The modern society, including emergency preparedness, is becoming increasingly dependent on electricity. For individuals, electricity has shaped living patterns that are difficult to abandon. For automated and digital systems, even short power cuts affect societal functions and people's everyday lives, at workplaces as well as in private homes. Over the past twenty years, there have been several major power blackouts, internationally as well as in Sweden, accentuating how vulnerable many vital sectors in society are. Power outages have several causes, e.g. extreme weather events and human-triggered events such as malfunctions or malicious acts, including cyber-attacks. These outages often lead to huge costs for the society, including business, as well as causing human suffering. Disruptions in energy supply can also have direct or indirect impacts on the health of the civilian population. However, the relationships between power outages and health appear to be rather unexplored. There is thus a need to increase the understanding of how power outages, regardless of cause, directly or indirectly can cause health impacts. The aim of this study has been to study short as well as longer power outages, and their direct and indirect consequences for the society and public health. Some general conclusions were that the cases studied in principle are consistent with previous general estimates of consequences from power outages. Shorter outages with a few exceptions lead to limited impact. However, the costs for society can be significant even for short outages. Patients cared for in their homes with electrical medical equipment are particularly vulnerable to power outages. Fatalities occur, but often the mortality is not primarily caused by the outage but from e.g. fall injuries or carbon monoxide poisoning. Long interruptions are challenging for the food supply and cause significant stress and mental health impact. Season, weather, time of day and the length of the power outage are very important for its consequences. Good planning, including sufficiently sized, maintained reserve power, with sufficient fuel, limits the negative impact on society.