## 3 Features and Advantages of Smart Grid
Key parameters to address the discrepancies are currently being studied using different prediction technologies. Other aspects of the distributed generations are Grid to Vehicle (G2V) and Vehicle to Grid (V2G). In G2V, Electric Vehicles (EVs) are generally fueled by charging it from an energy reserve system such as a battery storage system which is charged by an external energy source such as PV, utility grid or other energy systems. However, the uncoordinated charging operation of vehicle fleet may introduce a momentary spike as new load into the grid system. One solution to this disadvantageous effect is to optimize the charging profile of EVs in a coordinated manner so that not all vehicles are charged at one time [30]. Reference [47] showed that charging EVs in a coordinated manner could reduce losses in system power and deviations in system voltage by smoothing power during the peak time. In V2G, EVs are capable to deliver electricity to the utility given that the EVs are parked and have a secure connection with the utility grid. The advantage of power supplied by EVs is that it can help in balancing the loads during \"peak shaving\". In [48], a particle swarm optimization method has been applied to identify the optimal solutions to escalate the benefits of the vehicle owners considering the practical constraints of the system. The block diagram of V2G and G2V is represented in Figure 5[49]. * GHG Emission Reduction: Smart grid can certainly help in reducing greenhouse gas emission by accommodating a large number of renewable power generations. It is indicated in the IEA report that 50% of the gas emission has to be reduced by 2030 from the energy efficiency point of view. It is also indicated that about one quarter of the gas emission can be reduced by integrating renewable energy sources and bio-fuels, while 10% of the emission could be reduced using nuclear, carbon capture, and storage system [50]. Using wind or solar based distributed generators can be an effective solution in meeting with the profuse demand of electricity as well as reducing the GHG emission. However, integration of renewable power generations to the utility grid becomes more challenging for increasing the level of penetration from renewable power. The main challenges of solar and wind energy are intermittence and fluctuant of the energy, which causes voltage fluctuation; low capacity factors (the typical capacity factor for PV 10%-20% and for wind 20%-40%); lack of correlation with the load profiles; relatively large forecast errors and more complicated; congestion in power transmission due to large scale system installations; congestion in distribution grid due to distributed renewable resources. Introduction of energy storages into the power network can minimize such problems. In addition, application of Demand Response (DR) concept can further reduce such problems. Hence, an integration of distributed generation, distributed energy reserve, and DR can be utilized for SG development to tackle the issues suffered by the power network. * Bi-directional Communication System: Bi-directional communication system has already been being used in many areas including oil and gas plant monitoring and control. This two-way communication technology has the potential to utilize in monitoring and controlling the SG network centrally. * Automatic Healing Capability (AHC): Automatic healing capability of a SG is very essential for its reliable and efficient operation. Smart grid with this feature can automatically detect the abnormal scenarios such as over current, over and under frequency, voltage surge, fault current etc. in the network. Such information can be sent to the SG control center to initiate automatic recovery/healing of the system for a particular abnormal scenario. Bi-directional communication system may increase the operational performance of the SG by providing more controllability, whereas AHC increases the efficiency and power quality (PQ) of the SG. Both of these systems are very important for improving the performance of SG.