293 research outputs found
The impact of RES-E policy setting on integration effects - A detailed analysis of capacity expansion and dispatch results
The operation of the power markets is strongly aected by the presence of high shares of electricity from renewable energy sources (RES-E) in the market. Especially in times of high RES-E infeed, rm market situations can lead to extreme results, even to negative power prices. The behavior of RES-E in potential oversupply situations depends on the RES-E support scheme and in particular on the dened curtailment rules. By now, dierent curtailment rules have not been taken into account in long-run capacity expansion analyses. The present research investigates the impact of curtailment rules on the operation and the investment decisions through the utilization of "The High Temporal Resolution Electricity Market Analysis Model" (THEA) for the German power market under consideration of the neighboring countries. In general the results show that RES-E can provide exibility to the system if low burdens for curtailment are applied. This comes with the cost of lacking market signals which could trigger investments in exible generation capacities. However, if RES-E are forced into the market at any cost, the burden for consumers increases and the market signals high demand for alternative exibilities.Power market modeling, RES-E integration, curtailment rules
Hedging error in Lévy models with a Fast Fourier Transform approach
We measure, in terms of expectation and variance, the cost of hedging a contingent claim when the hedging portfolio is re-balanced at a discrete set of dates. The basic point of the methodology is to have an integral representation of the payoff of the claim, in other words to be able to write the payoff as an inverse Laplace transform. The models under consideration belong to the class of Lévy models, like NIG, VG and Merton models. The methodology is implemented through the popular FFT algorithm, used by many financial institutions for pricing and calibration purposes. As applications, we analyze the effect of increasing the number of tradings and we make some robustness tests.Hedging, Lévy models, Fast Fourier Transform
The Economics of Renewable Electricity Market Integration. An Empirical and Model-Based Analysis of Regulatory Frameworks and their Impacts on the Power Market
As power systems increase in complexity due to higher shares of intermitting RES-E, so increase the requirements for power system modeling.
This thesis shows empirically, with examples from Germany and Texas, that the increasing RES-E share strongly affects current power market operation. The markets further create price signals, which lead to system adaptations in the long-run.
To get an estimate of the adaptation effects, 'The High Temporal Resolution Electricity Market Analysis Model' (THEA) has been developed. In a first application for the ERCOT market in Texas, particular model attributes are tested and compared to some complexity reducing approaches, i.e. the reduction of temporal resolution and the reduction of operational constraints. In both cases, the results show significant differences compared to the results when the full spectrum of THEA's capabilities is utilized. The ERCOT case study additionally shows that the adaptation to RES-E in an isolated, mainly thermal-based power system is quite severe. Market signals which underline this conclusion are the severely reduced value of wind energy, the increasing curtailment and the strong shift towards peak-oriented generating capacities.
The second application of THEA models the German power market with its interconnected markets. This analysis increases the complexity significantly by modeling a well interconnected system, increasing the amount of different RES-E technologies and adding CAES investment options. In order to assess the impact on the different system component's supply, demand and grid infrastructure, specific measures are applied to compare several scenarios. Each scenario represents a policy option, which either reduces or increases the flexibility of the power system. The scenario comparisons capture the effects of a lower RES-E share, a larger baseload capacity fleet, higher interconnector capacities, various RES-E support scheme designs and the capability of RES-E to participate in the reserve power market.
In general, the results show that if the flexibility of one system component is reduced, the flexibility values of other system components increase, which suggests a careful, integrated and long-term oriented policy setting
The cost of sustainability on optimal portfolio choices
We examine the impact of sustainability criteria, as measured by the KLD scores, on optimal portfolio selection performed on an investment universe containing the equities in the S&P500 index and covering the period between 1993 and 2008. The optimizations are done according to the Markowitz mean-variance approach while sustainability constraints are introduced by eliminating from the investment pool those assets that do not comply to di®erent social responsibility criteria (screening). We compare the two efficient frontiers, i.e. the one without and the one with screening. A spanning test is performed to determine if the differences between the two types of efficient frontier are significant. We introduce a measure of how much an investor has to pay (through loss of return or through additional risk) in order to satisfy given sustainability criteria. The analysis is carried on separately on the three main dimensions of sustainability, namely Environmental, Social and Governance.Sustainability; Optimal portfolio
The cost of sustainability on optimal portfolio choices
We examine the impact of including sustainability related constraints on optimal portfolio selection. Our analysis covers an investment set containing the components of the S&P500 index from 1993 to 2008. The optimizations are performed according to the classical mean-variance approach while sustainability constraints are introduced by eliminating from the investment pool those assets that do not comply to given social responsibility criteria (screening). We compare the efficient frontiers with and without screening. The analysis is performed on the three main dimensions of sustainability, namely Environmental, Social and Governance. We find that socially responsible screening implies a small loss in terms of Sharpe Ratio even though it has a strong impact on the market capitalization of the optimal port-folio. The spanning test shows that the ex-post differences between the two frontiers, when short selling is not allowed, are significant only in the case of Environmental screeningSocially responsible investments, optimal portfolios, screening.
How to measure Corporate Social Responsibility
Compliance with Corporate Social Responsibility (CSR) standards may require capacity that varies from one aspect to the other and companies in different industries may encounter different difficulties. Since CSR is a multidimensional concept, latent variable models may be usefully employed to provide a unidimensional measure of the ability of a firm to fulfil CSR standards. A methodology based on Item Response Theory has been implemented on the KLD sustainability dataset. Results show that companies in the industries Oil & Gas, Industrials, Basic Materials and Telecommunications have a higher difficulty to meet the CSR standards. Criteria based on Environment, Community relations and Product quality have a large capacity to select the firms with the best CSR performance, while Governance does not exhibit similar behavior. A stock selection based on the ranking of the firms according to our CSR measure outperforms, in terms of risk-adjusted returns, stock selection based on other criteria.Socially Responsible Investment, CSR ability, latent variable model, item response theory
HUMAN CAPITAL AND FAMILY FARM IN THE OLIVE GROWING SYSTEM OF THE CALABRIA REGION
This research aims at pointing out those constrains and incentives conditioning family farm choices about investments, technical and managerial knowledge and expertness. The planned target has to be achieved through the attainment of three stages. Family farm involves a lot of people by different kind of employee relations, based mostly on a temporary work, that are often within the limits of the work rules. The organization solutions adopted by family farm produce several effects: among which investments and human capital allotment stand out. This research analyses family farm characteristics in a local rural system of the Calabria Region, as the result of the various European Community and domestic interventions and the specific physical, social and economic features in the considered territory; the attention is focused on the olive growing family farm. The survey is made through interviews carried out by qualified operators using questionnaires organized on different modules.Human capital, Family farm, Agricultural labour, Agribusiness, Labor and Human Capital,
Stability, Flying Qualities and Parameter Estimation of a Twin-Engine CS23/FAR23 Certified Light Aircraft
This paper presents some results of the flight test campaign conducted on the Tecnam P2006T aircraft, on the occasion of its certification process. This twin-engine propeller airplane is certified in the category CS23/FAR23. Many preliminary flight tests on a prototype of this light aircraft were aimed at optimizing performances and flight qualities. These experiences led to the application of two winglets to the original wing. The final configuration was extensively tested for the purpose of CS23 certification achievement. At the same time the airplane model, through a dedicated set of flight maneuvers, has been characterized by means of parameter estimation studies. The longitudinal and lateral-directional response mode were assessed and quantified. All the aircraft stability derivatives have been estimated from the acquired flight data using the well-known Maximum Likelihood Method (MLM). Some estimated stability derivatives have been also compared with the corresponding values extracted from leveled flight tests and from wind-tunnel tests performed on a scaled model of the aircraft
Notes on the Sardinian endemic Tenuiphantes sardous (Gozo, 1908) n. comb. (Araneae: Linyphiidae)
Isaia, Marco, Nicolosi, Giuseppe (2023): Notes on the Sardinian endemic Tenuiphantes sardous (Gozo, 1908) n. comb. (Araneae: Linyphiidae). Fragmenta entomologica 55 (1): 31-36, DOI: 10.13133/2284-4880/1509, URL: http://dx.doi.org/10.1200/PO.23.0010
Distribution and bioclimatic suitability of Duvalius hartigi,subterranean beetle from the lava caves of Mount Etna (Coleoptera: Carabidae, Trechinae)
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