"Mafate Micro Grid" is a research project funded by the European Regional Development Fund and held by a partnership between the PIMENT Laboratory of the Reunion Island University and the SIDELEC Reunion. The main purpose of the project is to develop and improve smart grid concept in Reunion Island. Mafate is a landlocked area non-connected to the main electrical grid. A major stake for local authorities is to electrify about 300 homes by means of solar microgrid installations. Our case study provides an actual Energy Management System application for 3 homes in Mafate, aiming to maximize the use of photovoltaic energy and to prolong battery life. The project is carried out closely with three Mafate homes, as a human-machine interface is installed in each house. This work is a preliminary approach to evaluate theoretically the effectiveness of a Demand Side Management process depending on the users' acceptability. Results show the Energy Management System reduces energy wastes and increases the solar energy effectively used, provided users follow the given advice.