Control strategy design for large-scale heat pumps: An economic-oriented analysis
Heat pumps are a central, well-established technology to decarbonize the energy system. Coupled with intelligent control strategies and thermal storage, they can align heat demand with renewable energy generation through load shifting, thereby enhancing both system flexibility and grid stability. This study investigates the impact of different rule-based control strategies for large-scale heat pumps in residential buildings, focusing on their response to fluctuating renewable energy production, variable electricity prices, and grid signals. Simulations of a representative multi-family house model with a centralized 60 kW heat pump are conducted across four control scenarios. The building’s thermal mass is modelled as thermal storage and preheated to shift electricity consumption out of periods of high electricity prices. The overarching objective is to reduce operational costs for the user. To achieve this, a simple “Base-case” Scenario (A), including possibility to consume and sell self-produced PV electricity, is compared with three alternative strategies: Scenario (B) “Photovoltaic-induced overconsumption”, where economic profitability arises by increased consumption of PV self-produced electricity; Scenario (C) “Variable electricity price”, where the heat pump load is positively shifted in response to negative electricity prices; Scenario (D) “Interruptible tariffs”, where profit margins are a direct consequence of incentivized reductions in grid tariffs. Results indicate that Scenario (D) achieves the most significant operational cost savings (10.7% OPEX reduction compared to base-case), driven by the reduced grid fees, while maintaining thermal comfort >99.7% of the times. However, the economic benefit comes at the expense of the system performance, with a COP reduction of 6.9% compared to the base-case.