1,721,012 research outputs found
Smart grids, energy production and private investments: a real option approach
Full text linkIn Italy – and in the countries working for GHG emissions reduction - the last decade was characterized by a large development of distributed generation power plant. Private investment in the sector have been heavily boosted with monetary incentives, like guaranteed feed-in tariffs, especially for the photovoltaic sector. These incentives, on one hand, allowed for developing photovoltaic technology faster, guaranteeing payoffs for huge initial investments, but on the other hand they cause an increase in public costs, regarding both monetary disbursement to pay incentives and system costs connected to the management of a number of energy sources not efficiently integrated. To allow the development of photovoltaic energy production in a sustainable way, it’s necessary to find how to design economic payoff for private investors and to ask them to collaborate for system balancing and management: this objective shall be reached implementing a Smart Grid.
Methods
In our work, we consider a private energy consumer that have the possibility to invest in a photovoltaic power plant, from which it’s possible to directly consume electricity for private use, or to sell it to the market: in this way, the consumer becomes a potential prosumer, whose plant dimension (power) will be a result of the investment evaluation. To evaluate the investment decision, the consumer shall compare if the new condition allows for savings on energy expenditure: in order to do this, we perform a real option analysis of the private cost function, considering as possibilities for the prosumer 1) buy all the energy from the main grid and sell energy privately produced outside; 2) consume all the energy produced with the photovoltaic plant and buy outside only what exceeds the private production; 3) a mix of the two. Decision depends on prices: external energy price is fixed with a contract; selling price to the grid is uncertain and it depends on instantaneous technical grid necessities – Smart Grid tools allow for instantaneous information exchange on grid status and immediate agent reaction to the signals.
Results
The analysis shows that external energy price (national grid price) is not affecting decisions on plant dimension, but is relevant while deciding when to invest. Selling price, indeed, influences investment decisions on plant size: if the investor is given the possibility to sell energy to the grid, it could be convenient to choose a higher level of plant power. Since the selling price is the expression of grid technical needs (such as balancing), we can deduce that investments will take place preferably where 1) the possibility for the prosumer to participate to grid management through decisions on production and consumption is present – with Smart Grid tools and 2) where technical characteristics of the grid ask for more support from the local agents (higher energy selling prices).
Conclusions
The development of distributed power plant, in the future, shall be managed through a system that allow for a better integration of renewable energy plants, calling for private actions helping grid management.
The Smart Grid environment allows for an instantaneous interaction between the agent and the grid: depending on its needs, the grid can send signals (through prices) to the agents, and the agents have the possibility to respond to the signals having a monetary gain. In this way, the system can allow for better integration of the renewable – that collaborate in keeping the grid stable – and for a photovoltaic development without costly monetary incentives. What is relevant, indeed, is that this value is created by a Smart Grid, on which we shall invest
The varieties of bifocal Grassmann tensors
Full text linkGrassmann tensors arise from classical problems of scene reconstruction in computer vision. In particular, bifocal Grassmann tensors, related to a pair of projections from a projective space onto view spaces of varying dimensions, generalize the classical notion of fundamental matrices. In this paper, we study in full generality the variety of bifocal Grassmann tensors focusing on its birational geometry. To carry out this analysis, every object of multi-view geometry is described both from an algebraic and geometric point of view, e.g., the duality between the view spaces, and the space of rays is explicitly described via polarity. Next, we deal with the moduli of bifocal Grassmann tensors, thus showing that this variety is both birational to a suitable homogeneous space and endowed with a dominant rational map to a Grassmannian
Business Models for Energy Community in the Aggregator Perspective: State of the Art and Research Gaps
Full text linkDistributed Energy Resources (DERs) are spreading under the pressure of climate change mitigation plans and the framework, recognized as the most suitable to exploit DER diffusion, is the Energy Community (EC). Understanding the role of energy companies, especially Aggregators, in this context, is still an open topic, as it is not clear how they can support members in the aggregation process and how they create value through their business. The aim of the study is therefore to revise whatever is currently present in the research agenda and consequently a systematic literature review has been carried out. The contribution of this work consists of illustrating the main features of Aggregators, pointing out how they implement their strategies in the energy markets, with which services they capture value, who their partners and customers are, what the financial aspects are of their activities with respect to the size of the aggregated clusters, and, in conclusion, which are the main business model structures currently deployed. Then, considerations are made concerning EC context, identifying the areas where an Aggregator could usefully support communities’ establishment and management, solving well-known hindrances, and what gaps future research should fill
The participation of small-scale variable distributed renewable energy sources to the balancing services market
Full text linkThe paper considers different market settings for the participation to the balancing services market of small scale variable renewable energy sources connected to the distribution grid. By mixing an economical and a technical approach, it evaluates the efficiency of participation to the market under two distinct approaches to resources' aggregation: a commercial scheme and a technical one. In the former, the supply of the small scale variable distributed renewable energy sources is grouped on a purely commercial basis; in the latter, the distribution system operator is responsible of the imbalances that may possibly arise in the distribution grid and aggregates the sources from a technical perspective. By considering a reference distribution network and designing scenarios for the forecast uncertainty about supply and demand of power profiles, the impact of different market frameworks is assessed. The upward and downward balancing services provided by variable distributed energy resources and controllable units connected to the high voltage grid are both considered. Moreover, the power supply curtailments, that endogenously arise due to the violation of technical constraints of the distribution grid and the random nature of energy supply by renewables, are addressed, for each specific market model. As a general outcome of this research, it is shown that providing balancing energy based on a commercial approach is preferable as long as renewables' curtailment penalty is low and local generators have correlated forecast errors (as in the case of photovoltaic units) with a large reserve capacity. High penalties for curtailment and lower correlation among generation schedule deviations, along with a lower reserve by distributed units, make the technical approach more convenient
Electricity prices in Italy: Data registered during photovoltaic activity interval
No full textData we present in this article are related to the research article by Bertolini M., D'Alpaos C. and Moretto M. “Do Smart Grids boost investments in domestic PV plants? Evidence from the Italian electricity market”(Bertolini et al., 2018) [1]. The dataset is an elaboration of historical spot prices provided by the Italian Gestore dei Mercati Energetici (GME) and gives information about average prices registered during the day, when photovoltaic (PV) plants are – on average – expected to produce energy. Prices are stated in €/MW
Competition in smart distribution grids
No full textSmart grids are often considered a cornerstone of energy transition and market liberalization in electric industries. From a critical reading of the interdisciplinary academic and governmental literature, we draw a new definition of grid smartness that is based on the reduction of the volatility of market prices and flows. Then, relying on a simple industrial-organization model of the electric market, we analyze the impact of smart grids on competition among energy suppliers and on the incentives of distribution system operators to invest in it. We show that the risk-reduction effect of smart grids pushes firms to supply more energy. However, the latter can be compensated by an indirect competition effect of investments in smart grids which prevents the entry of firms into the market, though the aggregate effect on energy supply is always positive. We also find that distribution system operators under-invest in smart grids because they fail to internalize positive externalities on energy consumers and producers
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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