On the testing of large PV arrays

This paper reports on the IES-UPM experience from 2006 to 2010 in the field of the characterization of PV arrays of commercial large PV plants installed in Spain within the framework of the profitable economic scenarios associated to feed-in tariff laws. This experience has extended to 200 MW and has provided valuable lessons to minimize uncertainty, which plays a key role in quality assurance procedures. The paper deals not only with classic I–V measurements but also with watt-metering-based procedures. Particular attention is paid to the selection of irradiance and cell temperature sensors

Estudio de viabilidad para instalar una planta de cogeneración

En el presente proyecto se estudia la viabilidad, tanto técnica como económica, de la instalación de una planta de cogeneración, en una industria alimentaria en Aldaya (Valencia). El diseño de la central de cogeneración se basa en la demanda energética de la fábrica, atendiendo a los requisitos necesarios para acogerse al Régimen Especial de producción de energía eléctrica establecidos en el Real Decreto 661/2007, de 25 de mayo. En cuanto a la viabilidad económica, se ha elegido la alternativa de venta de electricidad a la red a tarifa, (a un precio fijo y regulado) con el fin de asegurar los ingresos en el estudio económico y reducir la sensibilidad del proyecto a las variables del mercado. Como resultado se obtienen la reducción de los costes de energía de la fábrica, mejora de la fiabilidad de suministro, reducción de emisiones globales de CO2, y una elevada rentabilidad del proyecto. ABSTRACT The aim of this project is to study the technical and economic feasibility of a cogeneration plant in a food industry in Aldaya (Valencia). The design of the cogeneration plant is based on the energetic demand of the factory, attending to the requirements specified in the Special Regime of production of electric power established in the R.D. 661/2007. The studied alternative in terms of economic viability is selling electricity to the net by tariff, which is a fixed and regulated price in order to assure the revenue in the economic study and to reduce the project sensitivity to the market variation. The results obtained are: reduction in energy costs of the fabric, improvement of reliability in the electrical supply, reduction of global CO2 emission, and high profitability of the project.

The first renewable forward market mechanisms in the Iberian Electricity Market

A description of the first renewable forward market mechanisms in the Iberian Electricity Market is provided. A contract for difference mechanism is available in Spain since March 2011between the last resort suppliers and the special regime (renewables and cogeneration) settling the price differences between the equilibrium price of the forward regulated auctions for the last resort supply and the spot price of the corresponding delivery period. Regulated auctions of baseload futures of the Portuguese zone in which the Portuguese last resort supplier sells the special regime production exist since December 2011. The experience gained from renewables auctions in Latin America could be used in the Iberian Electricity market, complementing these first market mechanisms. Introduction of renewable auctions at least for the most mature technologies (i.e. wind) in Spain and Portugal providing a fair price for the renewable generation will be of utmost importance in the short term to diminish the tariff deficit caused by the massive deployment of the feed-in-tariff scheme. Liquidity in the forward markets will also increase as a result of the entry of renewable generation companies intending to maximize their profits due to gradual suppression of feed in tariff schemes.

Renewable energies Driven by Feed-on Tariffs. Photovoltaic vs Wind Energy Development in Spain

Although others regulations regarding feed-in tariffs for photovoltaics (PV) existed in Spain previously, the one that meant a paradigm change was the introduction in 2007 of law R.D.661/2007 which established a feed-in tariff of 41,75 cents/kWh if the installed capacity was greater than 100KWp and 44,04 cents/kWh if it was smaller. The high level of the subsidies together with the lack of a limit for the total installed capacity originates the well-known Spanish photovoltaic boom. In September 2008 the installed PV capacity accounted for 3.2GWp (while the official objective stated in the national renewable roadmap was only 400MWp). To avoid this situation a new law, R.D. 1578/2008, was proclaimed which established a decreasing feed-in tariff of 32 cents/kWh (for ground installations) and 34 cents/kWh (for rooftops) and it limited the annual installed capacity to 500MWp. Although it was successful in limiting the PV subsidies total costs, the successive and sudden changes in regulations resulted very harmful to the local PV industry. In this article, the strong influence of feed-in tariff in the development of PV installed capacity and market evolution in Spain will be analyzed in detail. In addition, a comparison with other subsidized technologies which installed capacity has had a smoother evolution, as wind energy, will be presented.

Diffusion of photovoltaic in Germany: policy vs. consumers

In some countries photovoltaic (PV) technology has already achieved a stage of development at which it can compete with conventional electricity sources. Germany provides a good illustration of this where PV market has reached a mature stage. As a manifest of this, the German government has recently reduced subsidies for households and industry by decreasing the feed in tariff for PV. This development raises fundamental questions: could the PV industry survive? Will consumers be motivated to continue to adopt PV when feed-in tariff diminish? The point of departure for the relevant literature on diffusion of PV has been on the effect of subsidies but little attention has paid to consumer motives when the policy support is scaled down. This paper introduces an in-depth analysis on understanding the consumer motives for adopting photovoltaic applications. Anchored in an extensive exploratory case study on PV consumers and PV system providers, this study aims to provide an encompassing explanation of diffusion of PV by revealing the link between consumer motives and the impact of policy.

Performance of UV-enhanced PMMA fresnel lenses and impact on LCOE

Tiny increases in the transmittance of optical materials within a CPV module can have an important impact on the economy of a plant. This is certainly true in systems comprising multi-junction solar cells, whose high performance, based on a balanced photocurrent generation among the series-connected junctions, is very sensitive to spectrum variations. Every efficiency point gained causes not only an increase in the kilowatts hour produced, but a higher benefit on it, since the difference between electricity tariff and Levelized Cost of Electricity (LCOE) rises. This work studies the impact on the LCOE of a plant based on modules comprising PMMA lenses of two different types, standard UV blocking grade which is normally used for outdoor applications at high DNI climate and a specialty stabilized UV-enhanced transmittance acrylic (see Figure 1). Energy production will be compared for these two systems throughout the year at different sites to analyze when (season, time of the day) and where the usage of the enhanced PMMA is justified.

Diffusion of photovoltaic in Germany: roles of policy, system suppliers and adopters

In some countries photovoltaic (PV) technology is at a stage of development at which it can compete with conventional electricity sources. A case in point is Germany where PV market has reached a mature stage. As a manifest of this, the German government has recently reduced the feed-in-tariff, which had been the strongest driver of PV diffusion. This development raises a fundamental question: Why would potential adopters be motivated to adopt PV when feed-in tariff diminishes? The point of departure for the literature on diffusion of PV has been on the effect of subsidies but little attention has paid to adopter motives when the policy support is scaled down. This paper presents an in-depth analysis of the adopter motives for photovoltaic applications. Anchored in an extensive exploratory case study we provide an encompassing explanation of roles of policy, adopters and system suppliers on diffusion of PV.

Sistema para el análisis del consumo eléctrico y optimización en la contratación del suministro

El presente trabajo se enmarca en el ámbito de la eficiencia energética y contempla la gestión del consumo eléctrico en hogares. Concretamente, para este proyecto fin de grado se propone el desarrollo de un sistema informático que permita el análisis y monitorización del consumo eléctrico y optimización en la contratación del suministro eléctrico en el hogar. El sistema desarrollado permite la monitorización del consumo eléctrico, expresado en kilovatios-hora (kWh), y la monitorización del coste real de dicho consumo, expresado en euros, en función del tipo de tarifa que se tenga contratada en la modalidad del PVPC1 (Precio Voluntario para el Pequeño Consumidor). También se ha desarrollado una interfaz web a través de la cual el usuario tiene acceso a la información y datos del sistema. En dicha web se muestran gráficas de consumo, potencia, voltaje, corriente y coste de la energía por días. Además, se ha dotado al sistema de un generador de alertas que notifica al usuario, vía web y vía correo electrónico, cuando el consumo sobrepasa los límites fijados por él mismo. El usuario, por tanto, podrá definir los valores de alerta de sobreconsumo y visualizar tanto un histórico de las alertas generadas en el pasado como las alertas activas en ese momento. Las alertas se muestran en la gráfica correspondiente dentro de la aplicación web. Por último, se dispone de la opción de exportar las gráficas que son visualizadas en la aplicación web en formato PNG, JPEG, PDF y SVG, además de la posibilidad de imprimirla.---ABSTRACT---This project belongs to the Energy Efficiency field and is aimed at home energy management. Specifically, for this thesis the development of a computer system that allows monitoring and analysis of energy consumption and contracted power optimization is proposed. The developed system allows energy consumption management within households (expressed in kilowatts per hour, kWh) and real cost monitoring (in euros) according to the contract tariff. A web interface has been developed in order to provide the user with power consumption information and control energy tools. In this web application, electric consumption, power, voltage, current and energy cost by day are shown. Besides, an alert generation system has been implemented so that the user can define maximum power consumption values and be informed through email or web when these values are exceeded. The user will be able to check older power alerts as well as the currently active ones. These alerts are shown in a specific graph within the web application. Finally, the user generated graphs can be exported from the web using PNG, JPEG, PDF or SVG image formats as well as be printed from the web.