Summary: | Increased use of variable energy and integration of electricity markets in the European Union have led to new challenges when balancing supply and demand in the grid. Load management is a possible way to manage these challenges by adjusting electricity consumption in order to balance the power system. Household appliances can be used for this purpose, for example by providing automatic frequency control. The aim of this master thesis is to investigate the potential of load management from private households and to examine how the power system is affected by a more flexible electricity consumption. The thesis focuses on fridges as automatic frequency control reserves and the ability of fridges to balance the power system. Attributes such as capacity, activation time, persistence and the effect of load reconnection has been modelled in Simulink, Matlab. Complementary interviews with actors from the electricity industry have been done to summarize their insights on demand response. The results indicate that fridges can be used as a part of the automatic frequency controlled reserve FCR-N, based on assumptions made in this study. However, current requirements imposed on balancing resources are not fully met by the fridges. In order for household appliances to provide the needed flexibility, some requirements might need to be rephrased. The results also show that the capacity for providing balancing services differs for positive and negative imbalances, as consumption can be reduced with 30 MW and increased with 66 MW. When controlling the fridges by moving the reference temperature, there is a risk that the appliances will synchronize with each other, i.e. reconnect or disconnect at the same time, resulting in frequency oscillations. It is therefore important that load management is designed to avoid this kind of behavior.
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