Norway is the largest producer of oil and gas in Europe.
Gas storage facilities are classified as critical infrastructure.
Such prices are recorded for the first time since the beginning of April.
Brussels says ‘full disruption’ would require contingencies including possible rationing.
The US has already banned oil imports from Russia, and European Union countries are aiming to do the same thing, gradually over the next year.
Ukraine is not a leader in the list of countries with the most expensive electricity.
Over the past week, world oil quotations have experienced serious volatility.