Sweden has started burning oil for its electricity production. Despite the emergency measure, Sweden exports more electricity than we import.
When it is cold and windless throughout the Nordic region, there may be a shortage of electricity. The electricity grid needs to have as much electricity consumption as electricity production, all the time.
The problem when it is cold and windless is that wind power does not supply electricity at the same time as many electricity consumers have great needs for electricity.
If Sweden’s electricity imports are then not enough, the power reserve must be started. Then the oil-fired Karlshamnsverket is started.
– At 07.15 this morning, the decision was made that they start Karlshamnsverket at the lowest production, in order to be able to quickly increase the effect if necessary, says Erik Böhlmark at Svenska kraftnät.
Karlshamn’s oilworks produces at the lowest level, 60 megawatts. At most, Karlshamnsverket can contribute 562 MW to the power reserve according to the agreement with Svenska kraftnät.
The free electricity market
The crux is that Sweden must not stop the export of electricity, not even when our own electricity network is short of power. This is a violation of EU law.
In the free market, Sweden exports electricity, at the same time as we import electricity from Denmark, Germany, Norway and Lithuania, among others. The electricity from Norway comes from hydropower to a large extent, but in Germany and Lithuania more than half of the electricity is produced by coal power plants and gas plants.
– Net, we export. The type of electricity we import varies from hour to hour. Some hours it is predominantly wind and solar power, other hours it is predominantly fossil-based power from gas and coal, says Erik Böhlmark at Svenska kraftnät.
If electricity is cheaper to produce in Sweden than another country, we export, and vice versa.
– It is a prerequisite for being able to switch to renewable electricity production. When you expand weather-dependent production sources, sun and wind, you need to be able to both import and export, says Erik Bölhmark.
The frequency of the electricity grid
In every second, electricity production and electricity use must match in the electricity system. The frequency is used as a measure of matching. In the Nordic electricity system, the frequency must be 50 Hz.
In the event of disturbances, when the frequency falls or rises too much, measures must be taken so that the system regains its balance. Electricity production can be increased or decreased.