How Can System-Friendly Decentral Players Accelerate the Energy Transition? On the Example of Heat Pumps in the German Energy System

Abstract

The transition of energy systems towards renewable energy introduces significant intermittency, posing challenges to grid stability. One solution to this challenge is the integration of decentral players for the synchronizations tasks in the systems. This is often discussed as 'system friendly behaviour'. In this work, a framework is proposed for assessing the system friendliness of decentral players in relation to a reference system that incorporates both controllable and renewable energy generation, thereby expanding upon the work of Brucke et al. To achieve this, an energy system model is developed to determine controllable generation and storage operation based on fixed renewable generation and demand. A key feature of the model is its ability to display the competition between storage and controllable generation within the energy system. Using the power flows optimized by this model, two indicators for evaluating system friendliness in the shared generation of controllable and renewable energy are introduced: controllable capacity, which measures the impact on controllable generation infrastructure, and controllable energy, which determines the utilization of controllable energy. Using these indicators, case studies were conducted on different heat pump operational strategies. These strategies vary in their flexibility and the electricity prices they received within both current and future scenario-based German energy systems. The findings indicate that in energy systems with low installed renewable capacities, heat pump flexibility only increases system friendliness when optimized for energy efficiency. Likewise, the introduction of variable electricity prices did not increase system friendliness due to the limited availability of renewable energy for load shifting in lower renewable energy systems. In energy systems that are close to or already capable of meeting their demand solely with renewable energy, heat pumps utilizing their flexibility achieved reductions of up to 10\% in controllable capacity, relative to their maximum power demand, and reductions of up to 20\% in controllable energy, relative to their annual energy demand. Additionally, a larger spread in electricity prices further reduced controllable energy by up to 4\% of the annual energy demand of the heat pumps, highlighting that stronger financial incentives for a decentral player can increase system friendliness. The proposed framework provides a valuable tool for informed decision-making regarding the operational strategies and capacity planning of a decentral player, as well as for improving the evaluation of financial incentives.