sold by 32%. Increasing fecundity reduced average lamb sale liveweight from 42 to 40 kg, but this was offset by an increase in annual sheep sales from 8 to 12 head/ha and an increase in average annual meat production from 410 to 540 kg liveweight/ha. A key benefit associated with increasing sheep fecundity is the ability to increase enterprise productivity whilst remaining environmentally sustainable. For the same long-term average annual stocking rate as an enterprise running genotypes with lower fecundity, it was shown that genotypes with high fecundity such as those on the property could either increase meat and wool productivity from 449 to 571 kg/ha (clean fleece weight plus liveweight at sale) with little change in net GHG emissions, or reduce net GHG emissions from 4.1 to 3.2 t CO2-equivalents/ha for similar average annual farm productivity. In either case, GHG emissions intensity was reduced by about 2.1 t CO2-equivalents/t animal product. From a methodological perspective, this study revealed that differences in computing the relative effect of increased fecundity on total farm production, GHG emissions or emissions intensity either within or across years were relatively small. For example, the mean difference in emissions intensity of an enterprise obtaining 1.5 lambs per ewe relative to an enterprise obtaining 1.0 lamb per ewe computed within years was -25%, whereas the relative difference in mean emissions intensity across years was -27%. Such findings justify the traditional approach of previous GHG mitigation studies which compare differences (e.g. abatement potential) between values averaged across multiple-year simulation runs, as opposed to the method of computing the differences between intervention strategies within years then comparing the average difference.

Mitigation of greenhouse gas emissions from beef production in western Canada – Evaluation using farm-based life cycle assessment