The expected ramp-up of heat pumps and electromobility as part of the energy transition will result in an increasing overall load on the electricity grid. To take this into account for grid planning, grid operators typically use simultaneity factors or simultaneity functions to determine the expected peak load. In case of decentralized heat pumps, the electricity load correlates strongly with the thermal demand for heating and domestic hot water. Reduced efficiency at low temperatures affects the electricity load additionally, the operation of heating elements at low outside temperatures implies a further challenge for the grid. In addition to the peak load, the daily profile of the electricity consumption of heat pumps is of major relevance for electricity balancing management. Typically, electricity providers use temperature-dependent standard load profiles for electricity consumers. However, the number of active customers, who will adjust their consumption depending on electricity prices or the availability of (renewable) generation capacity and grid capacity, will significantly increase in the future. Hereby, flexible operation will affect both the maximum peak load and the distribution of electricity consumption over the days. To assess all these aspects, a comprehensive study has been performed using a large set of operational data derived from more than 6,000 installed heat pumps over up to 2.5 years as well as from scientific monitoring projects in Germany. To support the correlations derived from the operational data e.g. at very low temperatures, simulation models have been developed according to respective buildings, system designs and operational behaviours. To evaluate the impact of flexible heat pumps, the operation has been simulated and optimized with respect to flexible tariffs for future heat pumps, considering electro-mobility as well as renewable energy market penetration.
Krause et al. (Mon,) studied this question.