If the demand of power is greater than the supply there is risk for a lack of electricity.
One such example is if there are problems with the power production during cold winters, since large amounts of electricity are needed for heating houses and companies.
If there is a lack of electricity there is a risk for major problems with the power supply in all of or parts of Sweden. To avoid this Svenska Kraftnät (the Swedish National Grid) has the authority to order the switch off parts of the electrical grid. This is a way of directing the electricity to the parts of society where it is most needed. The prioritised users are those that on a local and regional level ensure that society works, for example hospitals, homes for the elderly, emergency services, water supply and telecommunications. As a result of this, you as a customer can be out of electricity while your closest neighbour still has power. In that case it may be that your neighbour’s house happens to be connected to a prioritized part of the grid that is also connected to users important to society.