Inorganic Photovoltaics - Planar and Nanostructured Devices

Since its invention in the 1950s, semiconductor solar cell technology has evolved in great leaps and bounds. Solar power is now being considered as a serious leading contender for replacing fossil fuel based power generation. This article reviews the evolution and current state, and potential areas of near future research focus, of leading inorganic materials based solar cells, including bulk crystalline, amorphous thin-films, and nanomaterials based solar cells. Bulk crystalline silicon solar cells continue to dominate the solar power market, and continued efforts at device fabrication improvements, and device topology advancements are discussed. III-V compound semiconductor materials on c-Si for solar power generation are also reviewed. Developments in thin-film based solar cells are reviewed, with a focus on amorphous silicon, copper zinc tin sulfide, cadmium telluride, as well as nanostructured Cadmium telluride. Recent developments in the use of nano-materials for solar power generation, including silicon and gallium arsenide nanowires, are also reviewed.

Trois essais sur les banques et le pouvoir de marché

Cette thèse examine le rôle du pouvoir de marché dans le marché bancaire. L’emphase est mis sur la prise de risque, les économies d’échelle, l’efficacité économique du marché et la transmission des chocs. Le premier chapitre présente un modèle d’équilibre général dynamique stochastique en économie ouverte comprenant un marché bancaire en concurrence monopolistique. Suivant l’hypothèse de Krugman (1979, 1980) sur la relation entre les économies d’échelle et les exportations, les banques doivent défrayer un coût de transaction pour échanger à l’étranger qui diminue à mesure que le volume de leurs activités locales augmente. Cela incite les banques à réduire leur marge locale afin de profiter davantage du marché extérieur. Le modèle est solutionné et simulé pour divers degrés de concentration dans le marché bancaire. Les résultats obtenus indiquent que deux forces contraires, les économies d’échelle et le pouvoir de marché, s’affrontent lorsque le marché se concentre. La concentration permet aussi aux banques d’accroître leurs activités étrangères, ce qui les rend en contrepartie plus vulnérables aux chocs extérieurs. Le deuxième chapitre élabore un cadre de travail semblable, mais à l’intérieur duquel les banques font face à un risque de crédit. Celui-ci est partiellement assuré par un collatéral fourni par les entrepreneurs et peut être limité à l’aide d’un effort financier. Le modèle est solutionné et simulé pour divers degrés de concentration dans le marché bancaire. Les résultats montrent qu’un plus grand pouvoir de marché réduit la taille du marché financier et de la production à l’état stationnaire, mais incite les banques à prendre moins de risques. De plus, les économies dont le marché bancaire est fortement concentré sont moins sensibles à certains chocs puisque les marges plus élevés donnent initialement de la marge de manoeuvre aux banques en cas de chocs négatifs. Cet effet modérateur est éliminé lorsqu’il est possible pour les banques d’entrer et de sortir librement du marché. Une autre extension avec économies d’échelle montre que sous certaines conditions, un marché moyennement concentré est optimal pour l’économie. Le troisième chapitre utilise un modèle en analyse de portefeuille de type Moyenne-Variance afin de représenter une banque détenant du pouvoir de marché. Le rendement des dépôts et des actifs peut varier selon la quantité échangée, ce qui modifie le choix de portefeuille de la banque. Celle-ci tend à choisir un portefeuille dont la variance est plus faible lorsqu’elle est en mesure d’obtenir un rendement plus élevé sur un actif. Le pouvoir de marché sur les dépôts amène un résultat sembable pour un pouvoir de marché modéré, mais la variance finit par augmenter une fois un certain niveau atteint. Les résultats sont robustes pour différentes fonctions de demandes.

Propuesta metodológica para la renovación de los sistemas y procesos de administración de los mercados eléctricos: el caso colombiano

El mercado eléctrico ha evolucionado en Colombia desde 1995, fortaleciéndose institucionalmente, dinamizando su desarrollo, y enfrentando grandes desafíos. Los sistemas de administración, que soportan el funcionamiento del mercado, han evolucionado a la par, aunque algunos se encuentran aislados entre sí o han sido desarrollados en plataformas diferentes, lo que dificulta la sostenibilidad y el mantenimiento, y reducen la facilidad de incorporar cambios. Al referenciarse con otros mercados en el mundo, se observa gran dinámica en la incorporación de tecnologías en información y comunicaciones, avances regulatorios o requerimientos de clientes. Se requiere una renovación tecnológica que conserve el conocimiento adquirido, y permita incorporar fácilmente las tendencias del mercado. Este artículo presenta los resultados de la propuesta metodológica para la renovación tecnológica enmarcada en el proyecto Colciencias CNBT 833559938649 de investigación tecnológica, Sistema para la administración del mercado de energía eléctrica en Colombia, Fase I.

Testing for Market Power in Multiple-Input, Multiple-Output Industries: The Australian Grains and Oilseeds Industries

Recent empirical studies have found significant evidence of departures from competition in the input side of the Australian bread, breakfast cereal and margarine end-product markets. For example, Griffith (2000) found that firms in some parts of the processing and marketing sector exerted market power when purchasing grains and oilseeds from farmers. As noted at the time, this result accorded well with the views of previous regulatory authorities (p.358). In the mid-1990s, the Prices Surveillence Authority (PSA 1994) determined that the markets for products contained in the Breakfast Cereals and Cooking Oils and Fats indexes were "not effectively competitive" (p.14). The PSA consequently maintained price surveillence on the major firms in this product group. The Griffith result is also consistent with the large number of legal judgements against firms in this sector over the past decade for price fixing or other types of non-competitive behaviour. For example, bread manufacturer George Weston was fined twice during 2000 for non-competitive conduct and the ACCC has also recently pursued and won cases against retailer Safeway in grains and oilseeds product lines.

Virtual power producers market strategies

This paper presents MASCEM - a multi-agent based electricity market simulator. MASCEM uses game theory, machine learning techniques, scenario analysis and optimisation techniques to model market agents and to provide them with decision-support. This paper mainly focus on the MASCEM ability to provide the means to model and simulate Virtual Power Producers (VPP). VPPs are represented as a coalition of agents, with specific characteristics and goals. The paper detail some of the most important aspects considered in VPP formation and in the aggregation of new producers and includes a case study.

Multi-agent electricity market simulation with dynamic strategies & virtual power producers

Distributed energy resources will provide a significant amount of the electricity generation and will be a normal profitable business. In the new decentralized grid, customers will be among the many decentralized players and may even help to co-produce the required energy services such as demand-side management and load shedding. So, they will gain the opportunity to be more active market players. The aggregation of DG plants gives place to a new concept: the Virtual Power Producer (VPP). VPPs can reinforce the importance of these generation technologies making them valuable in electricity markets. In this paper we propose the improvement of MASCEM, a multi-agent simulation tool to study negotiations in electricity spot markets based on different market mechanisms and behavior strategies, in order to take account of decentralized players such as VPP.

MASCEM - an electricity market simulator providing coalition support for virtual power players

This paper presents MASCEM - a multi-agent based electricity market simulator. MASCEM uses game theory, machine learning techniques, scenario analysis and optimization techniques to model market agents and to provide them with decision-support. This paper mainly focus on the MASCEM ability to provide the means to model and simulate Virtual Power Players (VPP). VPPs are represented as a coalition of agents, with specific characteristics and goals. The paper details some of the most important aspects considered in VPP formation and in the aggregation of new producers and includes a case study based on real data.

Market power analysis in the Iberian electricity market using a conjectural variations model

In the last years the electricity industry has faced a restructuring process. Among the aims of this process was the increase in competition, especially in the generation activity where firms would have an incentive to become more efficient. However, the competitive behavior of generating firms might jeopardize the expected benefits of the electricity industry liberalization. The present paper proposes a conjectural variations model to study the competitive behavior of generating firms acting in liberalized electricity markets. The model computes a parameter that represents the degree of competition of each generating firm in each trading period. In this regard, the proposed model provides a powerful methodology for regulatory and competition authorities to monitor the competitive behavior of generating firms. As an application of the model, a study of the day-ahead Iberian electricity market (MIBEL) was conducted to analyze the impact of the integration of the Portuguese and Spanish electricity markets on the behavior of generating firms taking into account the hourly results of the months of June and July of 2007. The advantages of the proposed methodology over other methodologies used to address market power, namely Residual Supply index and Lerner index are highlighted. (C) 2014 Elsevier Ltd. All rights reserved.

How market power affects the behaviour of a pumped storage hydro unit in the day-ahead electricity market?

The integration of large amounts of wind energy in power systems raises important operation issues such as the balance between power demand and generation. The pumped storage hydro (PSH) units are seen as one solution for this issue, avoiding the need for wind power curtailments. However, the behavior of a PSH unit might differ considerably when it operates in a liberalized market with some degree of market power. In this regard, a new approach for the optimal daily scheduling of a PSH unit in the day-ahead electricity market was developed and presented in this paper, in which the market power is modeled by a residual inverse demand function with a variable elasticity. The results obtained show that increasing degrees of market power of the PSH unit correspond to decreasing levels of storage and, therefore, the capacity to integrate wind power is considerably reduced under these circumstances.

Exploring the predictive power of Google searches over the US stock market

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics

Demand elasticity and market power in the spanish electricity market

In this paper we check whether generator's bid behavior at the Spanish whosale electricity market is consistent with the hypothesis of profit maximization on their residual demands. Using OMEL data, we find the arc-elacticity of the residual demand around the system marginal price. The results suggest thet the larger firms are not actually profit-msximization. We argue how the regulatory environment may drive these results. Finally, we repeat the analysis for the first session of the intra-day market where presumably firms may not have the same incentives as in the day-ahead market.