英文原文 Multi-criteria selection of electric power plants using analytical hierarchy process Abstract This paper uses analytical hierarchy process (AHP) methodology to perform a comparison between the different electricity power production options in Jordan. The systems which were considered, in addition to fossil fuel power plants, are nuclear, solar,wind, and hydro-power. Results on cost to benefit ratios show that solar, wind, end hydro-power may be the best alternatives for electric power production. Nuclear electricity turns out to be the worst choice, followed by fossil fuel electric power. 1. Introduction Jordan is a non-oil producing Middle-Eastern country. It relies heavily on importing oil from neighboring countries. Most of the electric power that is generated to serve different sectors of the country is produced from power plants that use fossil fuel. This fuel is either totally imported such as petroleum hydrocarbon fuel, or partially local (only with small percentage) such as natural gas. The 1996 electrical energy consumption in Jordan reached a value of 6000 GWh. About 93% of his amount was produced by the National Electric Power Company (NEPCO) which is the main electricity supplier in the country 1. Other options or alternatives of energy sources for electric power generation must tee considered. These options may include nuclear, solar, wind, or hydro-electric energies. The Jordanian experience with electricity generation using solar and wind energy technology has been on the small and experimental scale. These renewable energy systems were utilized in mostly remote areas of Jordan. They are used to generate electric power for individual application such as clinics, lighting, and educational television sets. The remote village of Jurf Eldaraweesh located in the Jordan desert of a population of 600, is the best example 2. The necessary electrical energy is totally supplied by solar and wind energy conversion systems. In this paper, oil-fired power plants in addition to other alternatives are being evaluated. The other alternatives include nuclear, solar, wind and hydro-power. A brief description of various power plant technologies will be presented. Using a decision-support system through a multiple criteria analysis, such as AHP, an attempt will be made to assist decision makers to evaluate the use of the above technologies which can be most suitable for electrical power production in Jordan. 2. Fossil-fuel electrical power plants In general, fossil fuels are non-renewable. They originate from the earth as a result of decomposition and chemical conversion of organic materials. They come in three organic forms: (1) solid, e.g. coal and oil shale; (2) liquid, e.g. most petroleum products, and (3) gas, e.g. natural gas. Coal represents the largest fossil-fuel energy resource in electric power generation 3,4. Oil shale is a fossil fuel that exists in Jordan in abundance, but with unattractive physical properties. First, like all oil shales, it has a low heating value due to the high ash content 5. Secondly, the Jordanian oil shale has sulfur contents, ranging 46% 6. Because of low prices of petroleum world wide the utilization of solid fossil fuels, such as oil shale, cannot be feasible at the time being. Therefore, oil shale power plants can not be considered to be competitive 3. Petroleum and natural gas are the main fuels used for the electric power generation in Jordan in addition to small hydro-powered electricity generation plants. Table 1 represents the existing electrical power plants in Jordan 1. 3. Electricity power production using solar energy Since the 1970s solar energy has received the greatest attention of all renewable energy sources all over the world. Many regard it as the solution for cleaner environment and may be the alternative to fossil and nuclear fuels. Thus, solar energy has been the object for production of electrical power. Many studies and experiences have shown that solar thermal power plants are one of the most economic forms of solar electricity generation. Solar energy can be converted into electricity by photovoltaic cells, but this process is mostly convenient and suitable for small applications only. Stand alone photovoltaic power systems were proposed for electrification of remote areas of which they are located outside the electricity grid-connection supply system 7. On the other hand, solar energy can be converted into thermal energy by means of solar collectors or concentrators. A working fluid is used to convert the thermal energy into mechanical energy which is then converted into electricity. Unlike photovoltaics, large amounts of electrical power can be generated from such plants. The types of receivers that can be seriously considered are: (1) central receivers, (2) dispersed or distributed receivers and (3) solar ponds. Like most countries of the Middle East, Jordan enjoys long periods of sunshine. The local weather has over 300 cloudless days per year. Future technology suggests that the Dead Sea itself can be used as 450 km2 solar lake, operating a 2500 MW power plant 8. In a recent study, the potential of using the Dead Sea as a large natural solar pond for generation of electricity in Jordan was explored 9. Kribus et al. 10 have shown new solar power plant concept by incorporating new developments of solar power optics, high performance air receivers, and solar-to-gas turbine interface. In terms of economical point of view, Kolb 11 found hybrid power towers to be superior to solar-only plants with the same field size. There is a number of solar thermal power plants in operation around the world. They are found to be one of the most economical systems for generating electricity 12,13. Recently, the co-generation of electricity and potable water by utilization of solar energy was carried out 14,15. This kind of system looks attractive in remote areas where both water is scares and electricity grid is not available. The system is capable of producing 30 MWe or more. 4. Electrical power production using wind energy It is very well established that wind energy resource is large and globally widespread. For different applications, it is clear that wind energy can be competitive in many locations 1618. Wind energy can be used in many applications such as water pumping 19, and water desalination 20. It can also be used for the electrical power generation using wind energy conversion system 21. Wind power is expected to be one of the least expensive forms of new electrical generation in the twenty-first century 22. With global efforts to become tough on fossil fuel related energy systems and to reduce the emissions of CO2 significantly, this will most likely introduce lower cost wind systems. For example, large wind power plants at good wind sites using emerging technologies can deliver electricity into utility grid at low prices that are becoming competitive with those of conventional power generation. Wind power plants can use hundreds of wind turbines that range in size from 50 to 500 kW each located in some remote areas. The plants computerized and control center operates similar to fossil fuel plants, except it does not have to be in sight of turbines. In a recent study a model of wind power plant for isolated location was presented 23. Increases in the prices of fuel and cost of fossil fuel plants and in relying less on non-renewable energy resources, decrease the value and cost of wind power generation systems significantly 24,25. There are number of sites in Jordan with potentially high wind speeds, that can be utilized for this purpose 26,27. Habali et al. 27 have presented an evaluation of wind energy in Jordan and its application for electrical power generation. A total of 11 wind sites were considered covering the entire country. The three most potential sites in Jordan are found to be Ras Muneef, Mafraq, and Aqaba. They have wind speeds that range from 4 to 23 ms throughout 80% of the whole year. 5. Hydro-electric power plants Hydro-electric power plants can provide a basis for evaluating the potential of renewable sources of energy. When compared to other thermal power plants, they are found to be conventional and reliable. Some countries utilize this form of free natural energy into useful type of electrical power. For example, 11% of the electric power produced in the USA was provided by hydro-electric power 4. Egypt and Turkey, countries of this region, also utilize this type of power for generating electricity at low costs. A number of studies were involved in utilizing hydro-power in Jordan for the purpose of electricity production 28, water desalination 29,30, and both electricity production and water desalination 8,31. These studies, mainly, considered the linkage of Red and Dead Seas with a canal to generate hydro-power. The Dead Sea is about 400 m below sea level (BSL), it is roughly 200 km to the north of the Gulf of Aqaba. It is an extension of the Red Sea. The Dead Sea has no outlet; its water level is a function of inflow and evaporation of water. For thousands of years the Dead Sea maintained an equilibrium with the annual inflow and evaporation of water. This resulted in a constant sea level. For example, in 1930 the surface of the Dead Sea was measured at its historical elevation of about 390 m BSL. The Jordan River is considered to be the main tributary of the Dead Sea. Over the years due to increase in population and agricultural development, water was diverted for irrigation in the Jordan Valley and neighboring countries. Therefore, its elevation was forced to drop, drastically; in 1993 it was 408 m BSL. To halt this trend, it will be necessary to introduce a substantial amount of new water to the sea. Sea water from the Red Sea can be used as a source of wafer needed for diversion into the Dead Sea. This diversion can be used to either maintain the sea at its current level and thus stop its dropping, or even to bring it back to its historical level. The power obtained from such process can be used to generate electricity and allow even more fresh water to be diverted from the Jordan River. 6. Nuclear power plants It is very well known fact that for those countries that rely on but do not have oil, nuclear power becomes a strategic as well as economic necessity 3. Nuclear power plants can pay for their capital cost in a few short years. Thus, a less expensive electric power can be produced without relying on importing foreign oil, or at least the reduction in oil import. Some believe that one day oil will be depleted, and nuclear power becomes a must. Therefore, it is important to start this technology now in order to assure the country would not be left behind when the time comes to have to use nuclear technology. Nuclear electricity offers an advantage from an environmental point of view and air pollution. It has less environmental problems that are associated with oil-fired power plants. Thus, nuclear power is bound to become the choice of power for the future. There are some difficulties that are associated with nuclear power, namely, waste disposal and safety. If this kind of energy becomes popular in most countries around the world, solutions to these problem become a must and thus be found. 7. The analytic hierarchy process The analytic hierarchy process (AHP), which was developed by Saaty 32, has been an effective tool in structuring and modeling multi-objective problems. For example, it has been applied to business decisions 33, selection of areas of research and development programs 34, real estate investments 32, water policies 35, and water desalination technologies 29. AHP can assist decision makers to evaluate a problem in the form of a hierarchy of references through a series of pairwise comparisons of relative criteria. Briefly, relative weights are determined through pairwise comparison. The method can be applied by breaking down the unstructured complex scorecard problems into component parts. Hierarchical orders are then arranged by forming value tree structures. Subjective judgments on the relative importance of each part are represented by assigning numerical values; the numerical values are selected in accordance to Fig. 1. These judgments are then synthesized in the use of eigenvectors to determine which variables have the highest priority. The decision regarding the selection of an optimum system for electricity power generation in Jordan was evaluated according to benefits and costs. Cost-tobenefit analysis is obtained by separating costs from benefits and structuring separate hierarchies for benefits and costs. They were constructed as shown in Figs. 2 and 3. The overall objective (goal) for both hierarchies was to select an optimum system (i.e. level1). Fig. 2 shows the cost hierarchy. The cost criteria at level 2 are cost of fuel, hardware cost, maintenance and service, auxiliary system, and environmental constraints. Fig. 3 presents the benefit hierarchy, it includes all possible benefits that may be derived from the various electrical power generation power plants, as applied to Jordan. Level 1 of Fig. 3 is the selection of the optimum system in terms of benefits. The benefit criteria at level 2 are the efficiency of the system, its reliability, its safety, availability of the fuel used in the system, its effect on national economy, and social benefits. The third level of the cost and benefit hierarchies represents the various technologies or alternatives which are going to be considered for electrical power production in Jordan. In addition to fossil fuel fired power plants these systems include nuclear, solar, wind, and hydro-power. 8. Results and discussion Fig. 2 shows that nuclear and fossil fuel power plants have the highest cost, with relative weights of 0.429 and 0.337, respectively. On the other hand solar, wind, and hydro have much lower values of relative weights in the range of 0.0770.079. It is based on the cost hierarchy which indicates that cost of fuel has the highest relative weight of 0.375 among all other costs considered. It is followed by hardware and maintenance costs; their relative weight is 0.215 each. Environmental constraints and the need of auxiliary system have the lowest relative weights with values of 0.122 and 0.074, respectively. Benefits hierarchy (Fig. 3) shows that fossil fuel power plant has the most benefits having a relative weight of 0.255. It is followed by solar and wind power plants; their corresponding relative weights are 0.162 and 0.130, respectively. Systems reliability has the highest relative weight of 0.365. It is followed by availability of fuel, systems efficiency, its effect on national economy, safety and then social benefits. In order to give the complete picture the overall cost priorities (relative weights) were divided by the benefit priorities. An overall normalized cost-tobenefit ratio was obtained for each system. They are presented in Fig. 4. It is shown that nuclear electrical power plants have the highest overall cost-to-benefit ratio, with a relative weighs value of 0.57. Fossil fuel power plants have the second relative weight of about 0.23. The best systems with lowest cost-to-benefit ratios are solar, followed by wind and then hydro having relative weights of 0.058, 0.061, and 0.083, respectively. 9. Conclusions Based on AHP, solar electrical power plants have the potential to be the best type of system for electricity production in Jordan. They are followed by wind and then hydro-power plants. One can argue that all three technologies or any of the two combined can be used since they have close relative weights. On the other hand nuclear power plants have the worst rating and fossil fuel power plants are some what little better than nuclear. 中文譯文 利用層次分析法選擇各類發(fā)電廠 摘要 本文運(yùn)用層次分析法 (AHP)詳細(xì)地介紹了利用不同能源進(jìn)行發(fā)電。這個(gè)理論認(rèn)為 ,除了化石燃料發(fā)電廠 ,還有核能、太陽能、風(fēng) 能、水電。結(jié)果表明 ,成本效益比較好的太陽能、風(fēng)能、水電可能是電力生產(chǎn)的最佳選擇。核能發(fā)電是最壞的選擇 ,緊隨其后的是化石燃料發(fā)電。 1.介紹 約旦是非石油生產(chǎn)的中東國家。它進(jìn)口的石油來自鄰近國家。大部分的電力來自國家不同的電力行業(yè) ,這些電廠使用化石燃料。這些燃料不是完全進(jìn)口的石油碳?xì)淙剂?,或部分地方 (只有很小的百分比 ,例如天然氣 )是碳?xì)淙剂稀?1996 年的電能消耗的價(jià)值達(dá)到了約 6000 美元 /年。他數(shù)量的 93%是由國家電力公司(NEPCO)供應(yīng)的 ,國家電力公司是在這個(gè)國家主要的電力供應(yīng)商。其他選擇的能源發(fā)電必須加以考慮。這些選項(xiàng)可以包括核能、太陽能、風(fēng)能、水電能源。約旦太陽能和風(fēng)能發(fā)電技術(shù)已在小規(guī)模實(shí)驗(yàn)。這些可再生能源的利用系統(tǒng)主要的偏遠(yuǎn)地區(qū) 。他們生產(chǎn)的電力被用來個(gè)人申請(qǐng)，如診所、照明、教育的電視機(jī)。這個(gè)偏遠(yuǎn)的村子位于約旦沙漠 ,是世界上最好的例子。所需的電能是完全由太陽能和風(fēng)能轉(zhuǎn)化系統(tǒng)提供。 在這篇文章中 ,除原油電廠，其他方案都被評(píng)估。提出了一個(gè)簡短的描述各種電站技術(shù)的方案，該方案包括核能、太陽能、風(fēng)力和水力。通過使用決策支持系統(tǒng)分析多重標(biāo)準(zhǔn) ,如層次分析法 (AHP),試圖協(xié)助決策者評(píng)估使用上述技術(shù) ,它在約旦可以是最適合電力生產(chǎn)的方案。 2.化石燃料發(fā)電 一般來說 ,化石燃料是不可再生的。他們來自地球的分解和化學(xué)轉(zhuǎn)化的有機(jī)材料。他們 有三類 :(1)固體 ,如煤和石油頁巖 ;(2)液體 ,如大多數(shù)石油化工產(chǎn)品。(3)氣體 ,例如天然氣。電力是最大的縮減燃料能源的代表。石油是一種化石燃料，在約但河中存在豐富。首先 ,就像所有的石油頁巖 ,它有一個(gè)較低的加熱價(jià)值。其次 ,約旦石油頁巖有硫磺含量 ,4-6%。由于石油的價(jià)格低，世界范圍內(nèi)的利用率高的化石燃料 ,如石油頁巖。因此 ,石油頁巖發(fā)電廠可以不被認(rèn)為是競爭的。在約旦除了小水電動(dòng)力發(fā)電，石油和天然氣是主要的發(fā)電燃料。 3.太陽能發(fā)電 自 20 世紀(jì) 70 年代，太陽能已經(jīng)在世界各地開始使用。許多國家把它作為解決環(huán)境污染和可能替代化石和核能的能源。因此 ,太陽能已經(jīng)作為生產(chǎn)電力的對(duì)象。許多研究和經(jīng)驗(yàn)表明，太陽能發(fā)電是電力行業(yè)中最經(jīng)濟(jì)發(fā)電形式。太陽能也能被轉(zhuǎn)換成電池 ,但是這個(gè)過程光伏電池是最方便的，但適用于小型應(yīng)用。獨(dú)立光伏電源系統(tǒng)提出了電氣化偏遠(yuǎn)地區(qū)的電力電網(wǎng)連接外供電系統(tǒng) 7。另一方面 ,太陽能量可以轉(zhuǎn)化熱能，利用太陽能集熱器或集中器等。如把太陽能轉(zhuǎn)換成熱能，然后變成機(jī)械能，再轉(zhuǎn)化為電能。大量的電力也可以產(chǎn)生電池。這個(gè)類型的接收器 ,能認(rèn)真考慮是 :(1)中心的接收器 ,(2)分布式接收器和 (3)太陽池。喬丹最喜歡享受中東國家漫長的陽光，當(dāng)?shù)氐奶鞖庖殉^ 300 萬里無云的日子。未來技術(shù)表明 ,死海本身可以作為 450 平方公里 ,2500 兆瓦電廠，運(yùn)行一個(gè)太陽能湖。最近的一份報(bào)告研究 ,死海可作為潛在利用的大型天然太陽池。從經(jīng)濟(jì)的角度講 ,發(fā)現(xiàn)的混合動(dòng)力塔只有太陽與同一領(lǐng)域的尺寸。有大量的太陽能熱發(fā)電廠在操作環(huán)游世界。他們發(fā)現(xiàn)是其中最經(jīng)濟(jì)系統(tǒng)是用于太陽能發(fā)電。這類系統(tǒng)很有吸引力的地方都是水邊遠(yuǎn)地區(qū)電網(wǎng)嚇人 ,不是可利用的。該系統(tǒng)能夠生產(chǎn) 30MW 電能或更多。 4.風(fēng)能發(fā)電 風(fēng)能非常好的一面在全球范圍內(nèi)廣泛存。對(duì)于不同的應(yīng)用程序 ,很明顯的是 ,風(fēng)能可以在許多位置有競爭優(yōu)勢(shì)。風(fēng)能可以應(yīng)用在許多場合 ,如抽水、海水淡化。它還可以用于發(fā)電用風(fēng)能量轉(zhuǎn)換系統(tǒng)。風(fēng)力發(fā)電有望成為二十一世紀(jì)新電子產(chǎn)生的最便宜的形式。 全球的化石燃料與相關(guān)的能量系統(tǒng)變得強(qiáng)硬 ,為減少排放的二氧化碳 ,風(fēng)系統(tǒng)的介紹可能顯著降低成本。例如 ,大型的風(fēng)力發(fā)電在風(fēng)網(wǎng)站利用新興技術(shù)能提供公用電網(wǎng)電在低價(jià)競爭關(guān)系 ,成為傳統(tǒng)發(fā)電。風(fēng)力發(fā)電廠可以用數(shù)以百計(jì)的風(fēng)力渦輪，范圍大小從 50 到 500 千瓦各座落在一些遙遠(yuǎn)的地區(qū)。工 廠的計(jì)算機(jī)控制中心設(shè)有類似的化石燃料植物 ,除了它不需要的渦輪機(jī)。最近的研究模式是定位算法風(fēng)力發(fā)電裝置。價(jià)格上漲的燃料和成本的化石燃料的依賴 ,在植物上的不可再生的能源資源 ,降低成本和價(jià)值的風(fēng)力發(fā)電系統(tǒng)明顯。 在約旦有潛在的高速度有數(shù)字的網(wǎng)站 ,可用于該目的。所提交的評(píng)估 ,風(fēng)能在約旦和其申請(qǐng)電力。風(fēng)地點(diǎn)被覆蓋了