Utilização do cavaco de madeira como combustível alternativo para a produção de vapor de água em uma caldeira aquatubular com grelha fixa do tipo PIN HOLE

The steady increase in the price of oil and its derivatives, carbon credits, the concern with the environment combined with the precipitation of rain water and lack of water resources that Brazil has suffered in 2014 caused a migration of participation sources of energy in the Brazilian energy matrix. The hydropower sector suffered big drop at 2013 and is suffering so far, contributing thus to the generation and cogeneration of thermal energy using renewable energy sources such as: sugarcane bagasse, wood chips, rice husks, among others. The selling price of the electricity market reached the level of R$ 807, 00 MWh in January 2014 (Source: ANEEL), heating the Brazilian thermoelectric sector. Although thermoelectric use in bulk water as vaporizing fluid to produce electricity and use in various processes, water reuse plans have become an important factor in these industries. The increased use of biomass has been the bagasse which is allied to the sugarcane sector, strong market in Brazil, and consists basically use the rest of sugar cane, sugarcane industries that would play out. The sugar and ethanol industry is very unstable and only lasts for 6-8 months a year, and the remaining time in the period known as between crop that corresponds to the planting and harvesting of sugarcane and then enter the period of vintage which is the constant cane harvesting and crushing it. This instability of the market and the thermoelectric idle period leads the thermoelectric industries to seek other sources of renewable energy, such as wood chips (pine, Eucalyptus, Orange), rice husk, sorghum among others, to not be dependent on alcohol sector. The present work aims to study the use of wood chips as an alternative biomass for burning a fuel that essentially uses bagasse, the thermoelectric in question consists of two boilers that produce together 350 t / h ... (Complete Abstract click electronic access below)

Aplicação da moderna teoria do Portfólio em ativos não financeiros

The Markowitz's objective functions, Value-at-Risk and Conditional Value-at-Risk, are largely used tools in the financial Market for portfolio optimization. This paper tries to analyze these functions having as a target to adapt them for application in non-financial assets portfolios. The paper uses as an example the Electricity Market to analyze and optimize a fictitious investment portfolio of a possible electric power utility. Showing that, besides being possible, which considerations must be taken and which analysis must be made to apply the Modern Portfolio Theory in the non-financial universe

Securities: Its Conception and Protection of Interests of its Holders

Theoretical studies of the problems of the securities markets in the Russian Federation incline to one or other of the two traditional approaches. The first consists of comparing the definition of "valuable paper" set forth in the current legislation of the Russian Federation, with the theoretical model of "Wertpapiere" elaborated by German scholars more than 90 years ago. The problem with this approach is, in Mr. Pentsov's opinion, that any new features of the definition of "security" that do not coincide with the theoretical model of "Wertpapiere" (such as valuable papers existing in non-material, electronic form) are claimed to be incorrect and removed from the current legislation of the Russian Federation. The second approach works on the basis of the differentiation between the Common Law concept of "security" and the Civil Law concept of "valuable paper". Mr. Pentsov's research, presented in an article written in English, uses both methodological tools and involves, firstly, a historical study of the origin and development of certain legal phenomena (securities) as they evolved in different countries, and secondly, a comparative, synchronic study of equivalent legal phenomena as they exist in different countries today. Employing the first method, Mr. Pentsov divided the historical development of the conception of "valuable paper" in Russia into five major stages. He found that, despite the existence of a relatively wide circulation of valuable papers, especially in the second half of the 19th century, Russian legislation before 1917 (the first stage) did not have a unified definition of valuable paper. The term was used, in both theoretical studies and legislation, but it covered a broad range of financial instruments such as stocks, bonds, government bonds, promissory notes, bills of exchange, etc. During the second stage, also, the legislation of the USSR did not have a unified definition of "valuable paper". After the end of the "new economic policy" (1922 - 1930) the stock exchanges and the securities markets in the USSR, with a very few exceptions, were abolished. And thus during the third stage (up to 1985), the use of valuable papers in practice was reduced to foreign economic relations (bills of exchange, stocks in enterprises outside the USSR) and to state bonds. Not surprisingly, there was still no unified definition of "valuable paper". After the beginning of Gorbachev's perestroika, a securities market began to re-appear in the USSR. However, the successful development of securities markets in the USSR was retarded by the absence of an appropriate regulatory framework. The first effort to improve the situation was the adoption of the Regulations on Valuable Papers, approved by resolution No. 590 of the Council of Ministers of the USSR, dated June 19, 1990. Section 1 of the Regulation contained the first statutory definition of "valuable paper" in the history of Russia. At the very beginning of the period of transition to a market economy, a number of acts contained different definitions of "valuable paper". This diversity clearly undermined the stability of the Russian securities market and did not achieve the goal of protecting the investor. The lack of unified criteria for the consideration of such non-standard financial instruments as "valuable papers" significantly contributed to the appearance of numerous fraudulent "pyramid" schemes that were outside of the regulatory scheme of Russia legislation. The situation was substantially improved by the adoption of the new Civil Code of the Russian Federation. According to Section 1 of Article 142 of the Civil Code, a valuable paper is a document that confirms, in compliance with an established form and mandatory requisites, certain material rights whose realisation or transfer are possible only in the process of its presentation. Finally, the recent Federal law No. 39 - FZ "On the Valuable Papers Market", dated April 22 1996, has also introduced the term "emission valuable papers". According to Article 2 of this Law, an "emission valuable paper" is any valuable paper, including non-documentary, that simultaneously has the following features: it fixes the composition of material and non-material rights that are subject to confirmation, cession and unconditional realisation in compliance with the form and procedure established by this federal law; it is placed by issues; and it has equal amount and time of realisation of rights within the same issue regardless of when the valuable paper was purchased. Thus the introduction of the conception of "emission valuable paper" became the starting point in the Russian federation's legislation for the differentiation between the legal regimes of "commercial papers" and "investment papers" similar to the Common Law approach. Moving now to the synchronic, comparative method of research, Mr. Pentsov notes that there are currently three major conceptions of "security" and, correspondingly, three approaches to its legal definition: the Common Law concept, the continental law concept, and the concept employed by Japanese Law. Mr. Pentsov proceeds to analyse the differences and similarities of all three, concluding that though the concept of "security" in the Common Law system substantially differs from that of "valuable paper" in the Continental Law system, nevertheless the two concepts are developing in similar directions. He predicts that in the foreseeable future the existing differences between these two concepts will become less and less significant. On the basis of his research, Mr. Pentsov arrived at the conclusion that the concept of "security" (and its equivalents) is not a static one. On the contrary, it is in the process of permanent evolution that reflects the introduction of new financial instruments onto the capital markets. He believes that the scope of the statutory definition of "security" plays an extremely important role in the protection of investors. While passing the Securities Act of 1933, the United States Congress determined that the best way to achieve the goal of protecting investors was to define the term "security" in sufficiently broad and general terms so as to include within the definition the many types of instruments that in the commercial world fall within the ordinary concept of "security' and to cover the countless and various devices used by those who seek to use the money of others on the promise of profits. On the other hand, the very limited scope of the current definition of "emission valuable paper" in the Federal Law of the Russian Federation entitled "On the Valuable Papers Market" does not allow the anti-fraud provisions of this law to be implemented in an efficient way. Consequently, there is no basis for the protection of investors. Mr. Pentsov proposes amendments which he believes would enable the Russian markets to become more efficient and attractive for both foreign and domestic investors.

U.S. utilities' experiences with the implementation of energy efficiency programs

In the U.S., many electric utility companies are offering demand-side management (DSM) programs to their customers as ways to save money and energy. However, it is challenging to compare these programs between utility companies throughout the U.S. because of the variability of state energy policies. For example, some states in the U.S. have deregulated electricity markets and others do not. In addition, utility companies within a state differ depending on ownership and size. This study examines 12 utilities’ experiences with DSM programs and compares the programs’ annual energy savings results that the selected utilities reported to the Energy Information Administration (EIA). The 2009 EIA data suggests that DSM program effectiveness is not significantly affected by electricity market deregulation or utility ownership. However, DSM programs seem to generally be more effective when administered by utilities located in states with energy savings requirements and DSM program mandates.

Case studies of the effects of a total solar eclipse on weather with varying degrees of cloud cover using a local numerical weather prediction model

The importance of renewable energies for the European electricity market is growing rapidly. This presents transmission grids and the power market in general with new challenges which stem from the higher spatiotemporal variability of power generation. This uncertainty is due to the fact that renewable power production results from weather phenomena, thus making it difficult to plan and control. We present a sensitivity study of a total solar eclipse in central Europe in March. The weather in Germany and Europe was modeled using the German Weather Service's local area models COSMO-DE and COSMO-EU, respectively (http://www.cosmo-model.org/). The simulations were performed with and without considering a solar eclipse for the following 3 situations: 1. An idealized, clear-sky situation for the entire model area (Europe, COSMO-EU) 2. A real weather situation with mostly cloudy skies (Germany, COSMO-DE) 3. A real weather situation with mostly clear skies (Germany, COSMO-DE) The data should help to evaluate the effects of a total solar eclipse on the weather in the planetary boundary layer. The results show that a total solar eclipse has significant effects particularly on the main variables for renewable energy production, such as solar irradiation and temperature near the ground.

Wind turbine wakes for wind energy

During recent years, wind energy has moved from an emerging technology to a nearly competitive technology. This fact, coupled with an increasing global focus on environmental concern and a political desire of a certain level of diversification in the energy supply, ensures wind energy an important role in the future electricity market. For this challenge to be met in a cost-efficient way, a substantial part of new wind turbine installations is foreseen to be erected in big onshore or offshore wind farms. This fact makes the production, loading and reliability of turbines operating under such conditions of particular interest.

Análisis técnico-económico de acceso al mercado alemán EPEX SPOT

Acciona Energía dispone en Alemania de 150 MW de potencia instalada. Todos ellos de energía eólica, en un total de doce parques eólicos situados en la sur del país. El proyecto tiene por objeto comparar las distintas modalidades de venta de energía procedente de fuentes renovables que ofrece el estado alemán para la cartera de activos de Acciona Energía, llegando a una conclusión final de cuál de ellas es la más aconsejable. Para ello se ha realizado un estudio del funcionamiento y normas del mercado Epex Spot de la electricidad y de la legislación alemana correspondiente a la materia, así como un seguimiento exhaustivo de producción y otras variables de los parques eólicos para su análisis. Los cálculos y las estimaciones realizados llevaron a la conclusión, que la mejor opción era la venta directa en el mercado Epex Spot, para lo que primero habría que darse de alta como agente en dicho mercado. Aunque esta opción asuma mayores riesgos también ofrecería un aumento considerable de ingresos. ABSTRACT Acciona Energía has 150 MW of power capacity in Germany, all of them wind energy in a total of twelve installations, located in the south of the country. The main goal of the project is to compare the different ways to sell the energy which became from renewable source that German state offers for Acciona’s asset portfolio, finding the most advisable conclusion. To do so a study of standards and rules of Epex Spot electricity market and German law related to this topic has been made. In addition of an exhaustive monitoring of energy production and others wind farms variables has been analyzed. The reckoning and estimations saw the conclusion that the best option was the direct sell in Epex Spot market, in order to do that the first of all is to register as market agent. Despite this options assume bigger risks, it provide a substantial increase in income

El papel de la hidroelectricidad en el contexto de las energías renovables en España

En el artículo se discute el papel de la energía hidroeléctrica en el marco del sistema eléctrico español, donde existe una elevada penetración de energías no gestionables con una tendencia clara a aumentar en los próximos años. El desarrollo de nuevas centrales hidroeléctricas se basará probablemente en centrales reversibles. La energía hidroeléctrica es una tecnología madura y eficiente para el almacenamiento de energía a gran escala y contribuye por tanto de manera decisiva a la integración de fuentes renovables no gestionables. Los beneficios obtenidos con la operación punta-valle pueden ser insuficientes para compensar el coste de una nueva central. Sin embargo, los ingresos obtenidos pueden incrementarse sustancialmente mediante su participación en los servicios de ajuste del sistema. Ello requeriría un diseño apropiado del mercado eléctrico. La contribución de las centrales hidráulicas reversibles al balance producción-consumo puede extenderse a las horas valle utilizando, bien bombeo en velocidad variable o bien una configuración de cortocircuito hidráulico. La necesidad de mitigar los efectos hidrológicos aguas abajo de las centrales hidroeléctricas puede introducir algunas restricciones en la operación que limitaría de algún modo los servicios descritos más arriba. Sin embargo, cabe esperar que los efectos ambientales provocados por las centrales hidráulicas reversibles sean significativamente menores. In this paper the role of hydropower in electric power systems is discussed, in the framework of the Spanish system, where a high penetration of intermittent power sources exists, showing a clear trend to increase in next years. The development of new hydro power facilities will be likely based on pumped storage hydro power plants. Hydropower is a mature and efficient technology for large-scale energy storage and therefore represents a key contribution for the integration of intermittent power sources, such as wind or photovoltaic. The benefits obtained from load shifting may be insufficient to compensate the costs of a new plant. However, the obtained revenues can significantly increase through its contribution to providing ancillary services. This would require an appropriate design of the electricity market. The contribution of pumped storage hydro power plants to balancing services can be extended to off-peak hours, using either variable speed pumping or the hydraulic shortcircuit configuration. The need to mitigate hydrological effects downstream of hydro plants may introduce some operational constraints which could limit to some extent the services described above. However environmental effects caused by pumped storage hydro power plants are expected to be significantly smaller.

Energy Transition in Europe’s Power House. Alleingang, avant-garde or blackout? IES Policy Brief Issue 2012/03/October 2012

Summary. The transformation of Germany’s energy sector will further exacerbate current network fluctuations and intensify the need for modifications in Europe’s power system. Cross-border power transfers will have to increase in order to overcome national limitations for absorbing large volumes of intermittent renewables like wind and solar power. In order to establish such an infrastructure on a European scale, the energy transition needs to be guided by an economic approach designed to prevent further fractures in the Internal Electricity Market. Moreover, constructive negotiations with neighbouring countries on market designs and price signals will be important preconditions for a successful energy transition in Europe.

A genetic estimation algorithm for parameters of stochastic ordinary differential equations

A generic method for the estimation of parameters for Stochastic Ordinary Differential Equations (SODEs) is introduced and developed. This algorithm, called the GePERs method, utilises a genetic optimisation algorithm to minimise a stochastic objective function based on the Kolmogorov-Smirnov statistic. Numerical simulations are utilised to form the KS statistic. Further, the examination of some of the factors that improve the precision of the estimates is conducted. This method is used to estimate parameters of diffusion equations and jump-diffusion equations. It is also applied to the problem of model selection for the Queensland electricity market. (C) 2003 Elsevier B.V. All rights reserved.

Power system sensitivity analysis for probabilistic small signal stability assessment in a deregulated environment

Deregulations and market practices in power industry have brought great challenges to the system planning area. In particular, they introduce a variety of uncertainties to system planning. New techniques are required to cope with such uncertainties. As a promising approach, probabilistic methods are attracting more and more attentions by system planners. In small signal stability analysis, generation control parameters play an important role in determining the stability margin. The objective of this paper is to investigate power system state matrix sensitivity characteristics with respect to system parameter uncertainties with analytical and numerical approaches and to identify those parameters have great impact on system eigenvalues, therefore, the system stability properties. Those identified parameter variations need to be investigated with priority. The results can be used to help Regional Transmission Organizations (RTOs) and Independent System Operators (ISOs) perform planning studies under the open access environment.

Transmission planning in a deregulated environment

The worldwide trend for the deregulation of the electricity generation and transmission industries has led to dramatic changes in system operation and planning procedures. The optimum approach to transmission-expansion planning in a deregulated environment is an open problem especially when the responsibilities of the organisations carrying out the planning work need to be addressed. To date there is a consensus that the system operator and network manager perform the expansion planning work in a centralised way. However, with an increasing input from the electricity market, the objectives, constraints and approaches toward transmission planning should be carefully designed to ensure system reliability as well as meeting the market requirements. A market-oriented approach for transmission planning in a deregulated environment is proposed. Case studies using the IEEE 14-bus system and the Australian national electricity market grid are performed. In addition, the proposed method is compared with a traditional planning method to further verify its effectiveness.

A real options based method for power system planning

A deregulated electricity market is characterized with uncertainties, with both long and short terms. As one of the major long term planning issues, the transmission expansion planning (TEP) is aiming at implementing reliable and secure network support to the market participants. The TEP covers two major issues: technical assessment and financial evaluations. Traditionally, the net present value (NPV) method is the most accepted for financial evaluations, it is simple to conduct and easy to understand. Nevertheless, TEP in a deregulated market needs a more dynamic approach to incorporate a project's management flexibility, or the managerial ability to adapt in response to unpredictable market developments. The real options approach (ROA) is introduced here, which has clear advantage on counting the future course of actions that investors may take, with understandable results in monetary terms. In the case study, a Nordic test system has been testified and several scenarios are given for network expansion planning. Both the technical assessment and financial evaluation have been conducted in the case study.

Power generation investment opportunities evaluation: A comparison between net present value and real options approach

To evaluate an investment project in the competitive electricity market, there are several key factors that affects the project's value: the present value that the project could bring to investor, the possible future course of actions that investor has and the project's management flexibility. The traditional net present value (NPV) criteria has the ability to capture the present value of the project's future cash flow, but it fails to assess the value brought by market uncertainty and management flexibility. By contrast with NPV, the real options approach (ROA) method has the advantage to combining the uncertainty and flexibility in evaluation process. In this paper, a framework for using ROA to evaluate the generation investment opportunity has been proposed. By given a detailed case study, the proposed framework is compared with NPV and showing a different results

Delay-sensitive service request scheduling for cloud computing

Cloud computing realizes the long-held dream of converting computing capability into a type of utility. It has the potential to fundamentally change the landscape of the IT industry and our way of life. However, as cloud computing expanding substantially in both scale and scope, ensuring its sustainable growth is a critical problem. Service providers have long been suffering from high operational costs. Especially the costs associated with the skyrocketing power consumption of large data centers. In the meantime, while efficient power/energy utilization is indispensable for the sustainable growth of cloud computing, service providers must also satisfy a user's quality of service (QoS) requirements. This problem becomes even more challenging considering the increasingly stringent power/energy and QoS constraints, as well as other factors such as the highly dynamic, heterogeneous, and distributed nature of the computing infrastructures, etc. ^ In this dissertation, we study the problem of delay-sensitive cloud service scheduling for the sustainable development of cloud computing. We first focus our research on the development of scheduling methods for delay-sensitive cloud services on a single server with the goal of maximizing a service provider's profit. We then extend our study to scheduling cloud services in distributed environments. In particular, we develop a queue-based model and derive efficient request dispatching and processing decisions in a multi-electricity-market environment to improve the profits for service providers. We next study a problem of multi-tier service scheduling. By carefully assigning sub deadlines to the service tiers, our approach can significantly improve resource usage efficiencies with statistically guaranteed QoS. Finally, we study the power conscious resource provision problem for service requests with different QoS requirements. By properly sharing computing resources among different requests, our method statistically guarantees all QoS requirements with a minimized number of powered-on servers and thus the power consumptions. The significance of our research is that it is one part of the integrated effort from both industry and academia to ensure the sustainable growth of cloud computing as it continues to evolve and change our society profoundly.^