Modelling the impact of energy taxation

Energy taxation in Sweden is complicated and strongly guides and governs district energy production. Consequently, there is a need for methods for accurate calculation and analysis of effects that different energy tax schemes may have on district energy utilities. Here, a practicable method to analyse influence of such governmental policy measures is demonstrated. The Swedish Government has for some years now been working on a reform of energy taxation, and during this process, several interest groups have expressed their own proposals for improving and developing the system of energy taxation. Together with the present system of taxation, four new alternatives, including the proposed directive of the European Commission, are outlined in the paper. In a case study, an analysis is made of how the different tax alternatives may influence the choice of profitable investments and use of energy carriers in a medium‐sized district‐heating utility. The calculations are made with a linear‐programming model framework. By calculating suitable types and sizes of new investments, if any, and the operation of existing and potential plants, total energy costs are minimized. Results of the analysis include the most profitable investments, which fuel should be used, roughly when during a year plants should be in operation, and at what output. In most scenarios, the most profitable measure is to invest in a waste incineration plant. However, a crucial assumption is, with reference to the new Swedish waste disposal act, a significant income from incinerating refuse. Without this income, different tax schemes result in different technical solutions being most profitable. An investment in cogeneration seems possible in only one scenario. It is also found that particular features of some alternatives seem to oppose both main governmental policy goals, and intentions of the district heating company. Copyright © 2002 John Wiley & Sons, Ltd.     

From hospital to municipal cogeneration systems: an Italian case study

A mixed integer linear programming model combined with a more traditional design by scenarios is proposed to optimize facilities size and operation mode of a municipal energy system involving significant civil centres and a hospital. Moving from the need of a new heat and power station for the local hospital due to the construction of new pavilions, the opportunity of involving other centres in the neighbourhood in a distributed cogeneration system is analysed, increasing system complexity step by step. Smaller cogeneration units tailored to hospital needs are rewarding ventures with relatively low risks but, in a country whose traditional power generation systems heavily rely on fossil fuels and where energy policy and market conditions can make it profitable to sell surplus power, district heating systems foster the installation of larger cogenerators and lead thereby to higher profits and to better performance as for primary energy savings and greenhouse gases emission reduction. Copyright © 2006 John Wiley & Sons, Ltd.     

以总能系统观点与用热终端高效化为特征的大中型火电机组联产供热系统新模式

以总能系统观点为指导,本文把联产供热系统视为由六个子系统组成,提出了各子系统火用效率的计算方法和这些效率对供热煤耗和成本的影响,并在此基础上提出了能适用于大中型火电机组的热电联产供热系统的新模式。新模式以用热终端高效化为特征,带动提高一系列子系统的火用效率,并把行之有效的,但一般是小规模孤立使用的现代化节能技术与节能设备,大规模地有机地与热电联产系统融为一体,扩大热网水的降温幅度,对热网水低品位能量进行梯级利用,形成采暖节能与增供电力相互促进相得益彰的机制,使联产供热的煤耗和供热成本大幅度地降低。文中结合世界技术现状和我国经济发展阶段分析了新模式的现实可行性。     

汽气共生热电气联产技术的研究

本文介绍了一种汽气共生热电气三联产新工艺．该工艺是以现有循环流化床技术为基础，集燃烧和气化工艺于一体，能同时产生民用煤气、蒸汽、电力．在小型热态试验以架上进行的一系列试验已成功地证实了该技术的可行性．在此基础上，一台蒸汽产量为７５ｔ／ｈ的热电气三联产装置已完成设计，正在实施之中．     

供热机组蒸汽氢电导率升高的原因及治理措施

通过对太原第一热电厂除盐水和15号机组的蒸汽品质参数的检测分析,找到了机组蒸汽氢电导率升高的原因,是锅炉补充水中有机物含量偏高;提出了解决此问题的措施,即增加反渗透膜处理设备。改造后检测结果表明:该措施是有效的。     

中小城镇多能源热电联供系统演化博弈分析

为解决中小城镇能耗高、能效低、经济承受力差等问题,促进中小城镇能源建设安全、经济和环保多目标协同发展,基于演化博弈理论,将能源建设多目标协同发展问题转化为寻求热电联供系统清洁低碳、安全高效的策略均衡问题。首先构建传统能源和新能源灰进化博弈模型,计算模型鞍点,寻求最优稳态均衡区域,分析影响均衡演化的因素,促进多能合作。其次,在多能合作的基础上,政府监管部门、供能商和用户作为博弈参与者,以安全可靠、高效经济和清洁环保为整体目标构建博弈模型,求取整体目标最优策略。最后以某县城为例进行多能合作和系统升级演化策略选择,支付总和不断降低,表明整体目标不断趋近最优;参与者概率分布越均衡,合作越稳定。     

DC‐linked hybrid generation system with an energy storage device including photovoltaic generation and gas engine cogeneration for residential houses

For the past few years, hybrid generation systems including solar panel and gas cogeneration have been used for residential houses. Solar panels can generate electronic power at daytime but not at night. But the power consumption of residential houses usually peaks in the evening. The gas engine cogeneration system can generate electronic power without such a restriction, and it also can generate heat power to warm up a house or to produce hot water. In this paper we propose a solar panel and gas engine cogeneration hybrid system with an energy storage device, combined by a DC bus. If a blackout occurs, the system still can supply electronic power for special house loads. We propose a control scheme for the system related to the charging level of the energy storage device and the voltage of the utility grid, which can be applied to both grid‐connected and standalone operation. Finally, we report experiments designed to demonstrate system operation and calculations for loss estimation. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(4): 29–46, 2013; Published online in Wiley Online Library ( wileyonlinelibrary.com ).DOI 10.1002/eej.22321     

分布式能源系统中燃气轮机热电联产运行方式的优化

为协调热电联产中热、电负荷的变化,解决热电供需不平衡问题,对分布式能源系统中燃气轮机热电联产的运行方式进行了优化。在传统"以电定热"和"以热定电"两种运行方式的基础上,提出通过添加辅助设备的方式来补充热电联产的运行方式。通过对优化前、后联产系统的总热效率进行的计算,验证了该方法的合理性,并对热电联产子系统的运行方式提出了建议。     

Experimental study of a domestic thermoelectric cogeneration system

Thermoelectric application for power generation does not appear to be appealing due to the low conversion efficiency given by the current commercially available thermoelectric module. This drawback inhibits its wide application because of the overall low thermal efficiency delivered by typical thermoelectric applications. This paper presents an innovative domestic thermoelectric cogeneration system (TCS) which overcomes this barrier by using available heat sources in domestic environment to generate electricity and produce preheated water for home use. This system design integrates the thermoelectric cogeneration to the existing domestic boiler using a thermal cycle and enables the system to utilise the unconverted heat, which represents over 95% of the total absorbed heat, to preheat feed water for domestic boiler. The experimental study, based on a model scale prototype which consists of oriented designs of heat exchangers and system construction configurations. An introduction to the design and performance of heat exchangers has been given. A theoretical modelling for analysing the system performance has been established for a good understanding of the system performance at both the practical and theoretical level. Insight has also been shed onto the measurements of the parameters that characterise the system performance under steady heat input. Finally, the system performance including electric performance, thermal energy performance, hydraulic performance and dynamic thermal response are introduced.     

Optimal operation of cogeneration system coordinated by aggregator for providing the demand and supply regulation capacity

Recent growth of renewable energy generations with natural variability, such as photovoltaic generation and wind turbine generation, would make the demand and supply control in a whole power system more difficult, and therefore, alternatives for demand and supply regulation resources would be required. The authors focus on cogeneration system (CGS) as one of regulation resources. In order to procure adequate volume of regulation capability, an aggregator coordinates a number of CGSs efficiently and flexibly considering the wide variety of electricity/thermal demands of CGS owners. This paper proposes a novel optimal operation strategy of CGS coordinated by the aggregator considering the energy balance and operation cost of individual CGS owner. This paper also demonstrates the availability of CGSs for regulation capability by numerical case studies in which the actual consumption profile is employed.