Nanogrid: An Introduction

Renewable & Sustainable Energy Reviews, 2017

The centralised power grid bears a heavy burden in a time when consumers expect an uninterrupted reliable power supply, a reduction in carbon emissions, increased efficiency within the national grid and power supplied to remote communities. As expectations increase, it becomes the task of power systems research and design to develop new structures to meet these demands. This has led to alternatives being sought for centralised power generation, which is prone to outages (due to long distance transmission), is a substantial contributor to global carbon emissions, has large transmission losses and is often not a practical solution when supplying remote communities. Distributed generation (DG) looks to remedy these inadequacies by producing power close to its point of consumption, often utilising carbon neutral, renewable energy (RE) sources (sun, wind). To maximise the efficient use of DG, control structures are used to balance the intermittent RE power production with consumer power consumption. One such structure is used to implement control of small scale DG, at a single house/small building level: the nanogrid. This paper explores the current nanogrid research, it collates the existing definitions and uses the knowledge to give a concise definition of a nanogrid. It then discusses the control topologies and techniques which enable the intelligent control of the nanogrid, before presenting the hardware platform used to ensure the efficient operation of a small scale DG system. The paper then considers the interconnection of multiple nanogrids forming a network (microgrid), facilitating the sharing of power between individual nanogrids. The future developments are then explored before the paper's conclusions are presented.

Microgrid is a new technology in power generation and this system is used to provide power and heat to its local area, such as cogeneration systems and renewable energy (wind turbines, photovoltaic cells, etc.). They are preferred for medium or high power applications. Nanogrid most likely to be used in small local loads for rural area as they will be more economic then the normal grid power system. Nano grids can operate independently or be connected to the mains and most likely the internal voltage can be utilized as ac or dc. In this research paper a small scale microgrid system is proposed for smart homes called "Nanogrid". Each houses have small electrical power system from them can be shared among houses. If it uses a DC system instead of a general AC system, it can reduce energy loss of inverter because each generator doesn't need an inverter. Furthermore, it can continue to provide a power supply when blackout occurs in the bulk power system. A model of a nanogrid is developed to simulate the operation of the centralized power control. Finally a Simulink model is presented for small houses power range 90-285 KW.

Sustainability

Environmental issues and the global need to extend sustainable access to electricity have fostered a huge amount of research in distributed generation by renewables. The challenges posed by the widespread deployment of distributed generation by renewables, such as intermittent power generation, low inertia, the need for energy storage, etc., call for the development of smart grids serving specific local areas or buildings, referred to as microgrids and nanogrids, respectively. This has led in the last decades to the proposal and actual implementation of a wide variety of system architectures and solutions, and along with that the issue of the power converters needed for interfacing the AC grid with DC micro- or nanogrids, and for DC regulation within the latter. This work offers an overview of the state of the art of research and application of nanogrid architectures, control strategies, and power converter topologies.

Energies, 2021

Distributed generation (DG) systems are growing in number, diversifying in driving technologies and providing substantial energy quantities in covering the energy needs of the interconnected system in an optimal way. This evolution of technologies is a response to the needs of the energy transition to a low carbon economy. A nanogrid is dependent on local resources through appropriate DG, confined within the boundaries of an energy domain not exceeding 100 kW of power. It can be a single building that is equipped with a local electricity generation to fulfil the building’s load consumption requirements, it is electrically interconnected with the external power system and it can optionally be equipped with a storage system. It is, however, mandatory that a nanogrid is equipped with a controller for optimisation of the production/consumption curves. This study presents design consideretions for nanogrids and the design of a nanogrid system consisting of a 40 kWp photovoltaic (PV) syst...

Energies, 2019

I started hearing a lot about energy digitization a little over a year ago, talking to my colleagues during conferences and meetings [...]

IEEE Access, 2018

Low-inertia power generation units make nanogrids vulnerable to the voltage and power fluctuations caused by pulse loads and abnormal grid conditions. The conversion of critical loads to smart loads is a potential solution for improving the stability and power quality in nanogrids. This paper investigates the effects of utilizing smart loads on the performance of nanogrids. A smart load can compensate for sudden deviations between supply and demand, and therefore, can mitigate voltage and power oscillations in low-inertia nanogrids. The conversion of critical loads to smart loads can reduce the stress on energy storage units and minimize the required battery banks in nanogrids. In this paper, several case studies are considered to verify the stability and power quality improvement of nanogrids when some loads are converted to smart loads.

-The use of renewable energy is essential to reduce the consumption of final energy used in the residential and tertiary sectors. For their effective integration in buildings, the main obstacles to be overcome are the design of multi-source systems (where renewable sources coexist with conventional sources), their design and their control-command. The objective is to obtain an optimal system from an economic and energy point of view. Because of the spread of the use of renewable energy to achieve energy self-sufficiency in remote areas, microgrids can lead to sustainable development of clean power systems but they pose challenges to a reliable energy supply because of its intermittent nature. This article presents a microgrid model including a PV. The purpose of the energy management system (EMS) is to provide a reliable and optimal generation from multiple sources in the microgrid. The idea is based on exchanging intermittent energy between the houses of a local community. Each house is equipped with an AC nanogrid including photovoltaic panels. These nanogrids are equipped with a network controller that the power can be exchanged between the houses on an external AC power bus. In this way, the fluctuations in response to demand are absorbed between nanogrid to improve reliability, energy management and complementarity nanogrids.

Energies

The massive expansion of Distributed Energy Resources and schedulable loads have forced a variation of generation, transmission, and final usage of electricity towards the paradigm of Smart Communities microgrids and of Renewable Energy Communities. In the paper, the use of multiple DC microgrids for residential applications, i.e., the nanogrids, in order to compose and create a renewable energy community, is hypothesized. The DC Bus Signaling distributed control strategy for the power management of each individual nanogrid is applied to satisfy the power flow requests sent from an aggregator. It is important to underline that this is an adaptive control strategy, i.e., it is used when the nanogrid provides a service to the aggregator and when not. In addition, the value of the DC bus voltage of each nanogrid is communicated to the aggregator. In this way, the aggregator is aware of the regulation capacity that each nanogrid can provide and which flexible resources are used to provi...

More than a billion people worldwide still do not have access to basic modern energy services such as electric lighting in their homes. Most of these people live in remote rural areas, which makes extension of national electric grids to meet their needs prohibitively expensive. Several solutions involving solar photovoltaic electricity generation, such as solar lanterns, solar home systems (SHS), and solar (AC) mini-grids are being actively pursued to address the energy requirements of these people. These current solutions each have certain limitations, such as high cost for the cases of minigrids and solar home systems, or limited functionality and expandability in the case of solar lanterns. This work describes an approach to rural electrification – solar DC nano-grids – which attempts to address these limitations by providing basic energy services at lowest possible cost, while using a system architecture which is expandable and future-proof.

Energies, 2024

In the context of an insulated area with a subtropical climate, such as La Réunion island, it is crucial to reduce the energy consumption of buildings and develop local renewable energy sources to achieve energy autonomy. Direct current (DC) nanogrids could facilitate this by reducing the energy conversion steps, especially for solar energy. This article presents the deployment and efficiency evaluation of a 48 VDC low-voltage direct current (LVDC) nanogrid, from conception to real-world installation within a company. The nanogrid consists of a photovoltaic power plant, a lithium-iron-phosphate (LFP) battery, and DC end-use equipment, such as LED lighting and DC fans, for two individual offices. For identical test conditions, which are at an equivalent cabling distance and with the same final power demand, the total power consumed by the installation is measured for several stages from 50 to 400 W, according to a 100% DC configuration or a conventional DC/AC/DC PV configuration incorporating an inverter and AC/DC converter. The methodology used enables a critical view to be taken of the installation, assessing both its efficiency and its limitations. Energy savings of between 23% and 40% are measured in DC for a power limit identified at 150 W for a distance of 25 m. These results show that it is possible to supply 48 VDC in an innovative way to terminal equipment consuming no more than 100 W, such as lighting and air fans, using the IEEE 802.3 bt power over ethernet (PoE) protocol, while at the same time saving energy. The nanogrid hardware and software infrastructure, the methodology employed for efficiency quantification, and the measurement results are described in the paper.