An assessment of the potential for cool storage application in the Thai commercial sector

The potential for cool storage air-conditioning (CSA) has been assessed for the Thai commercial sector. Computer simulations of customer groups of electric utilities were performed to evaluate investment and electricity costs for a number of tariff cases. Field evaluations were performed through interviews with decision makers, using a multi-criteria decision method. The results confirm good potential for application of CSA.     

A demand-side planning approach for the commercial sector of developing countries

A methodology is proposed for collecting end-use demand data for devising demand-side management programs in the commercial sector of developing countries. The characteristics of electricity end-uses in this sector are diverse. The end-use data have been collected in one or two segments of the commercial sector for simplicity and to save time and money. In the case of Northern Cyprus, hotels, a segment of this sector, have a high potential for utility load reduction. A survey was conducted in which questions were asked about the installed capacities of water and space heating, cooling, lighting and refrigeration and their time of use. Typical end-use load curves were obtained for the winter and summer seasons. It is estimated that summer peak could be reduced by approximately 11% if the DSM programs, costing just over half-a-million dollars, are adopted.     

An impact assessment of electricity and emission allowances pricing in optimised expansion planning of power sector portfolios

The present work concerns a systematic investigation of power sector portfolios through discrete scenarios of electricity and CO₂ allowance prices. The analysis is performed for different prices, from regulated to completely deregulated markets, thus representing different electricity market policies. The modelling approach is based on a stochastic programming algorithm without recourse, used for the optimisation of power sector economics under multiple uncertainties. A sequential quadratic programming routine is applied for the entire investigation period whilst the time-dependent objective function is subject to various social and production constraints, usually confronted in power sectors. The analysis indicated the optimal capacity additions that should be annually ordered from each competitive technology in order to substantially improve both the economy and the sustainability of the system. It is confirmed that higher electricity prices lead to higher financial yields of power production, irrespective of the CO₂ allowance price level. Moreover, by following the proposed licensing planning, a medium-term reduction of CO₂ emissions per MW h by 30% might be possible. Interestingly, the combination of electricity prices subsidisation with high CO₂ allowance prices may provide favourable conditions for investors willing to engage on renewable energy markets.     

Integrated resource planning in the power sector and economy-wide changes in environmental emissions

This paper analyzes the roles of key factors (i.e., changes in structure, fuel mix and final demand) on total economy-wide changes in CO₂, SO₂ and NO_x emissions when power sector development follows the integrated resource planning (IRP) approach instead of traditional supply-based electricity planning (TEP). It also considers the rebound effect (RE) of energy efficiency improvements in the demand side and analyzes the sensitivity of the results to variations in the values of the RE. A framework is developed to decompose the total economy-wide change in the emission of a pollutant into four major components, i.e., structural change-, fuel mix- , final demand- and joint-effects. The final demand effect is further decomposed into three categories, i.e., construction of power plants, electricity final demand and final demand related to electricity using equipments. The factor decomposition framework is then applied in the case of the power sector in Indonesia. A key finding in the case of Indonesia is that in the absence of the RE, there would be total economy-wide reductions in CO₂, SO₂ and NO_x emissions of 431, 1.6 and 1.3 million tons respectively during the planning horizon of 2006–2025 under IRP as compared to that under TEP. The decomposition analysis shows that the final demand effect would account for 38% of the total CO₂ emission reduction followed by the structural change effect (35.1%) and fuel mix effect (27.6%) while the joint effect is negligible. The study also shows that economy-wide CO₂ emission reduction due to IRP considering the RE of 45% would be 241 million tons as compared to 333 million tons when the RE is 25%.     

Integrated resource strategic planning: Case study of energy efficiency in the Chinese power sector

In the last quarter of the 20th century, many power companies used the integrated resource planning (IRP) approach in power expansion planning. Today, very few power companies use this approach because of the split between the power generation and distribution activities. It seems that, in some countries, long-term power system expansion planning has become a task of the central government. To help the government in this area, this paper proposes a new approach called the integrated resource strategic planning (IRSP). When combined with a smart grid, this approach can replace the IRP for the government’s power sector expansion. This paper introduces the necessity and possibility of using this new approach, presents a framework on how to use the approach, and justifies the effectiveness of this approach against the traditional power planning approach, with a case study in China. This paper concludes that if China follows the IRSP approach, it may be able to avoid or postpone up to 69 GW of power generation in the period 2009–2015. These measures could help mitigate 201.8 million tons of carbon dioxide (CO₂), 0.816 million tons of sulfur dioxide (SO₂), and 0.946 million tons of nitrogen oxide (NO_x).     

Integrated resource planning (IRP) and power sector reform in developing countries

The integrated resource planning (IRP) approach is one that considers both supply and demand-side options to meet the need for a resource, while minimising the costs accruing to the firm and to society. This paper focuses on IRP as a tool for the power sector in the light of the existing problems and the ongoing reforms in developing countries. It looks at the advantages that IRP would afford, juxtaposing these with the barriers to such a planning process—those encountered in the past as well as the possibilities in view of structural changes. It then discusses the policies that would enable the IRP approach to be usefully employed to mitigate the problems of the power sector. Although IRP has receded in importance in some areas of the world, there are perceptible benefits for developing countries; these could adopt such planning methods through the agents and the instruments suggested.     

State-of-the-art expansion planning of integrated power,natural gas,and hydrogen systems

Renewable hydrogen is considered key in the transition towards a carbon-neutral future. This is due to its spatio-temporal storage and sector coupling potential, which has seen it referred to as energy vector. However, many unresolved issues remain regarding hydrogen's large-scale deployment, e.g. least-cost production, optimal facility siting, and overall implications on power and energy systems. Expansion planning provides an option to study these issues in the holistic context of energy systems. To this end, this article presents a comprehensive review on state-of-the-art expansion planning models that consider integrated power, natural gas, and hydrogen systems. We cluster the existing literature in terms of modelling themes and scope, study the applied systematic modelling characteristics, and conduct an in-depth analysis of the technical model features regarding hydrogen technologies and natural gas infrastructure. Finally, we identify and discuss research gaps in the existing literature.     

An integrated approach for optimal coordination of wind power and hydro pumping storage

The increasing wind power penetration in power systems represents a techno‐economic challenge for power producers and system operators. Because of the variability and uncertainty of wind power, system operators require new solutions to increase the controllability of wind farm output. On the other hand, producers that include wind farms in their portfolio need to find new ways to boost their profits in electricity markets. This can be done by optimizing the combination of wind farms and storage so as to make larger profits when selling power (trading) and reduce penalties from imbalances in the operation. The present work describes a new integrated approach for analysing wind‐storage solutions that make use of probabilistic forecasts and optimization techniques to aid decision making on operating such systems. The approach includes a set of three complementary functions suitable for use in current systems. A real‐life system is studied, comprising two wind farms and a large hydro station with pumping capacity. Economic profits and better operational features can be obtained from the proposed cooperation between the wind farms and storage. The revenues are function of the type of hydro storage used and the market characteristics, and several options are compared in this study. The results show that the use of a storage device can lead to a significant increase in revenue, up to 11% (2010 data, Iberian market). Also, the coordinated action improves the operational features of the integrated system. Copyright © 2013 John Wiley & Sons, Ltd.     

An integrated optimization modeling approach for planning emission trading and clean-energy development under uncertainty

The growing concern for global warming caused by the increased atmospheric concentration of carbon dioxide (CO₂) has a significant effect on environmental and energy policies and economic activities, due to the ever-increasing use of fossil fuels such as coal, oil and natural gas throughout the world. A variety of complexities and uncertainties exist in CO₂-emission-related processes and various impact factors, such as CO₂-emission inventory, mitigation measure, and cost parameter. Decision makers face problems of how many clean-energy resources (or carbon credits) are needed to be replaced (or bought) by measuring electric-power benefits and uncertain economic penalties from random excess CO₂ exceeding to given discharge permits. In this study, an integrated optimization modeling approach is developed for planning CO₂ abatement through emission trading scheme (ETS) and clean development mechanism (CDM), where uncertainties presented in terms of fuzzy sets, interval values, and random variables can be addressed. The developed model is also applied to a case study of planning CO₂-emission mitigation for an electric-power system (EPS) that involves three fossil-fueled power plants (i.e., gas, oil and coal-power plants). Different trading schemes and clean-energy development plans corresponding to different CO₂-emission management policies have been analyzed. The results demonstrate that CO₂-emission reduction program can be performed cost-effective through emission trading and clean-energy development projects. Violation analyses are also conducted to demonstrate that different violation levels for model’s objective and constraints have different effects on system benefit and satisfaction degree as well as emission trading and clean-energy development.     

电热锅炉蓄热在空调采暖系统中的应用

介绍了电热锅炉蓄热的意义、系统形式及原理，在实例中对系统设计提出了新思路，并介绍了电热锅炉及蓄热槽的选型。     

A novel evolutionary algorithm for dynamic economic dispatch with energy saving and emission reduction in power system integrated wind power

An optimization algorithm is proposed in this paper to solve the economic dispatch problem that includes wind farm using the Chaotic Quantum Genetic Algorithm (CQGA). In addition to the detailed models of economic dispatch introduction and their associated constraints, the wind power effect is also included in this paper. The chaotic quantum genetic algorithm used to solve the economic dispatch process and discussed with real scenarios used for the simulation tests. After comparing the proposed algorithm with several other algorithms commonly used to solve optimization problems, the results show that the proposed algorithm is able to find the optimal solution quickly and accurately (i.e. to obtain the minimum cost for power generation in the shortest time). At the end, the impact to the total cost savings for power generation after adding (or not adding) wind power generation is also discussed. The actual implementation results prove that the proposed algorithm is economical, fast and practical. They are quite valuable for further research.     

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%.     

基于抽水蓄能电站调度的电力系统节煤减排效应分析

在全球日益关注能源和环境问题的今天,对清洁能源进行合理开发已成为世界能源建设的共识,其中抽水蓄能电站因具备技术成熟,调峰、调压、调相功能强等特点,在世界清洁能源开发建设中得到认可。抽水蓄能电站开发与运营管理在面对气候变化多样、节煤减排要求高的新形势下,需科学合理安排抽水蓄能调度运行机制,科学合理安排抽水蓄能在电力系统中的工作位置,更好发挥抽水蓄能电站节煤减排作用。通过对抽水蓄能电站不同运行方案进行分析,分析不同负荷曲线特性下抽水蓄能工作位置的差异,分析随着抽水蓄能不同工作方式的改变,分析其对电力系统中其他电源运行方式的影响,进而分析电力系统的燃煤消耗。该研究成果理论意义与实用价值均很大,可为我国抽水蓄能科学可持续开发建设提供参考依据。     

Electric sector capacity planning under uncertainty: Climate policy and natural gas in the US

This research investigates the dynamics of capacity planning and dispatch in the US electric power sector under a range of technological, economic, and policy-related uncertainties. Using a two-stage stochastic programming approach, model results suggest that the two most critical risks in the near-term planning process of the uncertainties considered here are natural gas prices and the stringency of climate policy. Stochastic strategies indicate that some near-term hedging from lower-cost wind and nuclear may occur but robustly demonstrate that delaying investment and waiting for more information can be optimal to avoid stranding capital-intensive assets. Hedging strategies protect against downside losses while retaining the option value of deferring irreversible commitments until more information is available about potentially lucrative market opportunities. These results are explained in terms of the optionality of investments in the electric power sector, leading to more general insights about uncertainty, learning, and irreversibility. The stochastic solution is especially valuable if decision-makers do not sufficiently account for the potential of climate constraints in future decades or if fuel price projections are outdated.     

Reliability evaluation of power system incorporating wind farm for generation expansion planning based on ANLSA approach

Reliability evaluation of power‐generating systems gives a mechanism to guarantee proper system operations in the face of different uncertainties including equipment failures. It is regularly not attainable to identify all possible failure states to figure the reliability indices because of the large number of system states engaged with system operations. Therefore, a hybrid optimization technique is required to analyse the reliability of the power system. This paper proposes a hybrid optimization technique to evaluate the reliability of a power system for the generation expansion planning incorporating wind energy source. The proposed hybrid methodology is the joined execution of both ant lion optimization algorithm (ALO) and lightning search algorithm (LSA), and it is named as ANLSA. ALO searching behavior is enhanced by LSA. Through the inherent convergence mechanisms, ANLSA search the meaningful system states. The most probable failure states contribute reliability indices of power generating system including mean down time (MDT), loss of load probability (LOLP), loss of load expectation (LOLE), loss of load frequency (LOLF), and expected demand not supplied (EDNS). Furthermore, ANLSA is utilized to assess the reliability of system under normal condition, integration of wind farm with capacity of 150 MW, and considering spinning reserve requirement (SRR). By then, the proposed work is actualized in MATLAB/Simulink platform and it is demonstrated on IEEE reliability test system (IEEE RTS‐79). Furthermore, the statistical analysis of proposed and existing techniques such as Monte Carlo simulation (MCS) and discrete convolution (DC) is considered. The comparison results demonstrate that proposed approach confirms its ability for evaluating the power system reliability.     

Long-term greenhouse gas emission and petroleum reduction goals: Evolutionary pathways for the light-duty vehicle sector

To meet long-term environmental and energy security goals, the United States must reduce petroleum use in the light-duty vehicle fleet by 70% and greenhouse gas emissions by a factor of ten compared to business-as-usual growth projections for the year 2050. A wedge-based approach was used to quantify the scope of the problem in real terms, and to develop options for meeting mid-century targets. Four mitigation mechanisms were considered: (1) improvements in near-term vehicle technologies; (2) emphasis on low-carbon biofuels; (3) de-carbonization of the electric grid; and (4) demand-side travel-reduction initiatives. Projections from previous studies were used to characterize the potential of individual mitigation mechanisms, which were then integrated into a light-duty vehicle fleet model; particular emphasis was given to systemic constraints on scale and rates of change.     

某供电大楼冰蓄冷空调测试的分析与评估

通过实测、调研某供电大楼冰蓄冷空调系统,从技术和优化运行角度对该冰蓄冷空调系统所测数据进行分析,指出该系统中蓄冰槽蓄冷率低、释冷不足的问题,并进行分析。接着论述了冰蓄冷空调系统的蓄冰槽不仅要在蓄冰量上与系统主机容量相匹配,同时还要考虑到蓄冰槽的蓄冰、融冰特性,最后说明系统运行管理人员对冰蓄冷空调系统在节能运行上产生的影响。     

The future choice of technologies and co-benefits of CO2 emission reduction in Bangladesh power sector

This paper examines the impacts of CO₂ emission reduction on future technology selection and energy use in Bangladesh power sector up to 2035 considering the base year 2005. It also examines the implications of CO₂ emission reduction targets on energy security of the country. The analysis is based on a long-term energy system model of Bangladesh using the MARKAL framework. The results show that the introduction of the CO₂ emission reduction targets directly affect the shift of technologies from high carbon content fossil-based to low carbon content fossil-based as well as clean, renewable energy-based technologies compared to the base scenario. With the CO₂ emission reduction target of 10–30%, the cumulative net energy imports during 2005–2035 would be reduced in the range of over 1400 PJ to 4898 PJ compared to the base scenario emission level. The total primary energy requirement would be reduced in the range of 5.5–15.2% in the CO₂ emission reduction targets and the primary energy supply system would be diversified compared to the base scenario.     

Power generation expansion planning with emission control: a nonlinear model and a GA‐based heuristic approach

This paper presents an application of genetic algorithms (GA) for solving the long‐term power generation expansion planning (PGEP) problem, a highly constrained nonlinear discrete optimization problem. The problem is formulated into a mixed integer nonlinear programming (MINLP) program that determines the most economical investment plan for additional thermal power generating units over a planning horizon, subject to the requirements of power demands, power capacities, loss of load probability (LOLP) levels, locations, and environmental limitations. Computational results show that the GA‐based heuristic method can solve the PGEP problem effectively and more efficiently at a significant saving in runtime, when compared with a commercial optimization package. Copyright © 2005 John Wiley & Sons, Ltd.     

Energy conservation and emission reduction policies for the electric power industry in China

Because of China's increasingly limited energy supplies and serious environmental pollution, much attention has been paid to conserving energy and reducing emissions to help the country's economy achieve sustainable development. As the electric power industry is the largest consumer of coal resources in China and also emits high levels of air pollutants each year, the Chinese government has enacted many technical and economic policies for energy conservation and emission reduction in the last few years. These policies are summarized in this paper, along with relevant laws and medium- and long-term plans, all of which address ideas such as adjusting the power generation mix, promoting demand-side management, introducing energy-efficient scheduling, and installing desulfurization units. The paper also assesses the results of these policies by analyzing several key indicators of energy consumption and emissions. The analysis shows that although some progress has been made in conserving energy and reducing emissions, substantial work is still required for China to catch up with developed countries. Some suggestions for future work are provided.