Economy and sustainability analysis with a novel modular configurable multi-modal white-box building model

TL;DR

The paper presents a Modelica-based, modular white-box building model designed for seamless inclusion in district energy co-simulations. The architecture is split into three configurable parts: Building Envelope/Indoor Equipment, Occupancy, and Weather, enabling 36 scenario permutations that explore insulation levels, heating strategies, and occupancy patterns under different climates. Key contributions include a 5R1C envelope implementation, GSHP and gas-boiler models with buffering and PV+battery integration, occupancy-driven load modeling, and weather data interfacing, all framed for large-scale digital-twin co-simulation. Findings show heat pumps outperform gas boilers in well-insulated buildings, while poorly insulated buildings still favor gas boilers economically; overall, upgrading insulation combined with HP and PV/Battery yields the strongest sustainability and economic benefits, supporting district-energy digital twins and city-scale co-simulations.

Abstract

This paper presents a novel modeling approach for building performance simulation, characterized as a white-box model with a high degree of modularity and flexibility, enabling direct integration into complex large-scale energy system co-simulations. The introduced model is described in detail, with a focus on its modular structure, and proposes various configurations that include various building insulation, heating methods, occupancy patterns, and weather data to analyze different scenarios, and the energy consumption, CO2 emissions, and heating costs are compared and analyzed across 36 introduced scenarios. The thermodynamic behavior of the model is shown to be consistent with real-world conditions, and the comparison of the scenarios concludes that the use of heat pumps for indoor heating in well-insulated buildings has significant economic and sustainability benefits, whereas the use of natural gas-fueled boilers is more cost-effective for buildings with low energy ratings.

Figures (10)

• Figure 1: The modular building model in Dymola and its three parts.
• Figure 2: The building envelope model and its electrical 5R1C schematic diagram bruno2016.
• Figure 3: The appearance of the heat pump and radiator heating in the Modelica building model (left) and the schematic diagram of the ground source heat pump principle (right).
• Figure 4: The appearance of the gas boiler and radiator heating in the Modelica building model (left) and the schematic diagram of them (right).
• Figure 5: Signal flow graph of the relationship between battery, PV, household load and power grid. $P_{load}$ means the power consumption of load, $P_{PV}$ is the PV power generation, while $P_{feed}$ indicates the power fed into the power grid (positive means fed in, negative means drawn).