57 research outputs found
Tariff-based regulatory sandboxes for EV smart charging: Impacts on the tariff and the power system in a national framework
Electrification of private transport is a fundamental step for decarbonizing mobility. Electric vehicles (EV) can be a burden for the power system if vehicle-grid integration is not implemented by design. Market-based smart charging projects are effective, but their massive diffusion is limited. A fundamental instrument toward a large adoption of smart charging is the inclusion of smart charging-oriented measures in regulatory sandboxes, conveniently acting on electricity tariff. This paper presents a set of possible toolboxes for smart charging to show the potential that regulatory measures can have on steering the infrastructure deployment and the charging activity. Each proposed toolbox addresses a specific charging mode, including domestic, workplace, and public access charging. Proposed measures are target-oriented and evaluated based on their environmental, technical, and economic impacts. These include the carbon footprint of the electricity used for EV charging, the impact in terms of peak power withdrawal from the public grid and the charging cost born by EV users. Additionally, the assessment about the impact of prospected measures on the electricity tariffs' income is provided. Results show the possibility of reducing the evening EV-related peak load by 30% to 50% via home smart charging. Also, a 10% decrease in carbon footprint is achieved by valley-filling with work charging. Charging at the destination can reduce the system cost for the new distribution infrastructure, dropping the number of new dedicated connection points for public charging. The cost of incentives is partially repayable considering the additional EV penetration fostered by the reduced charging costs
Revenue Stacking for BESS: Fast Frequency Regulation and Balancing Market Participation in Italy
E-mobility scheduling for the provision of ancillary services to the power system
In the present paper, the charging of an electric vehicles fleet is scheduled in order to provide power balance regulation to the electric grid. The starting of e-cars charging can be optimized according to predetermined limits set by users, in order to adjust the power exchange profile of the aggregated fleet. Ancillary services are sold on the Ancillary Services Market. Therefore, an analysis of the Italian Ancillary Services Market is provided to check the performance of the strategy proposed according to the actual market requirements. In this way, useful figures are provided to the reader in order to evaluate the technical and economic viability of the approach
Opportunities for DERs in Ancillary Services Markets: analysis and deployment strategies in a national framework
BESS modeling: Investigating the role of auxiliary system consumption in efficiency derating
Large-scale Battery Energy Storage System (BESS) capacity installed for stationary applications is rising in the first decades of 21st century. Business models related to BESS highly depend on BESS lifetime. BESS lifetime can be preserved only if accurate thermal management of the assets allows to keep it at design temperature. Auxiliary systems' needs for cooling and heating the BESS cannot be disregarded while modeling the real-world operation of these facilities. In this paper we propose an improved protocol for organic modeling of large-scale BESS grid-connected. We assess the share of losses and the operational efficiency related to the provision of ancillary services to the network by BESS in different seasons and different working conditions. We highlight that BESS efficiency increases in case the system is constantly exploited, avoiding time idle or at low power. The model proposed, with respect to standard techniques, allows to better represent BESS performance. Indeed, just by disregarding the losses related to thermal management of the assets (as it is for standard modeling techniques), errors committed are up to 10%
Ancillary services markets in europe: Evolution and regulatory trade-offs
The generating power mix has deeply changed in the last years. Especially in Europe, the electric systems are evolving towards a more decentralized architecture, widely penetrated by renewable and distributed energy resources. These resources usually present less predictability and fast dynamics. To avoid jeopardizing the power system, they should be effectively included in the Ancillary Services Markets (ASMs), which procure the resources for balancing and safely dispatching the system. This work presents a meta-analysis of the evolution of ASMs and the underlying regulatory trade-offs. The evolutions are analyzed modularly to clearly investigate the benefit of each one. The analysis aims to provide an evaluation of each trend regarding the architecture, the services, and the products of the ASMs, based on the level of agreement of the two main counterparties: the system operator who manages the system and the Balancing Services Provider that delivers the service. The outcome is a ranking of the possible regulatory evolutions, with the win–win situations at the top and the cases that imply drawbacks for a counterparty at the bottom. The ranking can represent a guideline for regulatory authorities as well as market operators or players to realize effective market arrangements. Finally, a survey of European countries describes the effort of each one towards each evolution
Service stacking on residential BESS: RES integration by flexibility provision on ancillary services markets
Opening of the Italian Ancillary Service Market to Distributed Energy Resources: Preliminary Results of UVAM project
The present paper deeply analyzes the main features and the preliminary results of the UVAM project: a pilot project launched in 2017 by the Italian Regulatory Authority that aims to investigate the technical and economic feasibility of the provision of ancillary services by Distributed Energy Resources (DERs), controllable loads, energy storage systems and e-mobility. Indeed, the rising of renewables and DERs penetration in the power system recently called for the enlargement of the pool of actors that can actively participate in the grid balancing. The UVAM project represents the first opening of the Italian Ancillary Service Market to distributed resources and, for the first time, a capacity remuneration is also added to remunerate the provision of ancillary services. The results for the period November 2018 - March 2020 are analyzed both from technical and economic perspective, highlighting the main difficulties faced in the experimentation, while trying to interpret the behavior adopted by Aggregators in this first phase of the project
Grid-scale BESS for ancillary services provision: SoC restoration strategies
The future power system, characterized by lower inertia, reduced programmability and more distributed architecture, will depend on prompt and reliable control systems. Quick ancillary services provided by battery energy storage systems (BESS) could be a resource in order to deliver fast and precise response to frequency events. Degrees of freedom in the design of innovative products traded on ancillary services markets give the asset manager room for developing state-of-charge (SoC) restoration mechanisms. These are necessary to effectively exploit BESS as key resources for electricity balancing. This study compares the main SoC restoration strategies. It aims to define which ones are suitable for guaranteeing the reliability of the provision and the return on the investment. A robust regulatory framework analysis describes the degrees of freedom guaranteed by the main experiences around Europe. In this paper, a BESS model with variable efficiency is used to compare the provision of Frequency Containment Reserve (FCR) with different SoC restoration strategies exploiting one or more degrees of freedom. Here, we show that the degrees of freedom are key to the reliability of provision. Among most diffused mechanisms, dead-band strategies secure the desired consistency, but require large energy flows for SoC management. Thus, BESS life and economics decrease. The strategies based on minimum available energy guarantee assured reliability while being fair with BESS life and operation costs
Pregnancy outcome among HIV positive and negative intravenous drug users
Objective: To analyze determinants of pregnancy outcome, among HIV infected and uninfected intravenous drug users. Study design: A total of 315 pregnant current intravenous drug users, IVDU (151 HIV infected and 164 HIV uninfected subjects) were referred to the Center for Pregnant Drug Addicts of the Mangiagalli Clinic, Milan, Italy, for internatal care and delivery between 1985 and 1993. Results: HIV uninfected and infected mothers did not differ significantly according to type of pregnancy, gestational age at childbirth, mode of delivery, pregnancy outcome and newborn weight, height, head circumference, sex and Apgar at 1 and 5 min. Out of 133 children (born to HIV infected mothers) for whom HIV status was available, 20 (15%) were HIV infected or developed AIDS-related signs and symptoms during a 24 months follow-up. The distribution of HIV infected and non infected infants was not significantly different as regards maternal CD4 lymphocyte count, week of gestation at birth, mode of delivery, infant weight, height, head circumference and Apgar at 1 and 5 min. Conclusion: Our data show that HIV infected women in the early stages of HIV infection are not at a higher risk of adverse course of pregnancy than HIV uninfected women. Vertical transmission rates were not associated to newborn characteristics
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