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Publicações

Publicações por José Villar

2020

Circular economy in plastic waste - Efficiency analysis of European countries

Autores
Robaina, M; Murillo, K; Rocha, E; Villar, J;

Publicação
SCIENCE OF THE TOTAL ENVIRONMENT

Abstract
The way plastics are currently produced, used and disposed does not capture the economic benefits of amore 'circular' approach and is dramatically harming the environment. It is relevant to determine which European countries can be considered more or less efficient in the end-of-life of plastic products processes, what the sources of the inefficiencies are, and howthose less efficient countries could improve their performance towards a more circular economy. Although some countries have developed a variety of quantitative indicators, there is scarcity of adequate metrics for performance measurements. This paper estimates the efficiency of 26 European countries in the context of Circular Economy, for the period 2006-2016, considering the generation of waste, recovery and recycling of plastic, with a methodology based on theMultidirectional Efficiency Analysis. Apart from identifying the most efficient countries in the studied period, results show that efficiency increases for most countries with time, and that many countries reach the full efficiency by the end of the study period, and especially by 2016. Input analysis shows that increasing capital seems to be a main driver towards efficiency, since the other inputs are used with a similar efficiency by most countries. Output analysis suggest that the difference among countries efficiency is not in their reduction of total waste or emissions, but rather in the improvement of their economic growth in a circular way, that is, improving GDP but also the recovering and recycling activities. These results could be useful to design policies towards a more efficient and circular use of plastics.

2020

Local Market for TSO and DSO Reactive Power Provision Using DSO Grid Resources

Autores
Retorta, F; Aguiar, J; Rezende, I; Villar, J; Silva, B;

Publicação
ENERGIES

Abstract
This paper proposes a near to real-time local market to provide reactive power to the transmission system operator (TSO), using the resources connected to a distribution grid managed by a distribution system operator (DSO). The TSO publishes a requested reactive power profile at the TSO-DSO interface for each time-interval of the next delivery period, so that market agents (managing resources of the distribution grid) can prepare and send their bids accordingly. DSO resources are the first to be mobilized, and the remaining residual reactive power is supplied by the reactive power flexibility offered in the local reactive market. Complex bids (with non-curtailability conditions) are supported to provide flexible ways of bidding fewer flexible assets (such as capacitor banks). An alternating current (AC) optimal power flow (OPF) is used to clear the bids by maximizing the social welfare to supply the TSO required reactive power profile, subject to the DSO grid constraints. A rolling window mechanism allows a continuous dispatching of reactive power, and the possibility of adapting assigned schedules to real time constraints. A simplified TSO-DSO cost assignment of the flexible reactive power used is proposed to share for settlement purposes.

2020

Joint analysis of the Portuguese and Spanish NECP for 2021-2030

Autores
De Oliveira, AR; Collado, JV; Lopes, JAP; Saraiva, JPT; Fonseca, NS; Domenech, S; Campos, FA;

Publicação
International Conference on the European Energy Market, EEM

Abstract
The European Union (EU) energy strategy towards decarbonization led EU countries to elaborate their corresponding National Energy and Climate Plans (NECP) for the period 2021 to 2030. This paper analyzes the Portuguese and Spanish NECPs concerning their power systems. CEVESA, a model for the long-term planning and operation of the Iberian electricity system, is used. The analysis is based on simulating the reference NECP scenario, as well as other alternative scenarios with different solar and wind generation shares, CO2 prices and fuel costs. Results provide insights on the MIBEL electricity market evolution under the current decarbonization national strategies. © 2020 IEEE.

2020

Costs Impact of a Transition to Hydrogen-fueled Vehicles on the Spanish Power Sector

Autores
Villar, J; Olavarria, B; Domenech, S; Campos, FA;

Publicação
UTILITIES POLICY

Abstract
It is expected that demand response might provide soon ancillary services to the power system. This could be done, for example, by managing the use of Electric Vehicles (EV) batteries, or the production of flexible energy commodities such as hydrogen (H-2), that can be used for fuel cell vehicles (H2EV) or in industrial processes. This paper analyses the impact of a transition to H2EV as an alternative to EV for passengers' cars on a Spanish-like power sector. A simple H-2 demand estimation is developed and provided to CEVESA, an operation and expansion model for the Iberian Power System Electricity Market (MIBEL). For this study, CEVESA was extended to include the investments and operation decisions of H-2 production. Simulations were performed to determine the optimal evolution of the H-2 production capacity and of the electricity generation mix, considering scenarios with different shares of EV and H2EV. The impact of H2EV vs EV mobility is assessed based on the recent Spanish National Plan for Energy and Climate (NECP) as the base case scenario. Results show that, even if H2EV mobility alternative is still more costly than EV, H-2 production could provide a significant flexibility to the system that should also be appraised. Indeed, H2EV mobility could become a feasible and complementary alternative to decarbonize mobility by powering H-2 production with the renewable generation surplus. This, together with the on-going learning process of this technology that will decrease its production costs and increase its efficiency in the coming years, could boost, even more, the development of the H-2 economy.

2020

The Food Bank of Madrid: A Linear Model for Optimal Nutrition

Autores
Castanon, R; Campos, FA; Martinez, SD; Villar, J;

Publicação
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH

Abstract
This work proposes a mathematical linear programming model that addresses the food provisioning problem of the food bank of Madrid. It aims to determine the most appropriate weekly decisions to meet the macro-nutritional requirements of the beneficiaries of this social service, by minimizing the total cost considering third-party donations. The model has been applied to a realistic case study considering a sociological structure of beneficiaries categorized by age and gender and representing the first decile of incomes of the Spanish population. The demand of macronutrients is satisfied by means of nine different groups of food, used to provide some level of variability in the consumption patterns of the beneficiaries. The results provide insight on cost-cutting opportunities related to centralizing the decision-making process, indicating a 10% reduction both in provisioning costs and food quantities. This suggests that the proposed model might serve as a tool for designing new strategies for the provisioning or evaluation of economic and social support policies for the food bank of Madrid.

2020

Local Energy Markets for Energy Communities with Grid Constraints

Autores
Rocha R.; Collado J.V.; Soares T.; Retorta F.;

Publicação
International Conference on the European Energy Market, EEM

Abstract
Renewable energy communities (REC) and local energy markets (LEM) emerge as entities capable, not only to promote the penetration of renewable energy sources into lower levels of the grid, but also to manage distributed energy resources (DER) and local energy exchanges between small players. This paper proposes a benefit assessment among different regulatory frameworks for LEM, considering network constraints and a virtual storage unit. Results show significant savings can be achieved, even without storage. Therefore, the continuous increase of DER can have considerable grid impacts if not complemented by other structures as storage or by alternative market services like flexibility.

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