Optimal Net-Load Balancing in Smart Grids with High PV Penetration

Mitigating Supply-Demand mismatch is critical for smooth power grid operation. Traditionally, load curtailment techniques such as Demand Response (DR) have been used for this purpose. However, these cannot be the only component of a net-load balancing framework for Smart Grids with high PV penetration. These grids can sometimes exhibit supply surplus causing over-voltages. Supply curtailment techniques such as Volt-Var Optimizations are complex and computationally expensive. This increases the complexity of net-load balancing systems used by the grid operator and limits their scalability. Recently new technologies have been developed that enable the rapid and selective connection of PV modules of an installation to the grid. Taking advantage of these advancements, we develop a unified optimal net-load balancing framework which performs both load and solar curtailment. We show that when the available curtailment values are discrete, this problem is NP-hard and develop bounded approximation algorithms for minimizing the curtailment cost. Our algorithms produce fast solutions, given the tight timing constraints required for grid operation. We also incorporate the notion of fairness to ensure that curtailment is evenly distributed among all the nodes. Finally, we develop an online algorithm which performs net-load balancing using only data available for the current interval. Using both theoretical analysis and practical evaluations, we show that our net-load balancing algorithms provide solutions which are close to optimal in a small amount of time.Comment: 11 pages. To be published in the 4th ACM International Conference on Systems for Energy-Efficient Built Environments (BuildSys 17) Changes from previous version: Fixed a bug in Algorithm 1 which was causing some min cost solutions to be misse

Optimal Customer Targeting for Sustainable Demand Response in Smart Grids1

AbstractDemand Response (DR) is a widely used technique to minimize the peak to average consumption ratio during high demand periods. We consider the DR problem of achieving a given curtailment target for a set of consumers equipped with a set of discrete curtailment strategies over a given duration. An effective DR scheduling algorithm should minimize the curtailment error - the difference between the targeted and achieved curtailment values - to minimize costs to the utility provider and maintain system reliability. The availability of smart meters with fine-grained customer control capability can be leveraged to offer customers a dynamic range of curtailment strategies that are feasible for small durations within the overall DR event. Both the availability and achievable curtailment values of these strategies can vary dynamically through the DR event and thus the problem of achieving a target curtailment over the entire DR interval can be modeled as a dynamic strategy selection problem over multiple discrete sub-intervals. We argue that DR curtailment error minimizing algorithms should not be oblivious to customer curtailment behavior during sub-intervals as (expensive) demand peaks can be concentrated in a few sub-intervals while consumption is heavily curtailed during others in order to achieve the given target, which makes such solutions expensive for the utility. Thus in this paper, we formally develop the notion of Sustainable DR (SDR) as a solution that attempts to distribute the curtailment evenly across sub-intervals in the DR event. We formulate the SDR problem as an Integer Linear Program and provide a very fast -factor approximation algorithm. We then propose a Polynomial Time Approximation Scheme (PTAS) for approximating the SDR curtailment error to within an arbitrarily small factor of the optimal. We then develop a novel ILP formulation that solves the SDR problem while explicitly accounting for customer strategy switching overhead as a constraint. We perform experiments using real data acquired from the University of Southern Californias smart grid and show that our sustainable DR model achieves results with a very low absolute error of 0.001-0.05 kWh range

Integración de los recursos energéticos distribuidos en microrredes aisladas: paradigma colombiano

The electrification of rural or isolated areas coupled with increasing environmental concerns have promoted the emergence of Distributed Energy Resources (DER) and the operation by isolated microgrids. However, the integration of such resources involves technical issues related to the reliability and continuity of the electricity supply. Indeed, the uncertainty of renewable generation sources and the reduced inertia of isolated microgrids are challenges for the operation of these distribution systems. One way to address them is by providing ancillary services through all the resources involved in the system’s operation (generation assets, demand share, and storage systems). Accordingly, this paper first presents a literature review of the challenges and potential benefits of integrating DERs into the operation of a distribution system. It also includes some common strategies to mitigate the vulnerability of the introduction of these technologies in microgrids. Afterwards, the current state of each type of resource in Colombia is assessed. Finally, some basic strategies that enhance the benefits of DER integration are outlined along with the overcoming of challenges of microgrid operation in said country. To that end, we consider isolated Colombian regions to be natural laboratories where the effects of DER integration and the requirements for the operation by local production units can be analyzed.La electrificación de áreas rurales o aisladas, junto con las crecientes preocupaciones ambientales, han promovido la aparición de Recursos Energéticos Distribuidos (DER), y la operación por microrredes aisladas. Sin embargo, la integración de dichos recursos trae consigo problemas técnicos relacionados con la confiabilidad y la continuidad del suministro de electricidad. De hecho, la variabilidad e incertidumbre del recurso primario de las fuentes de generación renovables y la poca inercia de las microrredes aisladas son desafíos que se enfrentan en la operación de estos sistemas de distribución. Una forma de responder a estos desafíos es brindando servicios complementarios a través de todos los recursos inmersos en el funcionamiento del sistema (activos de generación, participación de la demanda y sistemas de almacenamiento). Este artículo muestra una revisión de los desafíos y beneficios potenciales de la Integración de DER, en la operación del sistema de distribución reportados en la literatura, junto con algunas estrategias comunes para mitigar la vulnerabilidad de la introducción de estas tecnologías en microrredes. Asimismo, realiza una evaluación del estado actual de cada recurso en Colombia; finalmente, se describen algunas estrategias para aumentar del impacto de los beneficios de la Integración de DER y la superación de algunos desafíos planteados en la operación por microredes en Colombia. Para ello, se considera a las regiones aisladas de Colombia como un laboratorio natural, donde sería posible analizar los efectos de la Integración de DER, así como los requisitos para la operación por parte de las unidades de producción locales

Integration of distributed energy resources in isolated microgrids: the Colombian paradigm

La electrificación de áreas rurales o aisladas, junto con las crecientes preocupaciones ambientales, han promovido la aparición de Recursos Energéticos Distribuidos (DER), y la operación por microrredes aisladas. Sin embargo, la integración de dichos recursos trae consigo problemas técnicos relacionados con la confiabilidad y la continuidad del suministro de electricidad. De hecho, la variabilidad e incertidumbre del recurso primario de las fuentes de generación renovables y la poca inercia de las microrredes aisladas son desafíos que se enfrentan en la operación de estos sistemas de distribución. Una forma de responder a estos desafíos es brindando servicios complementarios a través de todos los recursos inmersos en el funcionamiento del sistema (activos de generación, participación de la demanda y sistemas de almacenamiento). Este artículo muestra una revisión de los desafíos y beneficios potenciales de la Integración de DER, en la operación del sistema de distribución reportados en la literatura, junto con algunas estrategias comunes para mitigar la vulnerabilidad de la introducción de estas tecnologías en microrredes. Asimismo, realiza una evaluación del estado actual de cada recurso en Colombia; finalmente, se describen algunas estrategias para aumentar del impacto de los beneficios de la Integración de DER y la superación de algunos desafíos planteados en la operación por microredes en Colombia. Para ello, se considera a las regiones aisladas de Colombia como un laboratorio natural, donde sería posible analizar los efectos de la Integración de DER, así como los requisitos para la operación por parte de las unidades de producción locales.The electrification of rural or isolated areas coupled with increasing environmental concerns have promoted the emergence of Distributed Energy Resources (DER) and the operation by isolated microgrids. However, the integration of such resources involves technical issues related to the reliability and continuity of the electricity supply. Indeed, the uncertainty of renewable generation sources and the reduced inertia of isolated microgrids are challenges for the operation of these distribution systems. One way to address them is by providing ancillary services through all the resources involved in the system’s operation (generation assets, demand share, and storage systems). Accordingly, this paper first presents a literature review of the challenges and potential benefits of integrating DERs into the operation of a distribution system. It also includes some common strategies to mitigate the vulnerability of the introduction of these technologies in microgrids. Afterwards, the current state of each type of resource in Colombia is assessed. Finally, some basic strategies that enhance the benefits of DER integration are outlined along with the overcoming of challenges of microgrid operation in said country. To that end, we consider isolated Colombian regions to be natural laboratories where the effects of DER integration and the requirements for the operation by local production units can be analyzed

Methodological Proposal: First Steps for the Implementation of Demand Management Programs in Colombia

The electrification of isolated or rural areas brings with it technical, economic, and social challenges that differentiate the operation of these networks compared to the traditional operation of large electrical power systems, such as the dependence of air or river transport on fuel for the supply of generation plants, the absence of individual measurement and the obsolete infrastructure of the distribution networks. Therefore, this paper proposes a hybrid methodology for studying a Colombian case, analyzing the development of programs for rational electricity use and energy efficiency in isolated areas. These first steps are related to the diagnosis of the current conditions of the power network, the identification of actors that can influence the regulation of the electricity service in the area, and the proposal of mechanisms that allow promoting the rational and efficient use of the electricity

Caracterización de un esquema remunerativo para la participación de la demanda en la prestación del servicio complementario de control de frecuencia en el mercado eléctrico colombiano

La modernización de los sistemas eléctricos existentes, junto con las crecientes preocupaciones ambientales, han promovido la integración de fuentes de energía renovable a los sistemas eléctricos de potencia y el surgimiento de programas de respuesta de la demanda. Sin embargo, la introducción de estas fuentes de generación variable lleva a que cada vez se presentarán más y mayores variaciones en la frecuencia del sistema debidas a la intermitencia de los recursos renovables, lo que hace necesario el surgimiento de nuevos mecanismos que permitan la prestación adecuada del servicio complementario de control de frecuencia en ambientes de alta penetración de generación variable. En esta perspectiva, esta tesis propone la integración de la respuesta de la demanda en el servicio complementario de control de frecuencia en sistemas con alta penetración de generación variable, mediante la caracterización de un esquema remunerativo que se adapte a las condiciones del mercado eléctrico colombiano. Para ello se realiza una revisión bibliográfica de las principales investigaciones que consideran a la demanda como un recurso adicional a la generación con el potencial de participar en la prestación del servicio complementario de control de frecuencia, y se establece un modelo de relaciones causales que permite dividir la participación de la demanda en la regulación de frecuencia en tres grandes categorías. A la par que se propone un modelo para el diseño y evaluación de un esquema de tarifas por tiempo de uso, para la vinculación de grandes bloques de la población en la prestación del servicio complementario de control de frecuencia, por medio de la acotación del rango en el que varía la frecuencia diariamenteAbstract Modernization of existing power systems, coupled with increasing environmental concerns, have promoted the emergence of renewable energy sources and demand response programs. However, the integration of generation units from variable energy sources leads to have more variations in the frequency of the system, due to the intermittency of renewable resources. This makes it necessary to have new mechanisms to allow the adequate provision of ancillary services when there are high penetration levels of variable generation. In this perspective, this study proposes the integration of demand response in the frequency control ancillary service in systems with high penetration of variable generation, through the characterization of remunerative schemes which can be adapted to the conditions of the Colombian electricity market. With this aim, a bibliographic review of the main researches that consider the demand as a complementary resource for the provision of the frequency control ancillary service is made, and a model of causal relationships is established, which allows dividing the participation of demand in frequency regulation in three broad categories. At the same time, a two-stage model is proposed for the design and evaluation of time of use tariff scheme, for the linking of large blocks of the population in the provision of the frequency control ancillary serviceMaestrí

Proceedings of the 8th International Conference on Energy Efficiency in Domestic Appliances and Lighting

At the EEDAL'15 conference 128 papers dealing with energy consumption and energy efficiency improvements for the residential sector have been presented. Papers focused policies and programmes, technologies and consumer behaviour. Special focus was on standards and labels, demand response and smart meters. All the paper s have been peer reviewed by experts in the sector.JRC.F.7-Renewables and Energy Efficienc