A high security of supply means that the energy sector can cover consumers’ demand for energy in the short and long terms with a high degree of security – including in the event of disturbances in production and crisis situations.

Supply must also be secured in situations with disturbances to operations in energy production and any crisis situations.

The security of supply is never 100%, but it is typically 99 point one or more percent.

Security of the power supply means the probability that electricity will be available when the consumer wants it.

Security of the power supply is a collective benefit: if one consumer loses his supply, the same thing will happen to many people, perhaps all consumers. Individual consumers (hospitals and certain companies) have, however, elected to invest in emergency power systems which can run if the supply from the official network fails. These consumers thus have a slightly higher security of supply than the average consumer.

So far, the Nordic countries have operated with two basic criteria for security of supply: there must be 20% extra capacity as a reserve relative to that time in the year when consumption is highest. The system must also be able at all times to cope with a breakdown at any one power plant or in any one transmission connection.

ETP Consult works on the “n-1” principle, that is, the power supply must be maintained even if the most important component fails, e.g. the biggest production unit or the most important transmission unit. This is a well-known principle which is traditionally used throughout the world when dimensioning the transmission network.

The quality of the electricity network depends on a large number of parameters which are precisely defined by international standards on the basis of which ETP Consult plans and advises.