An Assessment of PIER Electric Grid Research 2003-2014 White Paper

This white paper describes the circumstances in California around the turn of the 21st century that led the California Energy Commission (CEC) to direct additional Public Interest Energy Research funds to address critical electric grid issues, especially those arising from integrating high penetrations of variable renewable generation with the electric grid. It contains an assessment of the beneficial science and technology advances of the resultant portfolio of electric grid research projects administered under the direction of the CEC by a competitively selected contractor, the University of California’s California Institute for Energy and the Environment, from 2003-2014

Achieving energy efficient districts: contributions through large-scale characterization and demand side management.

Buildings are increasingly expected to be more efficient and sustainable since they are essential to energy policies and climate change mitigation efforts. For this reason, it is very important to develop new energy models, with special attention to the residential sector. The present Thesis aims to justify the selection of the district scale as the optimal one to improve the energy performance of the built environment. In this way, renewable energy integration may be increased and innovative approaches such as demand side management may be carried out through the accurate characterization of districts. Several applications are shown to evaluate the solar potentials and the energy demands for entire regions by using 3D city models. The advantages offered by demand side management approaches in buildings and districts are investigated, presenting two applications that benefit from dynamic pricing strategies or the participation in reserve markets. The drawbacks of most current approaches on a large scale are highlighted, and a new tool capable of performing dynamic simulations of whole districts in a user-friendly and accurate way is presented. In addition, a methodology for a proper characterization of districts through monitoring is developed, validated, and used for two applications. The first one characterizes a district consisting of buildings with a limited use of air-conditioning, and the second one evaluates the benefits that could be obtained from the exploitation of the synergies between the buildings of a district. As a last contribution of this Thesis, a new comprehensive methodology for the characterization and optimization of any existing district is proposed.Se espera que los edificios sean cada vez más eficientes y sostenibles, puesto que son esenciales para las políticas energéticas y los esfuerzos hacia la mitigación del cambio climático. Por esta razón, es muy importante desarrollar nuevos modelos energéticos, con especial atención al sector residencial. La presente Tesis parte de que la escala de distrito es la óptima para mejorar el comportamiento de la edificación. Además, permite aumentar la integración de energías renovables y llevar a cabo planteamientos innovadores como la gestión de la demanda a través de una precisa caracterización de los distritos. Se muestran varias aplicaciones para la evaluación de los potenciales solares y las demandas energéticas de regiones enteras, usando modelos 3D de ciudades. Las ventajas ofrecidas por los procedimientos de gestión de la demanda en edificios y distritos también son investigadas, presentando dos aplicaciones que se benefician de estrategias de tarificación dinámica o de la participación en los mercados de reserva. Las desventajas de la mayoría de procedimientos actuales a gran escala también son destacadas, y se presenta una nueva herramienta capaz de llevar a cabo simulaciones dinámicas de distritos completos de forma simple y precisa. Además, se desarrolla una metodología para la caracterización apropiada de distritos a través de monitorización, validada y empleada en dos aplicaciones. La primera trata la caracterización un distrito compuesto por edificios con un uso limitado de la climatización, y la segunda la evaluación de los beneficios que podrían obtenerse de la explotación de las sinergias entre los edificios de un distrito. Como última contribución de la Tesis, se propone una nueva metodología completa para la caracterización y optimización de cualquier distrito existente.Premio Extraordinario de Doctorado U

Proceedings of the Australian Summer Study on Energy Productivity

This collection includes the peer-reviewed papers presented during the 2016 Australian Summer Study on Energy Productivity

Ancillary Services in Hybrid AC/DC Low Voltage Distribution Networks

In the last decade, distribution systems are experiencing a drastic transformation with the advent of new technologies. In fact, distribution networks are no longer passive systems, considering the current integration rates of new agents such as distributed generation, electrical vehicles and energy storage, which are greatly influencing the way these systems are operated. In addition, the intrinsic DC nature of these components, interfaced to the AC system through power electronics converters, is unlocking the possibility for new distribution topologies based on AC/DC networks. This paper analyzes the evolution of AC distribution systems, the advantages of AC/DC hybrid arrangements and the active role that the new distributed agents may play in the upcoming decarbonized paradigm by providing different ancillary services.Ministerio de Economía y Competitividad ENE2017-84813-RUnión Europea (Programa Horizonte 2020) 76409

Fast-timescale Control Strategies for Demand Response in Power Systems.

Concerns over climate change have spurred an increase in the amount of wind and solar power generation on the grid. While these resources reduce carbon emissions, the physical phenomena that they rely on - wind and sunlight - are highly stochastic, making their generated power less controllable. Demand-side strategies, which modulate load in a controllable manner, have been proposed as a way to add flexibility to the grid. Resources with innate flexibility in their load profile are particularly suited to demand response (DR) applications. This work examines two such loads: heating, ventilation, and air conditioning (HVAC) systems, and plug-in electric vehicle (PEV) fleets. HVAC systems can vary the timing of power consumption due to the thermal inertia inherent in their associated building(s). The first part of this thesis explores the efficacy of using commercial HVAC for DR applications. Results are presented from an experimental testbed that quantify performance, in terms of accuracy in perturbing the load in a desired manner, as well as the efficiency of this process. PEVs offer very fast response times and may eventually represent a significant load on the power system. The second part of this thesis develops several control strategies to manage PEV power consumption in an environment where communication resources are limited, both to prevent detrimental system effects such as transformer overload, and to provide ancillary services such as frequency regulation to the grid.PhDElectrical Engineering: SystemsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/116627/1/ianbeil_1.pd

Predictive Energy Management of Islanded Microgrids with Photovoltaics and Energy Storage

Islanded microgrids powered primarily by photovoltaic (PV) arrays present a challenging control problem due to the intermittent production and the relatively close scale between the sources and the loads. Energy storage in such microgrids plays an important role in balancing supply with demand, and in extending operation during periods when the PV supply is not available or insufficient. The efficient operation of such microgrids requires effective management of all resources. A predictive energy management strategy can potentially avoid or effectively mitigate upcoming outages. This thesis presents an energy management system (EMS) for such microgrids. The EMS uses a predictive approach to set operational schedules in order to (a) prolong the supply to critical system loads and (2) minimize the chances and duration of system-wide outages, specifically through pre-emptive load shedding. Online weather forecast data has been combined with the PV system model to assess potential energy production over a 48 hour period. These predictions, along with load forecasts and a model of the energy storage system, are used to predict the state-of-charge of the storage devices and characterize potential power shortages. Pre-emptive load shedding is subsequently planned and executed to avert outages or minimize the duration of unavoidable outages. A bounding technique has also been proposed to account for uncertainties in estimates of the stored energy. The EMS has been implemented using an event-driven framework with network communication. The approach has been validated through simulations and experiments using recorded real-world solar irradiance data. The results show that the outage durations have been reduced by a factor of 87% to 100% for an example operating scenario, selected to demonstrate the features of the scheme. The impact of uncertainties in the prediction models has also been investigated, specifically for the PV system rating and the battery capacity. A technique has been developed to compensate for such uncertainties by analyzing the data streams from the source and storage units. The technique is applied to the developed EMS strategy, where it is able to shorten the total outage duration by a factor of 12% over a 42-day scenario exhibiting a variety of irradiance conditions