A review of microgrid development in the United States – A decade of progress on policies, demonstrations, controls, and software tools

Microgrids have become increasingly popular in the United States. Supported by favorable federal and local policies, microgrid projects can provide greater energy stability and resilience within a project site or community. This paper reviews major federal, state, and utility-level policies driving microgrid development in the United States. Representative U.S. demonstration projects are selected and their technical characteristics and non-technical features are introduced. The paper discusses trends in the technology development of microgrid systems as well as microgrid control methods and interactions within the electricity market. Software tools for microgrid design, planning, and performance analysis are illustrated with each tool's core capability. Finally, the paper summarizes the successes and lessons learned during the recent expansion of the U.S. microgrid industry that may serve as a reference for other countries developing their own microgrid industries

Assessment of Haiti’s electricity sector

INTRODUCTION: This report summarizes the current state of the electricity sector in Haiti, to form a knowledge base from which to subsequently evaluate options for how best to increase electricity access in Haiti. Accordingly, this report summarizes the results of an extensive review of the publicly-available information on the electricity sector in Haiti, supplemented by targeted interviews with selected individuals known to be knowledgeable about electricity in Haiti based on their recent involvement in assessing the sector or in pursuing/supporting development opportunities. [TRUNCATED

Software Defined Networks based Smart Grid Communication: A Comprehensive Survey

The current power grid is no longer a feasible solution due to ever-increasing user demand of electricity, old infrastructure, and reliability issues and thus require transformation to a better grid a.k.a., smart grid (SG). The key features that distinguish SG from the conventional electrical power grid are its capability to perform two-way communication, demand side management, and real time pricing. Despite all these advantages that SG will bring, there are certain issues which are specific to SG communication system. For instance, network management of current SG systems is complex, time consuming, and done manually. Moreover, SG communication (SGC) system is built on different vendor specific devices and protocols. Therefore, the current SG systems are not protocol independent, thus leading to interoperability issue. Software defined network (SDN) has been proposed to monitor and manage the communication networks globally. This article serves as a comprehensive survey on SDN-based SGC. In this article, we first discuss taxonomy of advantages of SDNbased SGC.We then discuss SDN-based SGC architectures, along with case studies. Our article provides an in-depth discussion on routing schemes for SDN-based SGC. We also provide detailed survey of security and privacy schemes applied to SDN-based SGC. We furthermore present challenges, open issues, and future research directions related to SDN-based SGC.Comment: Accepte

Multi-user microgrids: obstacles to development and recommendations for advancement

EXECUTIVE SUMMARY: Multi-user microgrids (MUMs) are an emerging approach to electricity service that allows neighboring customers to obtain greater resilience in electricity service, from a set of locally installed distributed energy resources (DERs) of their own choice (sometimes including solar energy and energy storage), through joint participation in a power production and delivery system that can operate independently from the host electric utility. To date, there are relatively few MUMs in operation. This is primarily because regulated utility service from the electricity grid has historically been adequate and cost-effective for most customers – and it is highly likely that this will remain largely true, so that MUMs will not become widespread anytime soon. However, with improving microgrid economics and increasing customer needs for resilience, there will be a growing number of situations in which MUMs will become viable. Even today, certain sets of customers find the benefits offered by MUMs to outweigh the additional costs. Despite this, MUM activity has been extremely limited because of a number of significant barriers associated with implementing this novel business model. Exacerbating this, there is a dearth of comprehensive study on these barriers. Consequently, the goal of this research is to provide a first investigation into the barriers to MUM development and some early hypotheses on potential remedies that would facilitate MUM development when and where they might be a good solution – with a particular focus on the Northeastern U.S. [TRUNCATED]Funding for this research was provided via a generous gift from E4TheFuture

Energy Management Strategies in hydrogen Smart-Grids: A laboratory experience

As microgrids gain reputation, nations are making decisions towards a new energetic paradigm where the centralized model is being abandoned in favor of a more sophisticated, reliable, environmentally friendly and decentralized one. The implementation of such sophisticated systems drive to find out new control techniques that make the system “smart”, bringing the Smart-Grid concept. This paper studies the role of Energy Management Strategies (EMSs) in hydrogen microgrids, covering both theoretical and experimental sides. It first describes the commissioning of a new labscale microgrid system to analyze a set of different EMS performance in real-life. This is followed by a summary of the approach used towards obtaining dynamic models to study and refine the different controllers implemented within this work. Then the implementation and validation of the developed EMSs using the new labscale microgrid are discussed. Experimental results are shown comparing the response of simple strategies (hysteresis band) against complex on-line optimization techniques, such as the Model Predictive Control. The difference between both approaches is extensively discussed. Results evidence how different control techniques can greatly influence the plant performance and finally we provide a set of guidelines for designing and operating Smart Grids.Ministerio de Economía y Competitividad DPI2013-46912-C2-1-

WE ARE ALL GONNA DIE: HOW THE WEAK POINTS OF THE POWER GRID LEAVE THE UNITED STATES WITH AN UNACCEPTABLE RISK

Federal regulations aim to ensure grid reliability and harden it against outages; however, widespread outages continue. This thesis examines the spectrum of regulations to evaluate them. It outlines their structure, the regulations’ intent, and weighs them against evolving cyber and physical threats and natural disaster risks. Currently, the regulatory structure is incapable of providing uniform security. Federal standards protect only the transmission portion of the grid, leaving the distribution section vulnerable to attack due to varying regulations from state to state, or county to county. The regulations cannot adapt quickly enough to meet dynamic threats, rendering them less effective. Cyber threats can be so agile that protectors are unaware of vulnerabilities, and patching requirements are too lengthy, which increases the risk exposure. No current weather mitigation or standard is capable of protecting the grid despite regular natural disasters that cause power shutdowns. The thesis concludes that bridging these gaps requires not increasing protection standards, but redundancy. Redundancy, mirrored after the UK's infrastructure policy, is more likely to reduce failure risk through layered components and systems. Microgrids are proven effective in disasters to successfully deliver such redundancy and should be implemented across all critical infrastructure sectors.Civilian, Department of Homeland SecurityApproved for public release. Distribution is unlimited

Lessons from last mile electrification in Colombia: Examining the policy framework and outcomes for sustainability

More than a decade ago, Colombia reached a 95% electrification rate. Despite efforts from multiple actors, including government, private sector companies, communities and donors, this rate has only barely improved. In 2020, around 1.9 million Colombians – all residing in rural areas – lacked access to electricity. The electrification challenge is compounded by the geographical isolation of these last mile communities, which makes interconnection to the national electricity grid infeasible. Even where off-grid communities do have access to electricity, supply is often limited to less than six hours per day raising questions about the adequacy of provision. This paper investigates last mile electrification in Colombia, specifically examining the policy framework and the outcomes for the sustainability of last mile projects. Drawing on document analysis, expert interviews and case studies, this paper finds that the government has created an overly complex policy environment which hinders rather than facilitates electrification efforts. It also continues prioritizing the use of diesel generators through costly supply-side subsidies, resulting in high operating costs and inadequate service. More recently, although renewable sources have shown good outcomes, for instance in the case studies examined here, these experiences have not been extensible disseminated. Finally, this paper argues that changes are required to the institutional framework to deliver electricity to last mile communities in Colombia. Specifically, if the multidimensional benefits of electricity are to be realized, changes will need to include improvements in public infrastructure to promoting intersectoral work that promotes socio-economic development of last mile communities and beyond

Energy storage sizing for low-inertia microgrids, and lessons learned from a potential microgrid

The coordinated control of multiple distributed generators in a microgrid and the preservation of adequate system inertia in real-time operations are some of the principal technical challenges for stable microgrid operation. One issue in particular pertains to grid-tied inverters, which, as mandated by present standards, are only permitted to operate at unity power factor, thereby requiring the microgrid’s synchronous generators to operate at a low power factor. This behavior accordingly introduces ramifications by limiting the generator’s active power output, which would compromise frequency and voltage stability margins. Consideration is also given to the effect of line impedances, since interconnecting microgrid lines can be described by a variety of X/R ratios that affect the control and flow of active and reactive power. Moreover, the absence of a stiff grid presents control challenges for grid-tied inverters due to the inverters’ tendency to regulate the voltage at the point of common coupling. These same inverters also jeopardize microgrid stability due to their low equivalent inertia as traditional forms of generation (i.e., spinning sources) become displaced by inertia-less inverters. Because of this low microgrid inertia, fluctuations in the output power of renewable energy sources or changes in local load levels may lead to power quality or frequency/voltage stability concerns. Therefore, energy storage sizing is investigated in this dissertation, as it is closely related to the stability analysis of microgrids. Furthermore, an existing residential community (in Austin, TX) described by a moderate penetration of photovoltaic sources and electric vehicle charging is considered, and the implications of said community being retrofitted to a microgrid are examined.Electrical and Computer Engineerin