Analysis of emission taxes levying on regional electric power structure adjustment with an inexact optimization model - A case study of Zibo,China

In this study, an inexact two-stage chance-constrained programming (ITSCCP) model was provided for multiple electrical power system supply and demand management in Zibo City under uncertainties. Three scenarios about the electric power structure adjustment, renewable power generation, and the emission taxes were designed. Methods of two-stage stochastic programming (TSP) and inexact chance-constrained programming (ICCP) were incorporated into the developed model to tackle uncertainties in terms of various cost coefficients, decision maker's risk attitude which was described by interval values and probability distributions. Moreover, under the objective of cost minimize, the electrical power generation planning for each terms under different feasibility degrees (violating constraints or available resources situations) can be obtained. The results indicated that higher probability of violating system constraints would increase risk of system, but lower the total cost; the proportion of optimized thermal power generation and imported electricity would decrease, which could promote the energy conservation and emissions reduction in some degree. At the same time, the model results are valuable for decision-makers to tackle the uncertainty of the power generation schemes within a complicated energy system and make a desired compromise between the satisfaction degree of the economic benefits and feasibility degree of constraints.     

Frontiers in combustion techniques and burner designs for emissions control and CO2 capture: A review

The use of fossil fuel is expected to increase significantly by midcentury because of the large rise in the world energy demand despite the effective integration of renewable energies in the energy production sector. This increase, alongside with the development of stricter emission regulations, forced the manufacturers of combustion systems, especially gas turbines, to develop novel combustion techniques for the control of NO_x and CO₂ emissions, the latter being a greenhouse gas responsible for more than 60% to the global warming problem. The present review addresses different burner designs and combustion techniques for clean power production in gas turbines. Combustion and emission characteristics, flame instabilities, and solution techniques are presented, such as lean premixed air‐fuel (LPM) and premixed oxy‐fuel combustion techniques, and the combustor performance is compared for both cases. The fuel flexibility approach is also reviewed, as one of the combustion techniques for controlling emissions and reducing flame instabilities, focusing on the hydrogen‐enrichment and the integrated fuel‐flexible premixed oxy‐combustion approaches. State‐of‐the‐art burner designs for gas turbine combustion applications are reviewed in this study, including stagnation point reverse flow (SPRF) burner, dry low NO_x (DLN) and dry low‐emission (DLE) burners, EnVironmental burners (including EV, AEV, and SEV burners), perforated plate (PP) burner, and micromixer (MM) burner. Special emphasis is made on the MM combustor technology, as one of the most recent advances in gas turbines for stable premixed flame operation with wide turndown and effective control of NO_x emissions. Since the generation of pure oxygen is prerequisite to oxy‐combustion, oxygen‐separation membranes became of immense importance either for air separation for clean oxy‐combustion applications or for conversion/splitting of the effluent CO₂ into useful chemical and energy products. The different carbon‐capture technologies, along with the most recent carbon‐utilization approaches towards CO₂ emissions control, are also reviewed.     

Climate change mitigation with integration of renewable energy resources in the electricity grid of New South Wales,Australia

The implementation of climate change mitigation strategies may significantly affect the current practices for electricity network operation. Increasing penetration of renewable energy generation technologies into electricity networks is one of the key mitigation strategies to achieve greenhouse gas emission reduction targets. Additional climate change mitigation strategies can also contribute to emission reduction thereby supplementing the renewable energy generation participation, which may be limited due to technical constraints of the network. In this paper, the penetration requirements for different renewable energy generation resources are assessed while concurrently examining other mitigation strategies to reduce overall emissions from electricity networks and meet requisite targets. The impacts of climate change mitigation strategies on the demand and generation mix are considered for facilitating the penetration of renewable generation. New climate change mitigation indices namely change in average demand, change in peak demand, generation flexibility and generation mix have been proposed to measure the level of emission reduction by incorporating different mitigation strategies. The marginal emissions associated with the individual generation technologies in the state of New South Wales (NSW) are modelled and the total emissions associated with the electricity grid of NSW are evaluated.     

Feasibility and flexibility for a trigeneration system

Trigeneration system, which produces heat, cold and electricity simultaneously, is generally designed based on the nominal condition. However, the utility demands are seldom fixed and they are usually changing in periodical manner with the climate and the human activities. These demand changes make the system design difficult. To ensure operability, the system should be feasible and flexible to tackle such demand variations. Over-sizing, thermal storage and flexibility re-allocation can be used to improve a trigeneration system's feasibility and flexibility. These techniques may enlarge the feasible operating region, change and shift the expected utility production demands and interchange between different generation capabilities according to the demand requirements. As a result, the process feasibility and flexibility can be improved. With feasible operation ensured, process flexibility can be considered under economic trade-offs. A flexible design with reasonable investment and operating costs provides additional benefits to cater demand changes in the future. In this study, process flexibility and feasibility characteristics are proposed and evaluated from a new perspective. These are demonstrated in the trigeneration system design with a pre-defined structure to handle periodical utility demand deviations in a commercial building complex.     

Steam-gas power stations with multi-stage residual-oil combustion

This paper describes a method for the multi-stage combustion of high-sulphur residual fuel oils in thermal power stations which ensures minimum contamination of the atmosphere. In the first stage of combustion, high-pressure steam and fuel gas are produced. The latter is cooled and freed of ash and sulphur compounds. The steam and the purified gas are then used for power generation. The method gives a high rate of sulphur removal and considerable reduction of nitrogen oxide emission. This new power station concept employs gas turbines and steam/gas turbines to achieve the optimal use of energy. A discussion of technical and economic aspects concludes the paper.     

A review of inlet air-cooling technologies for enhancing the performance of combustion turbines in Saudi Arabia

Peak demand for electric power in Saudi Arabia occurs during the middle of the day in summer and is almost double the off-peak demand. The demand profile is ill-matched to the performance profile of combustion turbines as their power output decreases with increased inlet-air temperature. Approximately 42% of the Saudi Electric Company’s (SEC) annual energy sales are generated by combustion turbines, yet the turbines experience a 24% decrease in system capacity during the summer due to ambient air temperatures up to 50 °C. Methods of increasing the energy contribution of existing plant by changing their performance profiles through inlet air cooling could make a substantial contribution to the additional 35 GW in peak demand capacity required by 2023. An extensive review of the various combustion turbine inlet cooling technology (CTIAC) options open to SEC has been made, and their key benefits and drawbacks in relation to the environmental conditions and generational requirements of Saudi Arabia have been identified.     

Simultaneous planning of plug-in hybrid electric vehicle charging stations and wind power generation in distribution networks considering uncertainties

Recently, plug-in hybrid electric vehicles (PHEV) are becoming more attractive than internal combustion engine vehicles (ICEV). Hence, design and modeling of charging stations (CSs) has vital importance in distribution system level. In this paper, a new formulation for PHEV charging stations is presented with the strategic presence of wind power generation (WPG). This study considers constraints of the system losses, the regulatory voltage limits, and the charge/discharge schedule of PHEV based on the social behavior of drivers for appropriate placement of PHEV charging stations in electricity grid. The role of CSs and WPG units must be correctly assessed to optimize the investment and operation cost for the whole system. However, the wind generation owners (WGOs) have different objective functions which might be contrary to the objectives of distribution system manager (DSM). It is assumed that aggregating and management of charge/discharge program of PHEVs are smartly carried out by DSM. This paper presents a long-term bi-objective model for optimal planning of PHEV charging stations and WPG units in distribution systems which simultaneously optimize two objectives, namely the benefits of DSM and WGO. It also considers the uncertainty of load growth, electricity price and PHEV access to the charging station using Mont-Carlo simulation (MCS) method. Initial state of charge uncertainty is also modeled based on scenario approach in PHEV batteries and wind turbine power generation using weibull distribution. Non dominated sorting genetic algorithm (NSGA-II) is used to solve the optimization problem. The simulation has been conducted on the nine-bus system.     

Emissions from distributed vs. centralized generation: The importance of system performance

Distributed generation (DG) offers a number of potential benefits, but questions remain about environmental performance. Air emissions from five key DG technologies; gas engines, diesel engines, gas turbines, micro-turbines, and fuel cells, were systematically compared with total energy supply systems based on centralized gas turbines (CCGT) and coal steam turbines plus distributed heating (DH) using gas-fired boilers. Based on emissions and operational factors from existing commercially marketed DG-CHP technologies, combined heat and power (CHP) applications are considered, which are remotely monitored and operated as base-load supply. Emissions results are characterized using heat-to-power ratios (HPRs), which concisely describe different types of energy demand under different applications or seasonal conditions. At an HPR of zero (i.e. the special case of electricity-only), CCGT with DH gives the lowest emissions portfolio, but at HPR values typical for buildings in the United States, efficiency advantages ensure gas-fired combustion DG-CHP technologies become broadly competitive across the range of key emissions. Fuel cell DG-CHP provides a very low emissions portfolio, but at a significant cost premium. At higher HPR values, emissions from heat supply can become a key issue, leading to the surprising finding that some combustion-based DG-CHP systems have lower total emissions than fuel cell-based systems. Based on these insights, the paper concludes with a discussion of streamlined yet rigorous regulatory approaches for DG-CHP technologies.     

Significance of CO2-free hydrogen globally and for Japan using a long-term global energy system analysis

In this paper, the significance of CO₂-free hydrogen is discussed using a long-term global energy system. The energy demand–supply system including CO₂-free hydrogen was assumed, though there are still large uncertainties as to whether a global CO₂-free hydrogen energy system will be deployed. System analysis was conducted using the global and long-term intertemporal optimization energy model GRAPE under severe CO₂ emission constraints. Applied global CO₂ constraints for 2050 were a 50% reduction from 1990 levels. CO₂ constraints accounting for Intended Nationally Determined Contributions (INDCs) in each region were also considered. A variety of energy resources and technologies were considered in this model. Hydrogen can be produced from low-grade coal or natural gas with CO₂ capture and electricity from renewable energy. The hydrogen CIF (cost, insurance, and freight) price for Japan was about 3.2 cents/MJ in 2030. Hydrogen demand technologies considered in this paper are hydrogen-fired power plants, direct combustion, combined heat and power (fuel cells, gas engines, and gas turbines), fuel cell vehicles, and hydrogen internal combustion engine vehicles. The majority of CO₂-free hydrogen was deployed in the transportation sector. CO₂-free hydrogen was utilized in the power sector, where deployment of other zero emission technology has some constraints. From an economic viewpoint, CO₂-free hydrogen can reduce the global energy system cost. From the viewpoint of a localized region, such as Japan, deployment of CO₂-free hydrogen can improve energy security and environmental indicators.     

Combustion technology developments in power generation in response to environmental challenges

Combustion system development in power generation is discussed ranging from the pre-environmental era in which the objectives were complete combustion with a minimum of excess air and the capability of scale up to increased boiler unit performances, through the environmental era (1970–), in which reduction of combustion generated pollution was gaining increasing importance, to the present and near future in which a combination of clean combustion and high thermodynamic efficiency is considered to be necessary to satisfy demands for CO₂ emissions mitigation.

From the 1970s on, attention has increasingly turned towards emission control technologies for the reduction of oxides of nitrogen and sulfur, the so-called acid rain precursors. By a better understanding of the NO_x formation and destruction mechanisms in flames, it has become possible to reduce significantly their emissions via combustion process modifications, e.g. by maintaining sequentially fuel-rich and fuel-lean combustion zones in a burner flame or in the combustion chamber, or by injecting a hydrocarbon rich fuel into the NO_x bearing combustion products of a primary fuel such as coal.

Sulfur capture in the combustion process proved to be more difficult because calcium sulfate, the reaction product of SO₂ and additive lime, is unstable at the high temperature of pulverized coal combustion. It is possible to retain sulfur by the application of fluidized combustion in which coal burns at much reduced combustion temperatures. Fluidized bed combustion is, however, primarily intended for the utilization of low grade, low volatile coals in smaller capacity units, which leaves the task of sulfur capture for the majority of coal fired boilers to flue gas desulfurization.

During the last decade, several new factors emerged which influenced the development of combustion for power generation. CO₂ emission control is gaining increasing acceptance as a result of the international greenhouse gas debate. This is adding the task of raising the thermodynamic efficiency of the power generating cycle to the existing demands for reduced pollutant emission. Reassessments of the long-term availability of natural gas, and the development of low NO_x and highly efficient gas turbine–steam combined cycles made this mode of power generation greatly attractive also for base load operation.

However, the real prize and challenge of power generation R&D remains to be the development of highly efficient and clean coal-fired systems. The most promising of these include pulverized coal combustion in a supercritical steam boiler, pressurized fluid bed combustion without or with topping combustion, air heater gas turbine-steam combined cycle, and integrated gasification combined cycle. In the longer term, catalytic combustion in gas turbines and coal gasification-fuel cell systems hold out promise for even lower emissions and higher thermodynamic cycle efficiency. The present state of these advanced power-generating cycles together with their potential for application in the near future is discussed, and the key role of combustion science and technology as a guide in their continuing development highlighted.     

Economic profitability analysis of demand side management program

This study considers both the internal and external costs of the utility in deriving the avoided capacity cost (ACC) and avoided operating cost (AOC) induced in an electric utility caused by the implementation of a demand side management program (DSM). In calculating the ACC, a multiple objective linear programming model is developed. Meanwhile, the AOC is calculated by considering the differences between the total and specific time period energy consumption ratios before and after the implementation of the DSM program. This study also develops an economic analysis method using Net Present Value and Pay Back Year models to assess the economic profitability of implementing a DSM program from a participant’s point of view. The design and construction of a partial load leveling eutectic salt Cooling Energy Storage (CES) air conditioning system in a target office building in Kaohsiung, Taiwan, is discussed in order to simulate the cost benefit of the CES system from the perspective of the utility and from that of the participant. The results confirm the effectiveness of the developed models in simulating the economic benefits of implementing a DSM program from the perspectives of both the utility and the participant.     

A total fuel cycle approach to reducing greenhouse gas emissions: Solar generation technologies as greenhouse gas offsets in U.S. utility systems

Greenhouse gas emissions in the electric utility sector occur not only at generation facilities, but also during upstream processes that support the construction and operation of energy facilities. A total fuel cycle approach is used to evaluate the potential greenhouse gas savings that could result from the deployment of solar generation technologies in utility systems in the United States. Total fuel cycle analyses were completed for several renewable and conventional generation technologies to estimate the total greenhouse gas emission contribution from each generation technology. These results are used to develop total fuel cycle emission rates for planned electric capacity additions in the U.S., and these rates are compared with the emission rates that would occur if solar technologies were substituted for fossil generation capacity additions. Current projections for solar technology deployment are low relative to total capacity additions. Hence, even doubling the planned additions of solar technologies produces less than a 1% reduction in annual CO₂ and CH₄ emissions from new generation. However, the total lifetime greenhouse gas savings from increased deployment of solar technologies can be substantial. Increasing planned solar deployment by only 25% up to the year 2010 can create up to six million tons of CO₂ savings over the lifetime of the solar installations.     

Strategic real option and flexibility analysis for nuclear power plants considering uncertainty in electricity demand and public acceptance

Nuclear power is an important energy source especially in consideration of CO₂ emissions and global warming. Deploying nuclear power plants, however, may be challenging when uncertainty in long-term electricity demand and more importantly public acceptance are considered. This is true especially for emerging economies (e.g., India, China) concerned with reducing their carbon footprint in the context of growing economic development, while accommodating a growing population and significantly changing demographics, as well as recent events that may affect the public's perception of nuclear technology. In the aftermath of the Fukushima Daiichi disaster, public acceptance has come to play a central role in continued operations and deployment of new nuclear power systems worldwide. In countries seeing important long-term demographic changes, it may be difficult to determine the future capacity needed, when and where to deploy it over time, and in the most economic manner. Existing studies on capacity deployment typically do not consider such uncertainty drivers in long-term capacity deployment analyses (e.g., + 40 years). To address these issues, this paper introduces a novel approach to nuclear power systems design and capacity deployment under uncertainty that exploits the idea of strategic flexibility and managerial decision rules. The approach enables dealing more pro-actively with uncertainty and helps identify the most economic deployment paths for new nuclear capacity deployment over multiple sites. One novelty of the study lies in the explicit recognition of public acceptance as an important uncertainty driver affecting economic performance, along with long-term electricity demand. Another novelty is in how the concept of flexibility is exploited to deal with uncertainty and improve expected lifecycle performance (e.g. cost). New design and deployment strategies are developed and analyzed through a multistage stochastic programming framework where decision rules are represented as non-anticipative constraints. This approach provides a new way to devise and analyze adaptation strategies in view of long-term uncertainty fluctuations that is more intuitive and readily usable by system operators than typical solutions obtained from standard real options analysis techniques, which are typically used to analyze flexibility in large-scale, irreversible investment projects. The study considers three flexibility strategies subject to uncertainty in electricity demand and public acceptance: 1) phasing (or staging) capacity deployment over time and space, 2) on-site capacity expansion, and 3) life extension. Numerical analysis shows that flexible designs perform better than rigid optimal design deployment strategies, and the most flexible design combining the above strategies outperforms both more rigid and less flexible design alternatives. It is also demonstrated that a flexible design benefits from the strategies of phasing and capacity expansion most significantly across all three strategies studied. The results provide useful insights for policy and decision-making in countries that are considering new nuclear facility deployment, in light of ongoing challenges surrounding new nuclear builds worldwide.     

The cost of uncertainty in capacity expansion problems

The goals of this paper are to present a two‐stage programming model for the capacity expansion problem under uncertainty of demand and explore the impact of this uncertainty on cost. The model is a mixed integer nonlinear programming (MINLP) model with the consideration of uncertainty used to maximize the expected present value of utility profits over the planning horizon, under the constraints of rate of return and reserve margin regulation. The results reveal that the uncertainty harms the profit seriously. In this paper both microeconomics and mathematical programming are used to analyse the problem. We try to observe the economic behaviour of the utility with uncertainty involved. We also investigate the influence on the cost of uncertainty of each economic parameter. Copyright © 1999 John Wiley & Sons, Ltd.     

Greenhouse gas emission mitigation in the Sri Lanka power sector supply side and demand side options

Sri Lanka has had a hydropower dominated electricity generation sector for many years with a gradually decreasing percentage contribution from hydroresources. At the same time, the thermal generation share has been increasing over the years. Therefore, the expected fuel mix in the future in the large scale thermal generation system would be dominated by petroleum products and coal. This will result in a gradual increase in greenhouse gas (GHG) and other environmental emissions in the power sector and, hence, require special attention to possible mitigation measures.

This paper analyses both the supply side and demand side (DSM) options available in the Sri Lanka power sector in mitigating emissions in the sector considering the technical feasibility and potential of such options. Further, the paper examines the carbon abatement costs associated with such supply side and DSM interventions using an integrated resource planning model, which is not used in Sri Lanka at present. The sensitivities of the final generation costs and emissions to different input parameters, such as discount rates, fuel prices and capital costs, are also presented in the paper. It is concluded that while some DSM measures are economically attractive as mitigation measures, all the supply side options have a relatively high cost of mitigation, particularly in the context of GHG emission mitigation. Further it is observed that when compared with the projected price of carbon under different global carbon trading scenarios, these supply side options cannot provide economically beneficial CO₂ mitigation in countries like Sri Lanka.     

A review on the pattern of electricity generation and emission in Indonesia from 1987 to 2009

The level of energy demand plays a fundamental role in today's society. It is a vital input in supporting the physical and social development of a country, as well as national economic growth. Looking at the energy demand scenario in present time, the global energy consumption is likely to grow faster than the population growth across the world. Like any other energy sectors, electricity demand has significantly increased in Indonesia over the past years. Currently, there are six types of power plants in the country. The main sources of electrical energy are generated using the gas turbines, steam turbines, combined cycles, geothermal, diesel engine and hydro-powers. Most of Indonesia's power plants are using fossil fuel for electricity generation. Substantial growth in domestic energy demand, however, would be a major challenge for Indonesia's energy supply sector in the future. Over the past decade, thermal power plants generated about 86.69% of electricity and about 13.31% was generated by renewable energy such as hydro-power and geothermal in 2009. The purpose of this study is to chronicle and show a clear view of 23 years trend of Indonesia's electricity generation industry. Furthermore, the capacity of power generation installed and electricity generation from 1987 to 2009 has been gathered for this study. The total pollutant emissions and emission per unit electricity generation for each type of power plants have been also calculated using emission factors. Also, the pattern of electricity generation and emission has been presented. The results show that the implementation and contribution of combined cycle power plants should be increased together with renewable energy and natural gas which are recommended to reduce greenhouse gas emission.     

Conceptual design of compressed air energy storage electric power systems

Conceptual design studies have been conducted to identify Compressed Air Energy Storage (CAES) systems which are technically feasible and potentially attractive for future electric utility load-levelling applications. The CAES concept consists of compressing air during off-peak periods and storing it in underground facilities for later use. During peak-load periods the air would be withdrawn, heated by recuperation and combustion and expanded through turbines to generate power. By using off-peak electricity for compression and stored air for peak-load generation, the resulting oil consumption would be about 40 per cent of that consumed by conventional gas-turbine peaking plants. The turbomachinery requirements for this type of system could be met using existing equipment with relatively modest modifications. Although the study discussed herein focused on the storage of air in hydraulically compensated, mined, hard-rock caverns, the compressed air could also be stored in underground aquifers or leached-out salt cavities. Conventional underground excavation technology could be used to construct these storage caverns. A geological survey of the north-central and north-east regions of the United States indicated that sufficient siting opportunities exist such that a prudently designed CAES plant should have little long-term adverse impact on the environment. The competitive position of CAES relative to conventional generation alternatives is highly dependent on utility-specific factors. The cost of electric energy from CAES is generally competitive with costs from conventional peak-shaving systems such as gas turbines and will improve as low-cost off-peak energy from nuclear plants becomes available.     

Catalytically stabilized combustion

This paper has reviewed the background leading up to the development of the catalytic combustor, selected results of experimental studies, developments in modelling techniques, and some aspects of applications to gas turbines and furnaces. The future prospects of the technology are exciting. The design of catalytic combustors for gas turbines is underway. In fact, at least one U.S. manufacturer is believed to have a catalytic gas turbine ready for introduction in the near future. Retrofit designs for stationary gas turbines and for furnaces could be implemented readily. Significant economic benefits could stem from such applications. In addition, the demonstration that the catalytic combustor makes possible the burning of heavy oils for downhole generation of steam to increase oil production, is of importance beyond the merely economic potential. Thus, the catalytic combustor and other igneslytic burners are important developments not only because they permit complete combustion of fuels without significant NO_x formation and because they make possible designs yielding reduced fuel consumption, but also because such combustors are serviceable in applications in which conventional combustors cannot be readily employed.     

Cogeneration plant in a pasta factory: Energy saving and environmental benefit

Italy produces approximately 4,520,000 tons of pasta annually, which is about 67% of its total productive potential. As factories need electric and thermal energy simultaneously, combined heat and power (CHP) systems are the most suitable. This paper describes a feasibility study of a CHP plant in a pasta factory in Italy while analyzing energy saving and environmental benefits. Commercially available CHP systems suitable for the power range of energy demand in pasta production use reciprocating engines or gas turbines. This study demonstrates how their use can reduce both energy costs and CO₂ equivalent greenhouse gas emission in the environment. An economic analysis was performed following the methodology set out by Italian National Agency for Technology, Energy and Environment (ENEA) based on a discounted cash flow (DCF) method called “Valore Attuale Netto” (VAN), which uses a cash flow based on the saving of energy when using different energy processes.     

New nuclear power generation in the UK: Cost benefit analysis

This paper provides an economic analysis of possible nuclear new build in the UK. It compares costs and benefits of nuclear new build against conventional gas-fired generation and low carbon technologies (CCS, wind, etc.). A range of scenarios are considered to allow for uncertainty as regards nuclear and other technology costs, gas prices and carbon prices.