Supply- and demand-side effects of power sector planning with demand-side management options and SO2 emission constraints

This paper examines the implications of SO₂ emission mitigation constraints in the power sector planning in Indonesia—a developing country—during 2003–2017 from a long term integrated resource planning perspective. A decomposition model is developed to assess the contributions of supply- and demand-side effects to the total changes in CO₂, SO₂ and NO_x emissions from the power sector due to constraints on SO₂ emissions. The results of the study show that both the supply- and demand-side effects would act towards the reduction of CO₂, SO₂ and NO_x emissions. However, the supply-side effect would play the dominant role in emission mitigations from the power sector in Indonesia. The average incremental SO₂ abatement cost would increase from US$ 970 to US$ 1271 per ton of SO₂, while electricity price would increase by 2–18% if the annual SO₂ emission reduction target is increased 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.     

Co-benefits analysis on climate change and environmental effects of wind-power: A case study from Xinjiang,China

The combustion of fossil fuel contributes to not only global warming but also the emissions of air pollutants. In China, the rapid growth of energy consumption leads to a large quantity of greenhouse gas (GHG) and air pollutant emissions. Although many measures have been proposed by the local governments to mitigate the GHG emissions and improve air quality, limited economic resources slow the efforts of the local government to implement measures to control both types of emissions. The co-benefits approach can use resources efficiently to solve multiple environmental problems. In this study, we first calculated the CO₂ and air pollutants (SO₂, NO_x and PM_2.5) emissions in Xinjiang Uygur Autonomous Region. Then, the co-benefits of wind power, including mitigation of CO₂ and air pollutants (SO₂, NO_x and PM_2.5) emissions and water savings, were assessed and quantified in the Xinjiang Uygur Autonomous Region. The results demonstrate that, during the 11th five-year period (2006–2010), emissions mitigation by wind power accounted for 4.88% (1065 × 10⁴ t) of CO₂, 4.31% (4.38 × 10⁴ t) of SO₂, 8.23% (3.41 × 10⁴ t) of NO_x and 4.23% (0.32 × 10⁴ t) of PM_2.5 emission by the thermal power sector. The total economic co-benefits of wind power accounted for 0.46% (1.38 billion 2009US$) of the GDP of Xinjiang during 2006–2010.     

Estimating co-pollutant benefits from climate change policies in the electricity sector: A regression approach

We use data from US power plants and a regression based approach to empirically estimate the marginal rate of co-pollutant emission reductions resulting from a mass-based carbon reduction policy for electricity producers. The standard approach to estimating co-pollutant reductions uses Linear Programming Models. These models require millions of input variables and constraints, resulting in long computational times and an opaque simulation process, while yielding only point estimates for key variables of interest. Our regression-based approach has far fewer data requirements, needs less computational resources, and produces estimates with confidence intervals that capture estimation uncertainty. Moreover, it is straightforward and transparent to implement and provides a larger range of potential outcomes for policy makers to consider. Our results indicate that a 1% decrease in electricity output from coal (gas) power plants would reduce SO₂ by 0.6% and NO_x by 0.8% (0.7%). These are not statistically significant different than estimates reported by the Environmental Protection Agency (EPA). We estimate that reducing electricity output enough to reduce CO₂ emissions by one ton yields health benefits of $15.33 from NO_x reductions and $59.64 from SO₂ reductions.     

Experimental determination and analysis of CO2, SO2 and NOx emission factors in Iran’s thermal power plants

Emission factors of CO₂, SO₂ and NO_x emitted from Iran’s thermal power plants are fully covered in this paper. To start with, emission factors of flue gases were calculated for fifty thermal power plants with the total installed capacity of 34,863 MW over the period 2007–2008 with regard to the power plants’ operation characteristics including generation capacity, fuel type and amount and the corresponding alterations, stack specifications, analysis of flue gases and physical details of combustion gases in terms of g kWh⁻¹. This factor was calculated as 620, 2.57 and 2.31 g kWh⁻¹ for CO₂, SO₂ and NO_x respectively. Regarding these results, total emissions of CO₂, SO₂ and NO_x were found to be 125.34, 0.552 and 0.465 Tg in turn. To achieve an accurate comparison, these values were compared with their alternatives in North American countries. According to this comparison, emission factor of flue gases emitted from Iran’s thermal power plants will experience an intensive decline if renewable, hydroelectric and nuclear types of energy are more used, power plants’ efficiency is increased and continuous emission monitoring systems and power plant pollution reduction systems are utilized.     

Estimate of ecological efficiency for thermal power plants in Brazil

Global warming and the consequent climatic changes that will come as a result of the increase of CO₂ concentration in the atmosphere have increased the world’s concern regarding reduction of these emissions, mainly in developed countries that pollute the most. Electricity generation in thermal power plants, as well as other industrial activities, such as chemical and petrochemical ones, entail the emission of pollutants that are harmful to humans, animals and plants. The emissions of carbon oxides (CO and CO₂) and nitrous oxide (N₂O) are directly related to the greenhouse effect. The negative effects of sulfur oxides (SO₂ and SO₃ named SO_x) and nitrogen oxides (NO_x) are their contribution to the formation of acid rain and their impacts on human health and on the biota in general. This study intends to evaluate the environmental impacts of the atmospheric pollution resulting from the burning of fossil fuels. This study considers the emissions of CO₂, SO_x, NO_x and PM in an integral way, and they are compared to the international air quality standards that are in force using a parameter called ecological efficiency (ε).     

Trade-off in emissions of acid gas pollutants and of carbon dioxide in fossil fuel power plants with carbon capture

This paper investigates the impact of capture of carbon dioxide (CO₂) from fossil fuel power plants on the emissions of nitrogen oxides (NO_X) and sulphur oxides (SO_X), which are acid gas pollutants. This was done by estimating the emissions of these chemical compounds from natural gas combined cycle and pulverized coal plants, equipped with post-combustion carbon capture technology for the removal of CO₂ from their flue gases, and comparing them with the emissions of similar plants without CO₂ capture. The capture of CO₂ is not likely to increase the emissions of acid gas pollutants from individual power plants; on the contrary, some NO_X and SO_X will also be removed during the capture of CO₂. The large-scale implementation of carbon capture is however likely to increase the emission levels of NO_X from the power sector due to the reduced efficiency of power plants equipped with capture technologies. Furthermore, SO_X emissions from coal plants should be decreased to avoid significant losses of the chemicals that are used to capture CO₂. The increase in the quantity of NO_X emissions will be however low, estimated at 5% for the natural gas power plant park and 24% for the coal plants, while the emissions of SO_X from coal fired plants will be reduced by as much as 99% when at least 80% of the CO₂ generated will be captured.     

Co-benefits of CO2 emission reduction in a developing country

In this paper, we examine the co-benefits of reducing CO₂ emissions in Thailand during 2005–2050 in terms of local pollutant emissions as well as the role of renewable-, biomass- and nuclear-energy. It also examines the implications of CO₂ emission reduction policy on energy security of the country. The analyses are based on a long term energy system model of Thailand using the MARKAL framework. The study shows that the power sector would account for the largest share (over 60%) in total CO₂ emission reduction followed by the industrial and transport sectors. Under the CO₂ emission reduction target of 30%, there would be a reduction in SO₂ emission by 43% from the base case level. With the CO₂ emission reduction target of 10–30%, the cumulative net energy imports in the country during 2005–2050 would be reduced in the range of over 16 thousand PJ to 26 thousand PJ from the base case emission level. Under the CO₂ emission reduction targets, the primary energy supply system would be diversified towards lower use of coal and higher use of natural gas, biomass and nuclear fuels.     

Does a regional greenhouse gas policy make sense? A case study of carbon leakage and emissions spillover

The Regional Greenhouse Gas Initiative (RGGI) is a state-level effort by ten northeast states in the U.S. to control CO₂ emissions from the electric sector. The approach adopted by RGGI is a regional cap-and-trade program, which sets a maximal annual amount of regional CO₂ emissions that can be emitted from the electric sector. However, incoherence of the geographic scope of the regional electricity market is expected to produce two undesirable consequences: CO₂ leakage and NO_x and SO₂ emissions spillover. This paper addresses these two issues using transmission-constrained electricity market models. The results show that although larger CO₂ leakage is associated with higher allowance prices, it is negatively related to CO₂ prices if measured in percentage terms. On the other hand, SO₂ and NO_x emissions spillover increase in commensurate with CO₂ allowance prices. Demand elasticity attenuates the effect of emissions trading on leakage and emissions spillover. This highlights the difficulties of designing a regional or local climate policy.     

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.     

Internalisation of external cost in the power generation sector: Analysis with Global Multi-regional MARKAL model

The Global MARKAL-Model (GMM), a multi-regional “bottom-up” partial equilibrium model of the global energy system with endogenous technological learning, is used to address impacts of internalisation of external costs from power production. This modelling approach imposes additional charges on electricity generation, which reflect the costs of environmental and health damages from local pollutants (SO₂, NO_x) and climate change, wastes, occupational health, risk of accidents, noise and other burdens. Technologies allowing abatement of pollutants emitted from power plants are rapidly introduced into the energy system, for example, desulphurisation, NO_x removal, and CO₂ scrubbers. The modelling results indicate substantial changes in the electricity production system in favour of natural gas combined cycle, nuclear power and renewables induced by internalisation of external costs and also efficiency loss due to the use of scrubbers. Structural changes and fuel switching in the electricity sector result in significant reduction of emissions of both local pollution and CO₂ over the modelled time period. Strong decarbonisation impact of internalising local externalities suggests that ancillary benefits can be expected from policies directly addressing other issues then CO₂ mitigation. Finally, the detailed analysis of the total generation cost of different technologies points out that inclusion of external cost in the price of electricity increases competitiveness of non-fossil generation sources and fossil power plants with emission control.     

Environmental impacts and benefits of regional power grid interconnections for China

This paper describes the development of China's power industry, present situation, environmental influences and potential benefits of regional power grid interconnections in China. Power plants in China are mainly thermal, burning fossil fuels especially coal which emit a great deal of pollutants and greenhouse gases such as SO₂, NO_x and CO₂. China leads all other countries in emissions of SO₂, CO₂, and the power industry is the largest contributor to these emissions. There are a number of environmental benefits through regional power grid interconnection. That is, the construction of small electricity generation capacity would be avoided; natural resources would be used to generate electricity on a regional scale; and generating sources can be separated from centers of electricity use, which will decrease emission of pollutants and greenhouse gases and help to reduce human exposure to elevated air pollutant concentrations. Therefore, gradually enlarged power grids, and power grid interconnection, should be part of the general pattern of power system development in China.     

Potential emissions reductions from grandfathered coal power plants in the United States

A two-tiered approach to environmental regulation in the United States has long allowed existing coal-fired power plants to emit air pollutants at far higher rates than new facilities. The potential for reducing the emissions of existing coal-fired facilities is quantified via two hypothetical scenarios: the installation of available retrofit control technologies, or the imposition of New Source Performance Standards (NSPS). Available control technologies could have reduced year 2005 emissions by 56% for NO_x and 72% for SO₂ for a cost of $11.3 billion/year (2004$), likely yielding far larger benefits to human health. Slightly more emission reductions would be achieved by upgrading or replacing existing facilities to achieve the NSPS emissions limits required of all new facilities. Potential CO₂ reductions are more speculative due to the emerging nature of carbon capture and efficiency retrofit technologies. Recent policies such as the Cross-State Air Pollution Rule would likely achieve most of the NO_x and SO₂ reduction potential identified by the scenario analyses for grandfathered facilities. However, escalating obstacles to new generation capacity may perpetuate the reliance on an aging fleet of power plants, resulting in higher rates of coal consumption and CO₂ emissions than could be achieved by new or retrofit units.     

Spatial variation of emissions impacts due to renewable energy siting decisions in the Western U.S. under high-renewable penetration scenarios

One of the policy goals motivating programs to increase renewable energy investment is that renewable electric generation will help reduce emissions of CO₂ as well as emissions of conventional pollutants (e.g., SO₂ and NO_x). As a policy instrument, Renewable Portfolio Standards (RPS) encourage investments in wind, solar and other generation sources with the goal of reducing air emissions from electricity production. Increased electricity production from wind turbines is expected to displace electricity production from fossil-fired plants, thus reducing overall system emissions. We analyze the emissions impacts of incremental investments in utility-scale wind power, on the order of 1 GW beyond RPS goals, in the Western United States using a utility-scale generation dispatch model that incorporates the impacts of transmission constraints. We find that wind investment in some locations leads to slight increases in overall emissions of CO₂, SO₂ and NO_x. The location of wind farms influences the environmental impact by changing the utilization of transmission assets, which affects the overall utilization of power generation sources and thus system-level emissions. Our results suggest that renewable energy policy beyond RPS targets should be carefully crafted to ensure consistency with environmental goals.     

Ecological efficiency in CHP: Biodiesel case

This paper evaluates and quantifies the environmental impact resulting from the combination of biodiesel fuel (pure or blended with diesel), and diesel combustion in thermoelectric power plants that utilize combined cycle technology (CC). In regions without natural gas, the option was to utilize diesel fuel; the consequence would be a greater emission of pollutants. Biodiesel is a renewable fuel which has been considerably interesting in Brazil power matrix in recent years. The concept of ecological efficiency, largely evaluates the environmental impact caused by CO₂, SO₂, NO_x and particle matter (PM) emissions. The pollution resulting from biodiesel and diesel combustion is analyzed, separately considering CO₂, SO₂, NO_x and particulate matter gas emissions, and comparing them international standards currently used regarding air quality. It can be concluded that it is possible to calculate the qualitative environmental factor, and the ecological effect, from a thermoelectric power plant utilizing central heat power (CHP) of combined cycle. The ecological efficiency for pure biodiesel fuel (B100) is 98.16%; for biodiesel blended with conventional diesel fuel, B20 (20% biodiesel and 80% diesel) is 93.19%. Finally, ecological efficiency for conventional diesel is 92.18%, as long as a thermal efficiency of 55% for thermoelectric power plants occurs.     

Reduction of greenhouse gas emission on a medium-pressure boiler using hydrogen-rich fuel control

The increasing emission of greenhouse gases from the combustion of fossil fuel is believed to be responsible for global warming. A study was carried out to probe the influence of replacing fuel gas with hydrogen-rich refinery gas (R.G.) on the reduction of gas emission (CO₂ and NO_x) and energy saving. Test results show that the emission of CO₂ can be reduced by 16.4% annually (or 21,500 tons per year). The NO_x emission can be 8.2% lower, or 75 tons less per year. Furthermore, the use of refinery gas leads to a saving of NT$57 million (approximately US$1.73 million) on fuel costs each year. There are no CO₂, CO, SO_x, unburned hydrocarbon, or particles generated from the combustion of added hydrogen. The hydrogen content in R.G. employed in this study was between 50 and 80 mol%, so the C/H ratio of the feeding fuel was reduced. Therefore, the use of hydrogen-rich fuel has practical benefits for both energy saving and the reduction of greenhouse gas emission.     

Demonstration of the environmental and demand-side management benefits of grid-connected photovoltaic power systems

This study investigated the pollutant emission reduction and demand-side management potential of 16 photovoltaic (PV) systems installed across the US during 1993 and 1994. The US Environmental Protection Agency (EPA) and 11 electric power companies sponsored the project. This article presents results of analyses of each PV system's ability to offset power plant emissions of sulfur dioxide (SO₂), nitrogen oxides (NO_x), carbon dioxide (CO₂) and particulates and to provide power during peak demand hours for the individual host buildings and peak load hours for the utility. The analyses indicate a very broad range in the systems' abilities to offset pollutant emissions, due to variation in the solar resource available and the emission rates of the participating utilities' load following generation plants. Each system's ability to reduce building peak demand was dependent on the correlation of that load to the available solar resource. Most systems operated in excess of 50% of their capacity during building peak load hours in the summer months, but well below that level during winter peak hours. Similarly, many systems operated above 50% of their capacity during utility peak load hours in the summer months, but at a very low level during winter peak hours.     

Transmission network-based energy and environmental assessment of plug-in hybrid electric vehicles

The introduction of plug-in hybrid electric vehicles (PHEVs) is expected to have a significant impact on regional power systems and pollutant emissions. This paper analyzes the effects of various penetrations of PHEVs on the marginal fuel dispatch of coal, natural gas and oil, and on pollutant emissions of CO₂, NO_x, SO₂ in the New York Metropolitan Area for two battery charging scenarios in a typical summer and winter day. A model of the AC transmission network of the Northeast Power Coordinating Council (NPCC) region with 693 generators is used to realistically incorporate network constraints into an economic dispatch model. A data-based transportation model of approximately 1 million commuters in NYMA is used to determine battery charging pattern. Results show that for all penetrations of PHEVs network-constrained economic dispatch of generation is significantly more realistic than unconstrained cases. Coal, natural gas and oil units are on the margin in the winter, and only natural gas and oil units are on the margin in the summer. Hourly changes in emissions from transportation and power production are dominated by vehicular activity with significant overall emissions reductions for CO₂ and NO_x, and a slight increase for SO₂. Nighttime regulated charging produces less overall emissions than unregulated charging from when vehicles arrive home for the summer and vice versa for the winter. As PHEVs are poised to link the power and transportation sectors, data-based models combining network constraints and economic dispatch have been shown to improve understanding and facilitate control of this link.     

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.     

Economic potential of renewable energy in Vietnam's power sector

A bottom-up Integrated Resource Planning model is used to examine the economic potential of renewable energy in Vietnam's power sector. In a baseline scenario without renewables, coal provides 44% of electricity generated from 2010 to 2030. The use of renewables could reduce that figure to 39%, as well as decrease the sector's cumulative emission of CO₂ by 8%, SO₂ by 3%, and NO_x by 4%. In addition, renewables could avoid installing 4.4 GW in fossil fuel generating capacity, conserve domestic coal, decrease coal and gases imports, improving energy independence and security. Wind could become cost-competitive assuming high but plausible on fossil fuel prices, if the cost of the technology falls to 900 US$/kW.