Storage influence in a combined biomass and power-to-heat district heating production plant

Abstract The increasing penetration of wind and solar electricity becomes challenging for grid operators. Interconnecting electrical and thermal networks through the Power-to-Heat concept brings flexibility to the electrical grid while supplying a significant renewable source to District Heating (DH). In the present paper, we study a DH production plant composed of a biomass generator, a heat-pump and a heat storage in the French energetic context. We assess the techno-economic performances of this system using Mixed Integer Linear Programming (MILP). A multi-objective parametric optimization method is applied to size the system using the available quantity of biomass, the maximum CO 2 content and minimum renewable energy ratio (REnR) of the heat production as e-constraints. Our analysis shows that without strong constraints, heat pump and daily storage are used. For a limited amount of biomass available, we also show that investing in an inter-seasonal storage is necessary to reach high REnR. For comparisons, this energy system is also assessed with the Danish and German electric mix. We then verify the sizing stage results on the operational performances of a non-linear numerical simulator. With that methodology, it is possible to evaluate the impact of the MILP modelling level of detail on the obtained results. An error of 5.1% on the production trajectories is here obtained for a given system.