## 5 The Evolution towards a Global Smart Grid Deployment: Challenges and Perspectives
### Evolution and Adaptability of MGs towards a SG Scenario
#### 5.2.2 Towards a Multi-Generation Scenario  
Smart Power Grids constitute a new paradigm of electrical networks not only for the employ of new intelligent management systems, but also for the convergence of different energy sources, with an important role of renewable energies and microgrids. Nevertheless, in the near future, more complex interactions between different generation sources must be considered, as shown in Figure 8.  
The Multi Energies Systems (MESs), including the production of electricity, heat, cooling, fuels and even transportation are expected to offer new optimization possibilities [110]. In a MES, storage problems can be cleared up applying all the possible energy conversions. For instance, depending on the scenario, it could be possible to store energy in thermal form (high temperature for heating or low temperature for cooling) combined with classical electrical energy storage. Nowadays, some generation solutions based on interactions between different technologies already exist: combined heat and power (CHP), electric heat pumps (EHP), air conditioning devices, and trigeneration systems (electricity, heat and cooling). CHP is the most studied by the scientific community in various environments: Smart Grids [111], microgrids [112] or smart cities [113; 114].  
Multi energies experimental test plants have been installed around the world to demonstrate their economic and environmental benefits. One example is the Smart Polygeneration Microgrid of the University of Genoa, composed by CHP units, natural gas boilers, thermal storage, absorbing chiller,  
Figure 8: Structure of a “multi-generation” MG scenario.  
a concentrated solar power unit coupled to Stirling engines, electrical storage, photovoltaic panels and recharging stations for electrical vehicles [115]. The optimal daily operation of the system is assured by an operation center that utilizes mathematical models. Other mathematical models are used to optimally design a MES, as the mixed-integer linear programming super-structure model proposed in [116]. The objective is to minimize the overall investment cost and the operating price of the system.  
In summary, the real challenge is to make possible the convergence and the complete association of all those energy networks, achieving a correct interoperability. The task is complex considering that the management methods to be applied are quite different. Communication technologies and WSANs will be two of the fundamental points of this future \"Super Grid\", and the geographical structuration using the microgrid concept can be a solution to limit the quantity of overall data exchange. In this way, a large amount of information will be used only inside the MG for its own management. The SG implementation is based on extraordinary data storage and computation capabilities. In this context, Cloud Computing, thanks to its key characteristics (flexible resources and services shared in network, parallel processing and quasi-omnipresent access), will have an important role to play in the future SG [117].