18 May 2017

O.2.3.2 Flexibility of heat pump pools: The use of SG-Ready from an aggregator’s perspective

In this work the response of a heat pump pool towards direct load control signals sent by an aggregator is analysed and a characteristic response is presented. The signals differ by type, duration and frequency. The used signals are based on the SG-Ready definition. It is essential to understand the reaction of heat pump pools towards direct load control signals in order to use their flexibility. A simulation experiment is used to identify the response of a heat pump pool towards single and repeated SG-ready signals of different duration sent by an aggregator. The used pool consists of 284 heat pump systems connected to thermal energy storages each. Building type and size, as well as heat pump system sizing are chosen to reflect conditions representative for Germany and randomised to reflect diversity of buildings, sizing and control parameters.
It is shown that most energy can be shifted for repeated signals applied for a duration between 15 minutes to 60 minutes. In this case losses reach up to 17% of the invested energy. The use of the back-up heater increases flexibility significantly but can lead to losses up to 70% of the invested energy, especially for long signal durations. It should be highlighted that the different SG-ready options lead to different shifting potential and different efficiencies. Furthermore the influence of season on heat pump flexibility is studied.