The 300km subsea direct-current electricity connection to connect the two countries' power grids is expected to be completed in early 2019.
Cobra - COpenhagen BRussels Amsterdam - will run from Eemshaven in the northern Netherlands to Endrup in eastern Denmark.
The European Commission is supporting the project with a €86.5m ($112m) grant under the European Energy Programme for Recovery (EEPR).
"The cable will make a significant contribution to the realisation of a sustainable international energy landscape," says Mel Kroon, chief executive of Dutch TSO TenneT.
Peder
