Cyprus energy system and the use of renewable energy sources

Cyprus is an island state whose energy production is almost completely dependent on imported hydrocarbon fuels. Its electricity production sector is more than 90% dependent on oil products while the remaining 9% are covered by imports of coal (4.5%) and by solar energy (4.5%). Because Cyprus will become a full member of the European Union (EU), it becomes essential to follow the EU white paper rules and insert renewable energy sources (RES) as part of its energy production system. Solar, wind energy and biomass are the three available forms of RES. This paper will examine and analyze the energy system of Cyprus. It will examine the RES available and the extent of the energy needs could be satisfied by them.     

Development of an integrated data-acquisition system for renewable energy sources systems monitoring

Data-acquisition systems are widely used in renewable energy source (RES) applications in order to collect data regarding the installed system performance, for evaluation purposes. In this paper, the development of a computer-based system for RES systems monitoring is described. The proposed system consists of a set of sensors for measuring both meteorological (e.g. temperature, humidity etc.) and electrical parameters (photovoltaics voltage and current etc.). The collected data are first conditioned using precision electronic circuits and then interfaced to a PC using a data-acquisition card. The LABVIEW program is used to further process, display and store the collected data in the PC disk. The proposed architecture permits the rapid system development and has the advantage of flexibility in the case of changes, while it can be easily extended for controlling the RES system operation.     

Central Asian countries energy system and role of renewable energy sources

The status, problems, and development prospects of the fuel and energy complex of the Central Asian Region (CAR) countries are examined. In particular, data are presented on the CAR energy system resource base, and production and consumption of the fuel and energy resources in the CAR countries are analyzed. Special attention is devoted to the use of renewable energy sources.     

Integrating renewable sources of energy into an existing combined heat and power system

In recent years, renewable energy sources have played an increasingly important role in potential energy production. The integration of renewables into energy production plants has therefore become a major challenge for many organizations. This study concerns the modernization of a small power plant in a large hospital. The design criteria include the possibility of utilizing renewable energy sources and providing a potential increase in heat production (with additional heat being supplied to a nearby university campus). The existing boiler conditions (i.e. controls, efficiency, etc.) are unable to satisfy the desired requirements and therefore require an extensive retrofit.     

西藏可再生能源详考

西藏自治区是我国的西南屏障，具有十分重要的战略地位。最近几年，随着改革开放的进一步深入和西部大开发的全面实施，西藏正在逐步加大对外开放的力度，以吸引更多的投资和建设项目。但是，由于西藏的地理条件和自然条件的限制，交通和电力等基础设施的相对落后，已经成为制约西藏发展的瓶颈。我国政府投入了大量的财力和物力发展可再生能源，现正在西部部分省份实施利用可再生能源发电解决无电乡镇的用电问题，即“光明工程”。其中西藏自治区是“光明工程”的重中之重。为了更为有效地在西藏自治区发展和利用太阳能，解决电网无法覆盖地…     

Exergy analysis of renewable energy sources

Oil crises in the past years made more obvious the dependency of economies on fossil fuels. As a consequence, the need for new energy sources became more urgent. Renewable energy sources could provide a solution to the problem, as they are inexhaustible and have less adverse impacts on the environment than fossil fuels. Yet, renewable energy sources technology has not reached a high standard at which it can be considered competitive to fossil fuels. The present study deals with the exergy analysis of solar energy, wind power and geothermal energy. That is, the actual use of energy from the existing available energy is discussed. In addition, renewable energy sources are compared with the non-renewable energy sources on the basis of efficiency.     

Design of an energy hub based on natural gas and renewable energy sources

This paper presents a simulation model for an energy hub consisting of natural gas (NG) turbines as the main sources of energy (including both electricity and heat) and two renewable energy sources—wind turbines (WTs) and photovoltaic (PV) solar cells. The hub also includes water electrolyzers for hydrogen production. The hydrogen serves as an energy storage medium that can be used in some transportation applications, or it can be mixed with the NG feed stream to improve the emission profile of the gas‐turbine unit. The capacity of the designed hub is meant to simulate and replace the coal‐fired Nanticoke Generating Station with a NG‐fired power plant. Therefore, the aim of this work is to develop a simulated model that combines different energy generation technologies, which are evaluated in terms of the total energy produced, the cost per kWh of energy generated, and the amount of emissions produced. The proposed model investigates the benefits, both economic and environmental, the technological barriers, and the challenges of energy hubs by developing several scenarios. The simulation of these scenarios was done using General Algebraic Modeling System (GAMS®). Although the software is strongly known for its optimization capability, the mixed complementary problems solver makes it a strong tool for solving equilibrium problems. Excess energy produced during off‐peak demand by WTs and PV solar cells was used to feed the electrolyzer to produce H₂ and O₂. The proposed approach shows that a significant reduction in energy cost and greenhouse gas emissions were achieved, in addition to the increased overall efficiency of the energy hub. Out of the examined three scenarios, Scenario C appeared to be the most feasible option for a combination of renewable and non‐renewable technologies as it did not only produce hydrogen, but also provided electricity at relatively lower prices. Copyright © 2013 John Wiley & Sons, Ltd.     

Economic curtailment of intermittent renewable energy sources

In a power system featuring a large share of intermittent renewables and inflexible thermal generators, efficiency gains could be achieved by curtailing the production of renewables. However, as renewables feature very low variable production costs, over-curtailment can be costly. In this article, we use a stylised analytical model to assess this trade-off. We show that while curtailing renewables when their variability is high and the system flexibility is low can reduce generation costs, the different stakeholders will not necessarily benefit from such measures. As a consequence, leaving this decision to generators will lead to a sub-optimal level of curtailment. Either incentives to provide accurate RES availability forecasts or alternatively centralised forecasting should be put into place to solve the resulting problem of asymmetry of information.     

国际可再生能源会议信息

2004/1/17-21欧洲可再生能源学术讨论会会议地点:德国柏林联系人:Eufores,EuropeanForumforRenew-ableEnergySources,RenewableEnergyHouse,26RuedeTrone,B-1000Brussels,Belgium.电话:+3225461948传真:+3225461934电子邮件:eufores@eufores.org网址:www.eufores.org2004/1/19-21欧洲可再生能源讨论会会议地点:德国柏林联系人:ChristineLins,SecretaryGeneral,EREC,EuropeanEenewableEnergyCouncil,26,RueduTrone,B-1000Brussels,Belgium电话:+3225461933传真:+3225461934电子邮件:berlin2004@erec-renewables.org网址:www.ere…     

新能源和可再生能源的分类

新能源和可再生能源的概念和含义,是1981年联合国在内罗华召开的新能源和可再生能源会议上确定的,它不同于常规化石能源,可以持续发展,几乎是用之不竭,对环境无多大损害,有利于生态良性循环。目前,联合国开发计划署(UNDP)将新能源和可再生能源分为3类:(1)大中型水电;(2)新可再生能源,包括小水电、太阳能、风能、现代生物质能、地热、海洋能;(3)传统生物质能。在我国,新能源和可再生能源是指除常规化石能源和大中型水力发电、核裂变发电之外的生物质能、太阳能、风能、小水电、地热能以及海洋能等。这些能源,资源丰富,可以再生,清洁干净,是…     

Technological model of micro power facilities based on renewable energy sources with the energy storage

The problems concerning the combined use of micro power facilities with and without hydroelectric storage are discussed. The data that illustrate the cost-effectiveness of their operation depending on the load chart of the users are presented.     

Electricity generation from renewable energy sources in Poland

AbstractFor the European Union's Member States 2001/77/EC Directive on the promotion of electricity produced from renewable energy sources in the internal electricity market determined targets for 2010 of 21% share of electricity from renewable energy sources in total electricity consumption. Particular Member States adopted different measures for development of renewable and in consequence they achieved different results. Poland, being Member State of the EU since 2004 has accepted target of 7.5% for electricity generated from renewable energy sources until 2010. Currently, in this decade, new 2009/28/EC Directive on the promotion of the use of energy from renewable sources plays significant role in development of renewable energy sources. Directive set new target for 2020. Nowadays is a time for summary and assessment of results fulfilling Directives and monitor progress of new targets. Article presents measures implemented for renewable source energy development, also current state and perspectives of using of renewable energy sources in Poland and in the EU.     

Energy-based system well-being analysis for small systems with intermittent renewable energy sources

One of the fundamental requirements of a power system, especially in a small isolated power system (SIPS), is secure and reliable energy supply. In this paper, a novel Energy-Based System Well-being Analysis framework (EBSWBA) is presented to assess the reliability of systems containing renewable energy sources (RES), fossil-fueled sources and electricity storage. The framework combines the advantages of the well-known System Well-being Analysis (SWBA) and Expected Energy Not-Served (EENS) approaches, thus overcoming the weaknesses of the SWBA by considering all key factors that influence the system adequacy. Furthermore, two techniques are proposed for calculation of the EBSWBA indices: the Monte-Carlo Simulation (MCS) adopted for the EBSWBA framework, and the Contingency Enumeration for Small Isolated Power Systems (CESIPS) technique, which is derived from the Contingency Enumeration (CE) methodology. These techniques enable formation of probability distributions of the indices. The comparison of the results of classical SWBA and EBSWBA when applied to different SIPS architectures, operating schemes and load profiles demonstrates the superiority of EBSWBA over SWBA in terms of rendered information about the system state as well as in terms of computational efficiency, especially when the CESIPS technique is used for calculation of the EBSWBA indices.     

Potential and use of renewable energy sources in Croatia

The current share of renewable energy sources in electricity production in Croatia is very high, around 50%. Nevertheless it is expected that the share of renewables will have to rise and efficient strategies must be examined and adopted. The Croatian government has recognised the important role renewable energy sources could play in Croatian energy and electricity supply. The most important barrier for a wider deployment of renewables in energy production is their cost which is still above those of conventional energy sources. As the energy market is currently undergoing the process of liberalisation, support mechanisms that are compatible with an open market philosophy must be adopted. The characteristics of the Croatian power system, the expected consumption, growth and possible future role of renewables in energy and electricity production is presented. The current legislative framework relevant for renewables is analysed and discussed.     

Assessing the potential of renewable energy sources in Turkey

To meet Turkey’s growing energy demand, the installed electric power capacity of 27.8 GW in 2001 has to be doubled by 2010 and increased fourfold by 2020. The difference between Turkey’s total primary energy supply (TPES) of from its own sources and total final consumption (TFC) is projected grow from 1 quad (1.06–2.06) in 1999 to 5.71 quads (2.79–8.5) in 2020 (1 QUAD=293.071 TWh). Turkey’s limited amount of fossil fuels has a present average ratio of proved reserves of 97.38 quads to production rate of 3.2 quads yr⁻¹ of about 30 years. Turkey’s reliance on fossil fuel-based energy systems to meet the growing demand is most likely to exacerbate the issues of energy insecurity, national environmental degradation, and global climate change in increasing proportions. Economically-feasible renewable energy potential in Turkey is estimated at a total of ca. 1.69 quads yr⁻¹ (495.4 TWh yr⁻¹) with the potential for 0.67 quads yr⁻¹ (196.7 TWh yr⁻¹) of biomass energy, 0.42 quads yr⁻¹ (124 TWh yr⁻¹) of hydropower, 0.35 quads yr⁻¹ (102.3 TWh yr⁻¹) of solar energy, 0.17 quads yr⁻¹ (50 TWh yr⁻¹) of wind energy, and 0.08 quads yr⁻¹ (22.4 TWh yr⁻¹) of geothermal energy. Pursuit and implementation of sustainability-based energy policy could provide about 90 and 35% of Turkey’s total energy supply and consumption projected in 2010, respectively. Utilization of renewable energy technologies for electricity generation would necessitate about 23.2 Mha (29.8%) of Turkey’s land resources.     

Identifying barriers in the diffusion of renewable energy sources

Rapid diffusion of renewable energy sources (RES) in the electricity power sector is crucial if the EU wants to fulfill its 2050 CO₂ reduction commitments. For this reason, identifying and alleviating all barriers that hinder the development of RES is necessary to the successful deployment of these technologies. This paper discusses the main barriers in the diffusion of wind and photovoltaic (PV) solar power in the Greek electricity sector by drawing on the literature of technological innovation systems and system functions. Furthermore, we provide an explanation of the different diffusion rates between the two technologies. Inadequate financial resources, low grid capacity, delays in the issuance of building permits, opposition from local communities to the construction of wind farms and the lack of a stable institutional framework are among the most important barriers that inhibit the diffusion of the wind and PV solar power. The nature of the barriers identified in this study calls for policy intervention.     

Sustainable application of renewable sources in water pumping systems: Optimized energy system configuration

Eighteen years ago, in Portugal, the expenses in a water supply system associated with energy consumption were quite low. However, with the successive crises of energy fuel and the increase of the energy tariff as well as the water demand, the energy consumption is becoming a larger and a more important part of the total budget of water supply pumping systems. Also, new governmental policies, essentially in developed countries, are trying to implement renewable energies. For these reasons, a case-study in Portugal of a water pumping system was analysed to operate connected to solar and wind energy sources.     

The rôle of renewable energy sources in the Italian agricultural system

Italy imports more than 83 per cent of its primary energy. In particular, the Italian agricultural sector imports 100 per cent of its primary energy needs. Today, an effort is being made towards a better mix of primary sources and towards reducing the country's dependence on imports, especially in this sector where there are considerable endogenous energy sources. Solar thermal energy and energy from biomass can be substituted for oil. The present paper analyses the end uses of energy in Italian agriculture and assesses the amount which can be substituted by solar thermal and biogas technologies. For each end use category, the benefits of renewable technologies are compared with the economics of non-renewable sources. The results of the analyses show that the most competitive technologies are biogas systems, passive solar systems (especially solar greenhouses) and energy-saving measures. Active solar systems are close to the threshold of competitiveness for low temperature heating, so that their penetration is very dependent on fuel prices and on the politics of financial subsidies.     

微藻生物质可再生能源的开发利用

藻类具有生物量大、生长周期短、易培养以及含有较高的脂类等特点，是制备生物质液体燃料的良好材料。微藻热解所得的生物质燃油热值高达33MJ/kg，是木材或农作物秸秆的1．6倍。通过调节微藻的培养条件和脂类含量，可获得高品质、高热值的生物质燃油。