Assessing community-scale energy supply scenarios using TRNSYS simulations

Small-scale district heating and cooling systems represent an interesting way to value low-grade waste heat from local industries and to increase the use of renewable energy for building heating and cooling purposes. However, the many available energy sources (biomass, solar thermal, geothermal, biogas, urban waste, etc.) and the different ways of using them (CHP, direct burning, gasification) result in numerous design options. Optimizing these hybrid systems requires considering operating strategies concurrently to system configuration and component sizing, and this process must take into account the constraints and opportunities of each individual project. This paper presents the simulation of different energy supply scenarios for a community-scale district heating scheme in a real-life development project covering 1500 housing units and 4000 square meters of integrated commercial buildings. The simulations take into account the development schedule of the project over a span of 20 years. The paper shows how the use of TRNSYS helped the integrated design team select energy sources and distribution strategies, and how to balance long term programmatic resilience with maximum energy efficiency.