Use of multicriteria decision analysis methods for energy planning problems

Most decision making requires the consideration of several conflicting objectives. The term multiple criteria decision analysis (MCDA) describes various methods developed for aiding decision makers in reaching better decisions. Energy planning problems are complex problems with multiple decision makers and multiple criteria. Therefore, these problems are quite suited to the use of MCDA. A multitude of MCDA methods exists. These methods can be divided in three main groups; value measurement models, goal, aspiration and reference level models, and outranking models. Methods from all of these groups have been applied to energy planning problems, particularly in the evaluation of alternative electricity supply strategies. Each of the methods has its advantages and drawbacks. However, we cannot conclude that one method generally is better suited than the others for energy planning problems. A good alternative might be to apply more than one method, either in combination to make use of the strengths of both methods, or in parallel to get a broader decision basis for the decision maker. Until now, studies of MCDA in energy planning have most often considered energy networks with only one energy carrier. More advanced energy systems with multiple energy carriers have been neglected, even though this field ought to be suitable for use of MCDA due to its high complexity, many decision makers and many conflicting criteria.     

Determining the most sustainable lignocellulosic bioenergy system following a case study approach

The paradigm shift from fossil to renewable energy sources is driven, largely, by a growing sustainability awareness, necessitating more sophisticated measurements in terms of a wider range of criteria. Technical efficiency, financial profitability, environmental friendliness and social acceptance are some of the aspects determining the sustainability of renewable energy systems. The resulting complexity and sometimes conflicting nature of these criteria constitute major barriers to the implementation of renewable energy projects.The Worcester biomass procurement area in the Western Cape Province, South Africa, is used as a case study. It provides a blueprint for measuring the impacts of lignocellulosic bioelectricity systems – using life-cycle assessment (LCA), multi-period budgeting (MPB), geographic information systems (GIS) and multi-criteria decision-making analysis (MCDA), among others – and for prioritising the relevant criteria to determine the most sustainable technological option.Following the LCA approach, 37 plausible lignocellulosic bioenergy systems were assessed against five financial-economic, three socio-economic and five environmental criteria. On translating the quantitative performance data into a standardised ‘common language’ of relative performance, an expert group attached weights to the considered criteria, using the analytical hierarchy process (AHP). Assuming the prerequisite of financial-economic viability, the preferred option comprises a feller-buncher for harvesting, a forwarder for biomass extraction, mobile comminution at the roadside, secondary transport in truck-container-trailer combinations and an integrated gasification system for the conversion into electricity. This approach illustrates how to internalise externalities as typical market failures, aiding decision makers to choose the most sustainable bioenergy system.     

Weighting methodologies in multi‐criteria evaluations of combined heat and power systems

Several combined heat and power (CHP) system options are presented to assess and compare with respect to the end users' requirements. According to the obtained data from literature, 16 kinds of CHP systems are evaluated using gray relational method in multi‐criteria, such as technology, economy, environment, and society. The results depend greatly on the criteria weights in multi‐criteria evaluations. Aiming to obtain rational result, this paper reviews the weighting method briefly and proposes an optimal combined weighting method to consider the subjectivity of decision‐maker and the objectivity of measurement data. The singular value decomposition aggregation method is employed to verify the rationality of evaluation result. Through multi‐criteria evaluation and discussions, the combination weighting method is recommended to be used in the selection of CHP schemes. Finally, the best CHP system is selected and the most conspicuous factors having great impact on CHP system with respect to the users' requirements are given out. Copyright © 2009 John Wiley & Sons, Ltd.     

Multi-criteria model for sustainable development using goal programming applied to the United Arab Emirates

Sustainable development requires implementing suitable policies integrating several competing objectives on economic, environmental, energy and social criteria. Multi-Criteria Decision Analysis (MCDA) using goal programming is a popular and widely used technique to study decision problems in the face of multiple conflicting objectives. MCDA assists policy makers by providing clarity in choosing between alternatives for strategic planning and investments. In this paper, we propose a weighted goal programming model that integrates efficient allocation of resources to simultaneously achieve sustainability related goals on GDP growth, electricity consumption and GHG emissions. We validate the model with application to key economic sectors of the United Arab Emirates to achieve sustainable development goals by the year 2030. The model solution provides a quantitative justification and a basis for comparison in planning future energy requirements and an indispensable requirement to include renewable sources to satisfy long-term energy requirements.     

Assessment of hydrogen production methods via integrated MCDM approach under uncertainty

Energy has a crucial role for the existence and social well-being of human. Among various options, hydrogen is the promising energy carrier for sustainable energy systems. As an important source of hydrogen, Hydrogen Sulphide (H₂S) is abundantly found in Black Sea waters and known as an environmental pollutant. The main aim of this study is to evaluate Thermochemical, Electrochemical, Thermal, Photochemical, Plasma, and Thermal methods as decomposition methods, which meet sustainability aspects better than other technologies, based on expert opinions. As sustainable criteria, economically feasibility, ecologically feasibility, efficiency, process simplicity, energy requirement, safety and reliability, applicability and operational suitability and technical maturity are considered to determine the most appropriate hydrogen production method. In this sense, we have suggested a new integrated Multi-Criteria-Decision-Making (MCDM) methodology consisting of stepwise weight assessment ratio analysis (SWARA) with fuzzy set theory (FST) and Weighted Aggregated Sum Product Assessment (WASPAS) by employing interval valued intuitionistic fuzzy sets (IVIFS) in the selection process. The contribution of the study is not only proposing a new method which hybridizes the SWARA and WASPAS under uncertainty but also selecting the most sustainable Hydrogen production method utilizing from H₂S in the Black Sea in Turkey, considering sustainable criteria which are unavoidable in energy management problems. At the end, the results are discussed, and sensitivity and comparative analyses are utilized to check the robustness and feasibility of solutions. Consequently, electrochemical is selected as the best and most appropriate hydrogen production method in terms of providing high efficiency in conversion and sustainable processes, i.e handling, transporting and storing harmful chemicals.     

Air co-gasification process of LDPE/HDPE waste based on thermodynamic modeling: Hybrid multi-criteria decision-making techniques with sensitivity analysis

Gasification process is an efficient thermochemical disposal technique and is growing fast in the plastic waste field, nowadays. Co-gasification of low-density and high-density polyethylene waste with different composition ratios was developed in this study and subjected to a hybrid multi-criteria decision-making (MCDM) techniques after validation by comparing with experimental data. A comprehensive parametric study was conducted by considering interaction effects of gasification parameters on the outputs. The MCDM problem involved eleven alternatives and five energy, environmental and economic criteria of gasification performance indicators including hydrogen production, energy efficiency, carbon dioxide emission, heating value of syngas and purchasing cost. The criteria weighting was performed using analytical hierarchy process, Shannon entropy technique and their composite weighting method. TOPSIS and VIKOR techniques were coupled by criteria weighting methods for alternative ranking. L0H100 alternative, i.e. composition of 0 wt% of low-density polyethylene waste and 100 wt% of high-density polyethylene waste, was the best alternative in almost all cases. This alternative had the minimum CO₂ emission of 4.98 g/mol, the minimum purchasing cost of 0.96 $/kg and led to the maximum heating value of 126.8 kJ/mol. The findings revealed that VIKOR technique was sensitive to the criteria weights; however, TOPSIS method was independent from the changing the criteria weights.     

冷热电联产系统新评价准则研究

从冷热电联产系统能量梯级利用的本质特征提出了能量梯级利用率的评价准则.该准则由发电、制冷与供热的能量利用率分别乘以不同的权重系数后累加得到.先确定比较的基准点,然后采用层次分析的方法得出基准点各能量利用率的权重系数.对基准点权重系数根据冷热产品温度及环境温度进行修正可得到其它情况的权重系数值.结合实际的联产系统算例,给出了这种评价准则的使用方法,并与原有的评价准则进行分析对比.结果表明,该评价准则具有合理性,可作为冷热电联产系统评价比较的实用方法.     

Prioritization of potential locations for harnessing wind energy to produce hydrogen in Afghanistan

Due to the devastating ecological effects and constrained reserves of fossil fuels, renewable energies are now globally accepted as viable alternative sources of energy. Among renewable energy sources, wind energy has become globally popular, primarily because wind farms can be rapidly built and easily maintained at a relatively low cost. Wind-powered hydrogen production is an effective solution for storing the excess energy output of wind farms. The hydrogen produced in this way can be used not only in fuel cells but also in cooling, oil, gas, and petrochemical fields. As a country devastated by war and instability, Afghanistan has major energy generation challenges and a substantially large power supply deficiency. However, there are good wind energy potentials in several parts of this country. There are also several hydrogen-consuming fields in Afghanistan that can benefit from hydrogen production from wind energy. This paper endeavored to distinguish the appropriate areas in Afghanistan for harvesting wind energy for hydrogen production using multi-criteria decision-making techniques. Eleven criteria were utilized to prioritize 20 Afghan provinces with wind energy potential. The Step-wise Weight Assessment Ratio Analysis (SWARA) was utilized to weight the criteria and Evaluation based on Distance from Average Solution (EDAS) were utilized to prioritize the provinces. Then, ARAS, TOPSIS, and VIKOR methods were used to validate the resultants. For criteria weighting with SWARA, “wind speed”, “wind power density” and “area of windy regions” with weights of 0.1423, 0.1356, and 0.1221 were introduced as the most significant criteria for this ranking. In all the rankings, Herat, Farah, and Jowzjan were identified as the top three most suitable provinces for wind power generation. The power output and hydrogen output to be achieved in Herat province using a 900-kW turbine were estimated to 2558.4 MW per year and 41.4 tons per year, respectively.     

Multicriteria analysis for the selection of the most appropriate energy crops: the case of Cyprus

Energy crops are considered key actors in meeting the international and European carbon reduction targets, increasing the national energy security through renewable energy production, mitigating climate change impacts, and promoting sustainability. Multicriteria analysis is a suitable decision-making tool for the energy sector, where the final decisions have to consider for a range of aspects, and can be utilised as well for deciding on appropriate energy crops. In this paper, a popular multicriteria method, PROMETHEE, is employed for the identification of the most optimal energy crops for their exploitation in Cyprus. The criteria and the weights of each are defined, and accordingly five different scenarios are developed and examined. The obtained results indicated that the promotion of second-generation energy crops is more ideal in terms of the set objectives, as well as more sustainable than the exploitation of any first-generation energy crop.     

Sustainability assessment of wood-based bioenergy – A methodological framework and a case-study

The sustainability of the utilization of wood biomass for energy and other purposes has been widely assessed in different studies. Especially discrete methods from the family of Multi-Criteria Decision Analysis (MCDA), such as Outranking methods, Multi-Attribute Utility Theory, and Analytic Hierarchy Process (AHP) are often applied. AHP is considered one of the most promising options to be used in sustainability assessments, because it is comprehensible to apply and it incorporates the preferences of decision-makers in an advanced manner. In this study, we present a theoretical multi-dimensional framework based on a modified version of AHP for assessing sustainability and apply it in a case of wood-based bioenergy production in eastern Finland. The framework includes four dimensions of sustainability and life cycle phases from the acquisition of raw material to manufacturing the final product. The production systems used in the empirical sustainability assessments are a local heat production plant, a combined heat and power production plant, and a wood pellet processing plant. Local sustainability experts identified indicators relevant at the regional scale. The impact assessment data were obtained from literature, by interviewing the managers of the bioenergy plants, and from a postal survey administered to local people. The local heat provider received the highest sustainability index; however, there were no considerable differences between the sustainability indexes. None of the bioenergy production systems can be considered the most sustainable regardless of the assumptions employed in the framework. The framework provided the basis for a quantitative, interdisciplinary approach to assess sustainability.     

A comparison of the energy and carbon implications of new systems of energy provision in new build housing in the UK

The built environment needs to develop sustainable, decarbonised, low energy systems and approaches that are socially acceptable and economically beneficial. The UK mainstream house construction industry is being driven, through policy and regulation, towards achieving this end without evidence of how these new systems of provision are used by passively adopting households. In this paper energy use, consequential emissions of CO₂, and annual running costs for a case study comprising 14 newly constructed low energy affordable homes are evaluated. Four different energy typologies are compared: ground sourced heat pumps; active solar (thermal and photovoltaic); passive solar and mechanical ventilation with heat recovery; conventional high efficiency gas boiler. The carbon embodied in construction and emitted over a 20 year occupation period for each typology is calculated. Ground source heat pumps have the highest annual primary energy demand, CO₂ emission and annual running costs over the 20 year period. The homes with active solar technologies provided most benefit across all three evaluation criteria. Energy and CO₂ emissions associated with end uses other than heating were similar to the UK average. This poses significant questions on the probability of policy application in the real world to deliver projected reductions in emissions of CO₂.     

Sustainable energy planning by using multi-criteria analysis application in the island of Crete

The sustainable energy planning includes a variety of objectives, as the decision-making is directly related to the processes of analysis and management of different types of information (technological, environmental, economic and social). Very often, the traditional evaluation methods, such as the cost-benefit analysis and macro-economic indicators, are not sufficient to integrate all the elements included in an environmentally thorough energy plan. On the contrary the multiple criteria methods provide a tool, which is more appropriate to assemble and to handle a wide range of variables that is evaluated in different ways and thus offer valid decision support.     

A fuzzy multi-criteria decision-making model for trigeneration system

The decision making for trigeneration systems is a compositive project and it should be evaluated and compared in a multi-criteria analysis method. This paper presents a fuzzy multi-criteria decision-making model (FMCDM) for trigeneration systems selection and evaluation. The multi-criteria decision-making methods are briefly reviewed combining the general decision-making process. Then the fuzzy set theory, weighting method and the FMCDM model are presented. Finally, several kinds of trigeneration systems, whose dynamical sources are, respectively stirling engine, gas turbine, gas engine and solid oxide fuel cell, are compared and evaluated with a separate generation system. The case for selecting the optimal trigeneration system applied to a residential building is assessed from the technical, economical, environmental and social aspects, and the FMCDM model combining analytic hierarchical process is applied to the trigeneration case to demonstrate the decision-making process and effectiveness of proposed model. The results show that the gas engine plus lithium bromide absorption water heater/chiller unit for the residential building is the best scheme in the five options.     

地形复杂的风电场资源评估误差分析方法

由于计算模型本身的限制,风能资源地图分析与应用程序(WAsP)不能准确模拟复杂地形中风的流动变化情况,用其评价复杂地形风电场的风能资源时存在一定误差.目前,主要采用RIX方法来评估WAsP在复杂地形中的风速预测误差,长期以来一直缺少根据风速预测误差来评估风电场发电量预测误差的有效方法.文章在RIX方法的基础上,对WAsP应用于复杂地形风电场发电量预测的误差进行了研究,结合工程实践提出了一种发电量误差评估方法;根据某风电场实际发电量数据对提出的评估方法进行了验证,证明其有效性和实用性.     

Hydrogen from solar energy,a clean energy carrier from a sustainable source of energy

Solar energy is going to play a crucial role in the future energy scenario of the world that conducts interests to solar-to-hydrogen as a means of achieving a clean energy carrier. Hydrogen is a sustainable energy carrier, capable of substituting fossil fuels and decreasing carbon dioxide (CO₂) emission to save the world from global warming. Hydrogen production from ubiquitous sustainable solar energy and an abundantly available water is an environmentally friendly solution for globally increasing energy demands and ensures long-term energy security. Among various solar hydrogen production routes, this study concentrates on solar thermolysis, solar thermal hydrogen via electrolysis, thermochemical water splitting, fossil fuels decarbonization, and photovoltaic-based hydrogen production with special focus on the concentrated photovoltaic (CPV) system. Energy management and thermodynamic analysis of CPV-based hydrogen production as the near-term sustainable option are developed. The capability of three electrolysis systems including alkaline water electrolysis (AWE), polymer electrolyte membrane electrolysis, and solid oxide electrolysis for coupling to solar systems for H₂ production is discussed. Since the cost of solar hydrogen has a very large range because of the various employed technologies, the challenges, pros and cons of the different methods, and the commercialization processes are also noticed. Among three electrolysis technologies considered for postulated solar hydrogen economy, AWE is found the most mature to integrate with the CPV system. Although substantial progresses have been made in solar hydrogen production technologies, the review indicates that these systems require further maturation to emulate the produced grid-based hydrogen.     

Sustainability assessment of cogeneration sector development in Croatia

The effective and rational energy generation and supply is one of the main presumptions of sustainable development. Combined heat and power production, or co-generation, has clear environmental advantages by increasing energy efficiency and decreasing carbon emissions. However, higher investment cost and more complicated design and maintenance sometimes-present disadvantages from the economical viability point of view. As in the case of most of economies in transition in Central and Eastern Europe, Croatia has a strong but not very efficient co-generation sector, delivering 12% of the final energy consumption. District heating systems in the country's capital Zagreb and in city of Osijek represent the large share of the overall co-generation capacity. Besides district heating, co-generation in industry sector is also relatively well developed. The paper presents an attempt to assess the sustainability of Croatian co-generation sector future development. The sustainability assessment requires multi-criteria assessment of specific scenarios to be taken into consideration. In this respect three scenarios of Croatian co-generation sector future development are taken into consideration and for each of them environmental, social and economic sustainability indicators are defined and calculated. The assessment of complex relationships between environmental, social and economic aspects of the system is based on the multi-criteria decision-making procedure. The sustainability assessment is based on the General Sustainability Index rating for different cases reflecting different criteria and their priority. The method of sustainability assessment is applied to the Croatian co-generation sector contributing to the evaluation of different strategies and definition of a foundation for policy related to the sustainable future cogeneration sector development.     

Life cycle analysis for future photovoltaic systems using hybrid solar cells

Global climate change concerns have lead to growing demand for renewable energy sources (RES). However the viability of these sources is critically dependent on environmental, economic and technological considerations. This paper focuses on the environmental aspect of future photovoltaic (PV) systems which are assessed through life cycle analysis (LCA). Previous LCA studies on commercially available PV systems are reviewed. The sustainable evaluation methods used in these studies are also discussed. These methods are applied to the hybrid quantum dot (QD)-based solar cells currently under development within a project between the University of Manchester and Imperial College London. The aim of this project is to develop affordable solar cells with efficiencies up to 10% for micro-generation applications. Presently hybrid QD-based solar cells are not commercially fabricated; therefore the study is mostly based on very small laboratory-scale production. For easy comparability 10% conversion efficiency and 25 years lifetime are initially assumed. Lower conversion efficiencies and shorter lifetimes likely to initially characterise emerging PV technologies such as the hybrid QD-based solar cells are discussed. Comparable criteria for sustainability of electricity-generating systems namely net energy ratio (NER), energy pay-back time (EPB-T) and CO₂ emissions per unit generated during lifetime are found to be lower than current commercially available PV modules.     

Sustainable energy planning decision using the intuitionistic fuzzy analytic hierarchy process: choosing energy technology in Malaysia

Energy consumption for developing countries is sharply increasing due to the higher economic growth due to industrialisation along with population growth and urbanisation. The increasing demand of energy leads to global energy crisis. Selecting the best energy technology and conservation requires both quantitative and qualitative evaluation criteria. The fuzzy set-based approach is one of the well-known theories to handle fuzziness, uncertainty in decision-making and vagueness of information. This paper proposes a new method of intuitionistic fuzzy analytic hierarchy process (IF-AHP) to deal with the uncertainty in decision-making. The new IF-AHP is applied to establish a preference in the sustainable energy planning decision-making problem. Three decision-makers attached with Malaysian government agencies were interviewed to provide linguistic judgement prior to analysing with the new IF-AHP. Nuclear energy has been decided as the best alternative in energy planning which provides the highest weight among all the seven alternatives.     

Multi-criteria evaluation for the optimal adoption of distributed residential energy systems in Japan

Evaluation of sustainable residential energy system is complex process, in which not only the economic aspect, but also the energetic and environmental effects should be taken into consideration. In this paper, an integrated design and evaluation model has been developed, by combing linear programming and multi-criteria evaluation method, in order to determine the optimal residential energy system while considering different types of information. As an illustrative example, an investigation is conducted for a typical residential building in Kitakyushu, Japan. A set of residential energy alternatives, including both conventional energy and renewable energy applications, are assumed for adoption. Based on the optimal design results from the linear programming, the various alternatives have been assessed against economic, energetic and environmental criteria. According to the evaluation results, currently, renewable energy systems are not competitive unless strong attention is paid to the environmental benefits. All electric system may be a transitional consideration before reaching an actual low carbon residential energy system. Furthermore, the evaluation result is greatly influenced by the criteria priority, as well as the evaluation method.     

Wind farm site selection from the perspective of sustainability: A novel satisfaction degree‐based fuzzy axiomatic design approach

As a clean and renewable energy resource, wind energy is the most mature, environmentally friendly, and most commercially developed new energy resource in the world. Therefore, it is of great importance to determine the best location of wind farms to ensure the sustainable development of wind energy. However, since wind farm site selection often involves multiple criteria, which include qualitative and quantitative criteria, there may be conflicts between these criteria, so wind farm site selection is a complex multi‐criteria decision‐making (MCDM) problem. Therefore, the objective of this study is to propose a novel integrated MCDM approach using a fuzzy analytic hierarchy process and satisfaction degree‐based fuzzy axiomatic design (AD) to determine the optimal onshore wind farm site under a hybrid decision information environment. First, based on the literature review and experts' opinion, the evaluation index system for wind farm site selection is built from a sustainable perspective, which includes geographic, technical, economic, social, and environmental criteria. Second, fuzzy analytic hierarchy process is applied to determine criteria weights. Third, the satisfaction degree‐based fuzzy AD is employed to evaluate and rank alternatives under a hybrid decision information environment. Finally, a case study is used to illustrate the reliability and advantages of the method proposed in this paper. In addition, the information content of each alternative is calculated by aggregating the evaluation matrix of experts, and the results are IC₁ = 0.058, IC₂ = 0.096, IC₃ = 0.16, IC₄ = ∞, IC₅ = ∞, and IC₆ = 0.226. Then the satisfaction degree of each alternative is S₁ = 0.629, S₂ = 0.545, S₃ = 0.501, S₄ = 416, S₅ = 389, and S₆ = 0.463. Thus, the best wind farm site is A₁. Moreover, the results show that the method proposed herein is flexible and can effectively deal with the wind farm site selection problem. Although this paper chooses China as a case study, the proposed method herein is also applicable to other countries or regions.