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The increasing use of variable generation technologies (VGTs) in power systems, such as wind and photovoltaic generation, has introduced new challenges in the definition of capacity remuneration mechanisms for promoting system reliability. In this context, in this article we propose a novel framework for determining the capacity value of VGTs to contribute to the generation system adequacy, as well as a corresponding method for allocating capacity payments in hydrothermal power systems. We show that the capacity value of VGTs increases with the presence of water reservoirs, since VGTs help relieving hydropower plants from using scarce water resources during off-peak hours thus making more resources available to supply the demand during peak hours.

Summary: The Energy Management System (EMS) is a strong need for achieving cost‐effective, reliable, and pollution‐free operation of microgrids operating in isolated areas. Commonly, the EMS approaches use optimization and rolling‐horizon predictions. However, the inclusion of very short‐term predictions increases the complexity of the optimization, compromising its ability and reliability to operate online. In response to this problem, this paper proposes a rule‐based EMS (RB‐EMS) which uses neither optimization nor prediction horizons. Instead, the RB‐EMS evaluates historical data, and very short‐term predictions to calculate the setpoints of distributed energy resources, and schedulable loads in a cost‐effective, reliable, and sustainable manner. As a form of self‐regulation, the RB‐EMS introduces the Reliability Index to calculate the maximum state of charge of the energy storage system. Given the speed imposed by the very short‐term predictions, the RB‐EMS also introduces a start‐up manager for diesel units that present a dead time in their enlistment. The isolated ESUSCON‐HUATACONDO microgrid was used as a testbed for performance validation. The work shows a first scenario comparing the RB‐EMS against a rolling horizon EMS based on MILP optimization. A second scenario shows the energy management performance with 1 minute predictions. The better results obtained, and the computational simplicity of the RB‐EMS allows propose it to achieve faster and more reliable energy management in other isolated microgrids. [ABSTRACT FROM AUTHOR]

One of the methods for setting distribution tariffs is benchmarking competition. In Chile, a yardstick competition scheme is applied. This yardstick consists of a "model company" that is designed in order to quantify what would be the least cost of operating an efficient distribution company serving the same demand as the actual company. Input data for the design of the company's network are load locations, magnitudes, and growth forecast, and feasible feeder routes. The design of this network, considering its high combinatorial degree, size, and operational constraints, is a difficult task and it is known to be an NP hard problem. In this paper, a new approach is presented where the problem is separated by feeder areas. The criterion used for dividing the areas is to maintain an equitable distribution of loads among them. Two methodologies are compared for area dimensioning: 1) Voronoi tessellation and 2) k-means clustering. Once the feeder areas are defined, the network is designed by applying a genetic algorithm based on the generation of spanning trees. Finally, in order to fulfill real operational constraints, it is considered that all of the feeders share the same output from the substation. This is achieved by using an algorithm that identifies shared routes and performs the final step of the design of the system. [ABSTRACT FROM AUTHOR]

The consideration of uncertainties in the future system operation is a key aspect in current planning methodologies. In this context, load flow studies based on probabilistic theory, fuzzy numbers, and Monte Carlo simulations have been proposed in the literature. This work analyzes in a novel way the application of fuzzy number arithmetic for the DC load flow problem. In this sense, fuzzy sets theory is reviewed and is showed that there are two alternative and valid procedures to perform a subtraction. A key aspect for the right selection of one of these procedures is the independency or dependency among the involved variables. Assuming input data as independent variables, this work is focused on analyzing the fuzzy subtraction between dependent state variables of the system, such as voltage phase angle. Accordingly, two new valid alternative methodologies are proposed and applied to case studies. Results are compared to previous related works showing the consistency of the proposed methodologies. Future research will be focused on the consideration of ohmic losses and AC network modeling in the field of expansion planning studies. [ABSTRACT FROM AUTHOR]

The high penetration of distributed renewable resources requires integration strategies that ensure a balance between supply and demand. Transactive energy (TE) comprises a set of mechanisms capable of achieving this objective by using value as an operational parameter. This paper presents a review of the state of the art in TE, aiming to provide the reader with a general overview of concepts and applications. To accomplish this, the document offers a review of market and operational structures, with a particular focus on the role of TE in the composition of local energy markets. Furthermore, an analysis of the value concept in energy is proposed as a linking element between two current topics of academic interest: multi-energy systems and the water-energy-food nexus. Finally, some international and national pilot projects are showcased, allowing for the identification of the practical validity of the concepts described. [ABSTRACT FROM AUTHOR]