Building stock simulation to support the development of a district multi-energy grid

Abstract

The urbanization process is constantly increasing worldwide. Today over 50 % of the population resides in urban areas and this value is expected to grow up to 68 % by 2050. In this scenario, the development of district scale energy grids and management systems has become crucial to optimize energy use and to balance energy flows within the cities, encouraging the use of renewable sources and self-consumption. This study focusses on a district under development in the city of Milan, involving an urban area of about 920 000 m2, which, once completed, will count for about 4 500 apartments, a school and a few other commercial uses. The existing energy systems consist of an electric grid, including a small photovoltaic field, a district heating system and a local district cooling system exploiting groundwater via heat pumps. They serve, at present, seven residential tower buildings (400 apartments). The overarching aim of the research is to evolve the existing grid into a smart energy grid able to guarantee an intelligent management of the district, empowering eventually people to apply for demand-response schemes, electric mobility and other innovative services. In order to perform such an improvement and extension of the exiting grid, it is necessary to evaluate and simulate the profiles and dynamics of the final energy uses for the residential buildings, that will represent the major load on site. Since monitoring data are not yet available for the district, the evaluation of the energy performance of the existing buildings has been developed through dynamic energy simulations via the definition of profile loads of the most frequent apartment typologies, that allow, moreover, to simulate further developments in the districts. Besides, a monitoring plan for the existing systems has been developed and implemented. Monitoring data will be used at first for validating the developed load profiles; then, they will be analysed to develop optimisation algorithms for the management of the upgraded energy grid. In this paper, the case study is presented and the results of the analysis, via energy simulation, on the existing building stock are reported.

Neighborhood Energy Modeling and Monitoring: A Case Study

“…The profiles have then been multiplied for the average value of electric energy use and the number of people for each apartment typology. These values have been derived from the same database used for the profiles generation (Table 5) [23].…”

“…The current challenge of applied research relates to the management of groups of buildings together, in order to improve the overall efficiency of a neighborhood and its integration with the city's energy networks (power grid, district heating and cooling, data networks) [19,20]. This broad challenge includes a series of sub-challenges: (i) modeling the built environment to simulate the neighborhood energy dynamics [21][22][23][24], Energies 2021, 14, 3716 2 of 19 both for new constructions and for existing ones, (ii) planning an adequate monitoring and management, (iii) deploying the plan by integrating existing buildings with and energy management system (EMS), i.e., a platform allowing the visualization (dashboard) of monitored data, and some sort of control.…”

“…Energies 2021, 14, x FOR PEER REVIEW 2 of 20 challenges: (i) modeling the built environment to simulate the neighborhood energy dynamics [21][22][23][24], both for new constructions and for existing ones, (ii) planning an adequate monitoring and management, (iii) deploying the plan by integrating existing buildings with and energy management system (EMS), i.e., a platform allowing the visualization (dashboard) of monitored data, and some sort of control.…”

“…Figure 5. From the top: the five clusters of daily probability of occurrence for the appliances' and lights' electric energy use and the five clusters of daily probability of occurrence for the occupancy[23].…”