Optimum operation of a real renewable smart energy system including thermal electric and hydro storages

Smart energy systems are meant as groups of energy conversion units that fulfill the requirements of several users’ demands exploiting the available energy sources according to “smart rules”. This paper considers a smart energy system composed by both programmable units (hydroelectric plant, bio-oil and bio-gas internal combustion engines and woodchip boilers) and a non-programmable photovoltaic unit, which serve a group of users (houses, hotels, shops, craft workshops and industries) that requires thermal energy and electricity. The choice of the type and size of the system units was previously made according to government incentives on renewable energy production and historical data of users’ demands. Off-design models of each unit are built to properly simulate the system behavior starting from nameplate data supplied by the manufacturers and measured data from the field. A general optimization approach is then applied to search for the optimum operation of the total system, which maximizes the profit deriving from selling/using the generated electricity and thermal energy. The capacities of thermal and electric storages are also an outcome of the optimum operating strategy of the total system: results show that the optimum operation strategy can be achieved by including a thermal storage to reduce the use of boilers, while the inclusion of an electric storage is disadvantageous.