Load Balancing with Energy Storage Systems Based on Co-Simulation of Multiple Smart Buildings and Distribution Networks

In this paper, we present a co-simulation framework that combines two main simulation tools, one that provides detailed multiple building energy simulation ability with Energy-Plus being the core engine, and the other one that is a distribution level simulator, Matpower. Such a framework can be used to develop and study district level optimization techniques that exploit the interaction between a smart electric grid and buildings as well as the interaction between buildings themselves to achieve energy and cost savings and better energy management beyond what one can achieve through techniques applied at the building level only. We propose a heuristic algorithm to do load balancing in distribution networks affected by service restoration activities. Balancing is achieved through the use of utility directed usage of battery energy storage systems (BESS). This is achieved through demand response (DR) type signals that the utility communicates to individual buildings. We report simulation results on two test cases constructed with a 9-bus distribution network and a 57-bus distribution network, respectively. We apply the proposed balancing heuristic and show how energy storage systems can be used for temporary relief of impacted networks

Dynamic Modeling and Optimal Design for Net Zero Energy Houses Including Hybrid Electric and Thermal Energy Storage

Net zero energy (NZE) houses purchase zero net metered electricity from the grid over a year. Technical challenges brought forth by NZE homes are related to the intermittent nature of solar generation, and are due to the fact that peak solar generation and load are not coincident. This leads to a large rate of change of load, and in case of high PV penetration communities, often requires the installation of gas power plants to service this variability. This article proposes a hybrid energy storage system including batteries and a variable power electric water heater which enables the NZE homes to behave like dispatchable generators or loads, thereby reducing the rate of change of the net power flow from the house. A co-simulation framework, INSPIRE+D, which enables the dynamic simulation of electricity usage in a community of NZE homes, and their connection to the grid is enabled. The calculated instantaneous electricity usage is validated through experimental data from a field demonstrator in southern Kentucky. It is demonstrated that when the operation of the proposed hybrid energy storage system is coordinated with solar PV generation, the required size and ratings of the battery would be substantially reduced while still maintaining the same functionality. Methodologies for sizing the battery and solar panels are developed

Net Zero Energy Houses with Dispatchable Solar PV Power Supported by Electric Water Heater and Battery Energy Storage

Over a year, net zero energy (NZE) houses produce and feed zero net metered electrical energy to the grid. Technical challenges, notably the `duck curve\u27 arise due to the fact that peak solar generation and load demand are seldom coincident. Common approaches to mitigate this limitation include the curtailment of solar power, and the use of storage. Surplus solar energy may be stored in a battery, which can subsequently be discharged to supply the home electricity needs when demand is in excess. In addition to batteries, less expensive electric water heaters, which are ubiquitous, can be modified as energy storage systems, functioning as `uni-directional batteries\u27 by virtue of their high thermal mass. This paper proposes the use of a hybrid energy storage system including both batteries and variable power electric water heaters in NZE residences. It is demonstrated that the hybrid energy storage system along with solar PV generation coordinated and virtual power plant (VPP) controls would reduce the required battery size and ratings while still harvesting the maximum solar energy potential. The proposed control strategy enables the NZE homes to produce dispatchable power or behave like controllable loads, and benefits at the utility level are demonstrated by interconnection of NZE homes with an IEEE 13 node test feeder system. The technology has the potential to mitigate all issues related to solar power variability

A Case for Using Distributed Energy Storage for Load Balancing and Power Loss Minimization in Distribution Networks

Abstract—We introduce an algorithm to solve the problem of load balancing and loss minimization in distribution networks impacted by temporary service restoration activities. The novelty of the proposed algorithm lies in employing utility directed usage of customer distributed battery energy storage systems, which are assumed to be present and available in the network. With increasing penetration of distributed renewable energy sources, such as photovoltaics and wind turbines, it is projected that batteries will also increasingly be adopted to address some of the new challenges with renewables, such as the so-called duck curve challenge. The deployment of the proposed solution is achieved through demand response signals. To verify its benefits, we develop a co-simulation framework which can be used to develop and study distribution level optimization techniques that exploit the interaction between a smart electric grid, smart buildings and distributed energy storage to achieve energy and cost savings and better energy management practices beyond what one can achieve through techniques applied at the building or network levels only. The proposed algorithm is implemented and verified within the co-simulation framework tool, SmartBuilds. Simulations show that energy storage systems can be used for temporary relief of distribution networks impacted by line failures

SmartBuilds: An Energy and Power Simulation Framework for Buildings and Districts

We introduce a district level multiple buildings energy and power simulation framework. At the building level, the proposed simulation framework, SmartBuilds, leverages Energy-Plus as the core simulation engine for building energy assessment, thereby benefiting from the capabilities of a widely accepted and used state-of-the-art modeling tool. Building models may include batteries for energy storage and renewable energy generators: PV arrays and wind turbines. At the district level, one of the main goals is to provide a versatile platform for the simulation and optimization of the interaction between the electric grid and buildings as well as of the interaction between buildings. Because buildings can participate in intelligent social-like activities through which energy tokens/budgets can be exchanged, the tools provides collective optimization opportunities beyond the usual techniques applied at building level. The paper introduces SmartBuilds\u27 architecture and demonstrates its usefulness in scenarios where multiple buildings are simulated concurrently to asses and seek operating schedules for battery energy storage systems that minimize the overall energy consumption at the district level

Open Source Digital Camera on Field Programmable Gate Arrays

We present an open source digital camera implemented on a field programmable gate array (FPGA). The camera functionality is completely described in VHDL and tested on the DE2-115 educational FPGA board. Some of the current features of the camera include video mode at 30 fps, storage of taken snapshots into SDRAM memories, and grayscale and edge detection filters. The main contributions of this project include 1) the actual system level design of the camera, tested and verified on an actual FPGA chip, and 2) the public release of the entire implementation including source code and documentation. While the proposed camera is far from being able to compete with commercial offerings, it can serve as a framework to test new research ideas related to digital camera systems, image processing, computer vision, etc., as well as an educational platform for advanced digital design with VHDL and FPGAs