# On Hybrid Nanogrids Energy Management Systems--An Insight into Embedded Systems
## 3 Nanogrid EMS  
### Overview of EMSs  
The International Electrotechnical Commission, in its IEC 61970 standard on the application program interface of EMSs in power system management (version 1.1 or later), defines EMSs as follows: \"a computer system comprising a software platform providing basic support services and a set of applications providing the functionality needed for the effective operation of electrical generation and transmission facilities so as to assure adequate security of energy supply at minimum cost\" [64]. A nanogrid EMS consists of software and hardware systems used to monitor, control, and optimize the generation, storage, and distribution of energy within the nanogrid. It ensures efficient and reliable  
Figure 3: Structure of a hybrid nanogrid. energy flow, maximizes energy utilization, and reduces energy waste. The EMS is responsible for real-time energy monitoring, load forecasting, and energy scheduling to minimize energy costs and improve overall grid stability. An EMS also includes communication protocols for exchanging data with other components of the nanogrid. Many studies have been conducted in this emerging field, and some research shows the use of hybrid energy in embedded systems. As shown in Figure 4, a nanogrid EMS performs a number of tasks, including the monitoring, analysis, and forecasting of power generation and load consumption, taking into account energy market pricing, ancillary market prices, and meteorological data. These features support EMS in maximizing MG performance while respecting the technical limitations. A building energy management system has been developed with the objective of adjusting consumption to the available energy resources while maximizing the comfort of the inhabitants. It is modeled as an integer mixed linear problem model consisting of several binary and continuous variables, constraints, and an objective function to be minimized [65]. A comparison is made between several solution approaches for the optimization of multi-source and multi-client power flows. This study is directed towards a hybrid centralized solution: a central system receives information from all the equipment and controls it [66]. This approach is further studied, where the optimization is based on the different operating modes of the electrical equipment, the preferences of the users, and also the electricity prices. The electrical equipment is thus divided into three categories: permanent, which runs over the whole horizon, like the freezer; temporary, which needs a specific request to run; and unsupervised, which is not managed by the EMS. In this study, two different approaches are proposed to design the energy management system: the non-centralized approach (multi-agent systems), adopting a distributed architecture and resolution through cooperation between the different agents of the system and the exchange of information between them, and the centralized approach, which is a linear formulation of the problem to be optimized [40]. A human-machine interface with an EMS has been designed in G-homeTech and aims to make substantial savings by avoiding consumption during peak prices for buildings [67]. A study is carried out to identify energy efficiency measures and innovative technologies to ensure that the energy efficiency of buildings is maximized while meeting the needs of the occupants [68]. A linear system for building energy management has been designed with the aim of minimizing the cost of electricity while satisfying the thermal comfort constraint [69]. A farm design consisting of a combination of wind turbines, tidal turbines, diesel generators, and pumped hydro storage was developed while compromising the overall cost of the system for a 15-year period and the minimization of CO2 emissions. This renewable  
Figure 4: Nanogrid EMS functions. energy farm is dedicated to energy production in a self-sufficient marine context [70].