# A Methodology for Exploiting Smart Prosumers' Flexibility in a Bottom-Up Aggregation Process
The EMS manages four different phases in the bottom-up aggregation process: configuration, day-ahead management, intra-day management, real-time operation. The main responsibilities of the L-EMS are:  
* Forwarding the data received from the physical gateway to the remote EMS;
* Translating the optimization plans received from the remote EMS into commands to be sent to the devices through the physical gateway;
* Developing a user optimization plan, having a set of basic rules, in case of lack of communication with the remote EMS and, therefore, not being able to participate in an aggregate to respond to the request of the network operator. The main responsibilities of the remote EMS are:* Enhancing, with an internal optimization process (day-ahead), the availability of user flexibility, to be offered through aggregation with other users in response to a request for flexibility by the network operator;
* Determining the aggregate of users and the aggregate offer of flexibility to be proposed to the network operator;
* Trying to keep faith with the flexibility promised if the aggregate is chosen by the network operator for the provision of the grid support service requested, and report in time any impossibility (intraday);
* Carrying out real-time optimization to ensure the promised flexibility in the offer previously made. The controlled switches receive digital or analog commands for changing their status (ON/OFF) depending on the device chosen for that function. The Energy Gateway communicates with the VAE with digital signals. Figure 1: Concept of the system. For understanding the novelty of DEMAND and its potential impact on the exploitation of distributed flexibility, it is important to examine the many solutions and systems for the management of loads and generators connected to the electricity grid that the market offers today. Especially in the industrial and tertiary sectors, these systems generally manage power within microgrids and modulate power absorption or generation towards the DSO. Schneider and Siemens both offer a decentralized SCADA Energy Management System (EMS) to monitor and control loads and generators in order to make the microgrid more efficient, but also to respond to requests from the DSO or energy retailer via OpenADR. General Electric's Grid IQ Microgrid Control System, ABB's Micro Grid Controller 600, Toshiba's \(\upmu\)EMS, PSI Smart Telecontrol Unit and Honeywell's EMS are all very powerful solutions, but essentially proprietary, often working only with devices built by the same manufacturer, inflexible and extremely complex. Open source solutions such as Kiwigrid, Fraunhofer Open Muc and Fraunhofer OGEMA lend themselves well to the implementation of new functions but still have enormous security limitations. None of the solutions mentioned, however, envisages coordination between several users. Distributed logic enabling multi-stakeholder collaboration are not considered. This is due to the fact that these solutions are designed for users whose power consumption/generation levels are already sufficient to guarantee significant effects on the network. All smaller users are excluded from this potential market because they are unable to induce effects on the grid simply by exploiting their limited flexibility. The DEMAND project does not aim to compete with such complex solutions, which are already present in an established market, but to create a solution that enables users to work together, aggregating them in a coordinated and intelligent way, without the need for centralized control. Therefore, the solution will not only be adoptable by industrial and tertiary users, in which it will interface with the internal management systems already present and for which it will represent an innovative extension, but it will also be able to spread to smaller but more numerous residential users.