Economic affairs minister Henk Kamp is looking at ways to encourage gas companies like NAM to extract more gas from under the North Sea to reduce Dutch dependence on Russia, broadcaster Nos says on Wednesday.

Kamp is on Wednesday visiting a number of offshore wind farms which, the government hopes, will provide enough electricity for five million households within eight years. But the minister is also keen to use the North Sea for other sources of energy, the broadcaster says.

Research institute TNO and the ministry say almost 120 billion cubic metres of gas is under the North Sea in 268 known locations. In addition, up to 165 billion cubic metres is waiting to be discovered, Nos says.

Kamp has been forced to cut back on gas extraction from fields under Groningen province because of the risk of earthquakes. Tens of thousands of homes need to be reinforced because of the impact of ground settling once the gas has been removed.

The Netherlands operates several gas fields off the Dutch coast. Since 2010, companies have been able to claim a 25% subsidy on their investment and Kamp is to look into whether this is sufficient, the broadcaster says.