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[en] This guide provides advice to the developers and operators of small distributed generation plant (including microgenerators) in the UK about the practical issues associated with connecting their plant and trading their output. Particular attention is given to sales revenues and how to access these revenue streams, including the mechanisms for purchasing Renewable Obligation Certificates (ROCs). The guide clarifies key terms, explains the wholesale trading system and provides an overview of sales opportunities (including ROCs and Levy Exemption Certificates (LECs)). Requirements on small distributed generation (including licensing, claiming class exemptions and metering) are described and the commercial aspects of connection (including the recent reduction in the barriers to connection) examined. Microgeneration (ie generators below 10 kW) issues are covered in their own chapter. The six appendices contain: background information about the industry; a list of purchasers of electricity from small distributed generators; descriptions of the generation, transmission and supply industries; information about industry standards and their governance; the role of government departments and institutions; and a glossary and other links
[en] 'Full text:' A long term solution to pollution and resource depletion problems requires addressing at least three issues: increasing the efficiency of energy conversion systems, optimizing the use of currently available energy sources and expanding the use of clean energy vectors. The use of fuel cells as energy vector for automobile and residential applications is promising alternatives for clean energy production. The aim of this work is to study interactions between the fuel cell stack, the uninterruptible power systems, and the control systems. The best strategies and topologies for optimal operation conditions of these systems for distributed power systems will also be determined. To reach this aim, three main points are being studied: development of a detailed dynamic fuel cell model for real-time operation conditions, where the main transient phenomena are modeled and analyzed; optimizing the control of the stack and the auxiliary components; and optimizing the interconnection of the fuel cell systems to the grid in order to protect the network from unwanted consequences of islanding. (author)
[en] Modern industrial plants are characterized by their large size and higher complexity of the processes involved in their operations.The real time monitoring systems of theses plants must be used a distributed architecture.Due to the pressure of competitive markets, an efficient adaptability to changes must be present in the plants.Modifications in the plants due to changes in the lay-out, the introduction of newer supervision, control and monitoring technologies must not affect the integrity of the systems.The aim of this work is give an introduction to the agent-based technology and analyze it advantage for the development of a modern monitoring system
[en] Distributed generation units are desirable from an environmental point of view but also have an impact on the costs of electricity grids at the distribution and transmission level. Therefore, investment planning has to consider all benefits and costs of DG to build DG sources at sites where they are economically efficient. Unfortunately, this is not an easy task in an unbundled industry where distribution and generation of electricity are not planned by one single institution. For this reason, this article analyses possible policy options for giving incentives to distributed generation and focuses on the long-term investment signals related to DG.
[en] Highlights: • A secondary flat reflector is added to commercial parabolic troughs. • Theoretical derivations and ray tracing used to size and position the absorber. • Concentration ratio increases up to 80% can be achieved for current collectors. • New flux distributions around the absorber are calculated. • The use of flat secondary reflector will increase the plant efficiency. - Abstract: Increasing the concentration ratio of parabolic troughs is one of the challenges to make this technology economically competitive against fossil fuels. Parabolic troughs with large concentration ratios face several problems such as difficulty capturing all the solar direct radiation and structural issues associated with thermal expansions and wind resistance amongst others. For larger mirrors it may be necessary to use a bigger absorber in order to capture all the radiation, thus increasing the thermal losses. A second stage reflector helps to increase the concentration ratio without increasing the primary mirror size. In this work, a theoretical analysis of a parabolic trough with a secondary flat reflector is developed and ray tracing is conducted in order to validate the equations obtained. A flat reflector will have a minimal economic impact in the cost of a parabolic trough and it allows larger concentration ratios for identical primary mirror areas compared to a standard parabolic trough. Increases of concentration ratio up to 80% are observed when a secondary flat reflector is inserted in a commercial system, while the shadow area introduced in the primary mirror is usually less than 15% of the primary mirror area. The increase in pumping power is offset by the increase in system efficiency.
[en] A literature review is conducted to understand the distributed generation, the reason for the introduction into modern power systems and other distributed generation technologies based on renewable energies that have been installed around the country. The frequency protections of distributed generation equipment under 1MW are studied according to international standards like IEEE-1547 and specifications of equipment manufacturers. The influence of the recommended international standards settings are investigated for systems of distributed generation, the performance in frequency that have presented under some frequency perturbation, as well as the influence that can have on the national and regional electrical system, with different amounts of technologies included in the national system. The recommended settings are evaluated through simulations in PSSE program in the context of the behavior of the frequency in the national electric system
[es]Una revision bibliografica es realizada para entender la generacion distribuida, la razon de la introduccion en los sistemas de potencia modernos y las distintas tecnologias de generacion distribuida a base de fuentes de energias renovables que se han instalado alrededor del pais. Las protecciones de frecuencia de los equipos de generacion distribuida menores de 1MW son estudiadas de acuerdo con estandares internacionales como IEEE-1547 y las especificaciones de los fabricantes de estos equipos. La influencia de los ajustes recomendados por las normas internacionales es investigada para los sistemas de generacion distribuida, el desempeno en frecuencia que han presentado bajo alguna perturbacion de frecuencia, asi como la influencia que pueden tener en el sistema electrico nacional y regional, con diferentes cantidades de las tecnologias incluidas en el sistema nacional. Los ajustes recomendados son valorados mediante simulaciones en el programa PSSE en el contexto del comportamiento de la frecuencia en el sistema electrico nacional
[en] This proceedings book contains the papers presented at 6th International Symposium on solar Thermal Concentrating Technologies held at Mojacar (Almeria) in September 28-October 2, 1992, The sessions were: 1.- Advanced components and systems: - Concentrators, - Volumetric and direct absorption receivers - Dish/Stirling 2.- Electricity Generation: - Central receiver systems - Distributed collector systems - Dish/Stirling systems - Economics - Potential for improvement 3.- Thermal/Chemical applications: - Chemical production - Detoxification of Hazardous waste and Solar desalination - Materials testing 4.- Long term research 5.- Test facilities
[en] This thesis focuses on direct solar resource in Reunion Island and numerical modeling of a solar power plant which is made up of: 1 / a field of linear Fresnel collectors using synthetic oil as heat transfer fluid; 2 / two sensible heat storage tanks; 3 / an organic Rankine cycle engine. The main goal is to evaluate the performance of such power plant in the island areas which were identified as suitable. To meet this goal, several studies have been conducted: (i) a direct normal solar radiation map of Reunion Island was built from satellite images of MeteoSat 7. This map was used to assess the availability of this resource; (ii) a new global-to-diffuse irradiance decomposition model was built from ground-based measurements performed at Saint-Pierre. This model is based on the highest probabilities of diffuse fraction occurrence; (iii) the geometry of the solar collector and direct normal solar irradiance were modeled from an existing ray-tracing code. This code has been used, firstly, to dimension the collector using an optimization method. And secondly, to develop a fast method to simulate absorbed flux distribution on the linear receiver components; (iv) unsteady-state heat transfers within the solar collector was modeled with a nodal approach; (v) annual electricity production of the power plant running in the south of the island was simulated with a control strategy relevant for the demand of the local electricity grid. The models that have been developed during this thesis are both tools for design support and the study of control strategies of solar power plants using linear Fresnel collectors. (author)
[fr]Cette these porte sur l'etude de la ressource solaire directe recue a La Reunion et sur la modelisation numerique d'une centrale solaire thermodynamique constituee: 1/d'un champ de capteurs lineaires de Fresnel dans lequel circule une huile de synthese; 2/de deux stocks de chaleur sensible; 3/ d'un cycle organique de Rankine. L'objectif est d'evaluer les performances d'une telle centrale fonctionnant dans une region de l'ile identifiee comme favorable. Pour repondre a cet objectif, plusieurs travaux ont ete menes: (i) une carte de l'ensoleillement direct normal recu en moyenne au cours d'une annee a ete realisee a partir des images du satellite MeteoSat 7 pour le territoire de la Reunion. Cette carte a permis d'evaluer la disponibilite de cette ressource; (ii) un nouveau modele de decomposition du rayonnement global en rayonnement diffus a ete developpe a partir de mesures effectuees a Saint-Pierre. Ce modele se base sur la representation des plus fortes probabilites d'occurrence de la fraction de diffus; (iii) la geometrie du capteur et le rayonnement direct qu'il concentre ont ete modelises a partir d'un code de lancer de rayons existant. Ce code a ete utilise, d'une part, pour dimensionner le capteur a l'aide d'une methode d'optimisation. Et d'autre part, pour mettre en place une methode de simulation 'rapide' des distributions de flux absorbe par les elements du recepteur lineaire a l'aide d'abaques; (iv) le comportement thermique du capteur solaire a ete modelise en dynamique avec une approche nodale; (v) le productible annuel d'une centrale fonctionnant dans le sud de l'ile a ete simule selon des procedures de regulation et de controle commande mise en place pour une strategie de production adaptee aux besoins de l'ile. Les modeles qui ont ete developpes durant cette these sont des outils d'aide au dimensionnement et permettent l'etude des strategies de controle commande d'une centrale solaire thermodynamique a capteur lineaire de Fresnel. (auteur)
[en] Research highlights: → Novel fuzzy pitch angle controller is proposed for smoothing wind fluctuation. → Storage batteries are used for performance improve of MG in islanding mode. → Those new techniques are compared with conventional PI pitch angle controller. -- Abstract: Power system deregulation, shortage of transmission capacities and needing to reduce green house gas have led to increase interesting in distributed generations (DGs) especially renewable sources. This study developed a complete model able to analysis and simulates in details the transient dynamic performance of the Micro-Grid (MG) during and subsequent islanding process. Wind speed fluctuations cause high fluctuations in output power of wind turbine which lead to fluctuations of frequency and voltages of the MG during the islanding mode. In this paper a new fuzzy logic pitch angle controller is proposed to smooth the output power of wind turbine to reduce MG frequency and voltage fluctuations during the islanding mode. The proposed fuzzy logic pitch controller is compared with the conventional PI pitch angle controller which usually used for wind turbine power control. Results proved the effectiveness of the proposed fuzzy controller in improvement of the MG performance. Also, this paper proposed using storage batteries technique to reduce the frequency deviation and fluctuations originated from wind power solar power fluctuations. Results indicate that the storage batteries technique is superior than fuzzy logic pitch controller in reducing frequency deviation, but with more expensive than the fuzzy controller. All models and controllers are built using Matlab (registered) Simulink (registered) environment.
[en] An analysis of solar panels technologies is realized to implement an application of distributed generation in vehicle parking. The different technologies available in the market about solar panels are investigated. The climatological and geographical conditions are studied for the use of solar energy. The electrical requirements are determined for the implementation of solar panels as a distributed generation system. The benefit/cost is analyzed in establishments of vehicle parking for the implementation of solar panels. A photovoltaic system was developed in a vehicle parking attached at the Colegio Federado de Ingenieros y Arquitectos, and also the technical feasibility has been determined. The photovoltaic systems about roofs of buildings every day have been more viable, due that the cost of the systems has been lower and more efficient. Crystalline silicon ''mono'' or ''poly'' has been the most reliable option in the development of new technologies in solar cells. Costa Rica is found in a zone where the photovoltaic solar energy is harnessed and should to be fostered by the engineering sector. The installation of photovoltaic systems has contributed to reduce the carbon footprint in the distributed generation
[es]Un analisis de las tecnologias de paneles solares es realizado para la implementacion de una aplicacion de generacion distribuida en estacionamientos de vehiculos. Las diferentes tecnologias existentes en el mercado sobre paneles solares son investigadas. Las condiciones climatologicas y geograficas de Costa Rica son estudiadas para el aprovechamiento de la energia solar. Los requerimientos electricos son determinados para la implementacion de paneles solares como un sistema de generacion distribuida. El beneficio/costo es analizado en establecimientos de parqueo de vehiculos para la implementacion de paneles solares. Un sistema fotovoltaico fue desarrollado en un estacionamiento de vehiculos adjunto al Colegio Federado de Ingenieros y Arquitectos, y ademas la viabilidad tecnica ha sido determinada. Los sistemas fotovoltaicos sobre techos de edificaciones cada dia han sido mas viables, debido que el costo de los sistemas ha sido menor y mas eficiente. El silicio ''mono'' o ''poli'' cristalino ha sido la opcion mas confiable en el desarrollo de nuevas tecnologias en las celdas solares. Costa Rica es encontrada en una zona donde la energia solar fotovoltaica es aprovechada y debe ser fomentada por el sector ingenieril. La instalacion de sistemas fotovoltaicos ha contribuido a reducir la huella de carbono en la generacion distribuida