In the first part of a new climate plan, Denmark has proposed two 2GW "energy islands" by 2030.
The first will be located in the North Sea, with an initial 2GW of capacity but space to expand to 10GW.
The second will turn the island of Bornholm in the Baltic Sea into an energy hub, again collecting 2GW of offshore wind energy production.
Denmark's finance ministry said the use of the islands would mean a more efficient use of resources and fewer onshore electricity masts.
This 4GW of new capacity more than doubles Denmark's current operating fleet and will be more than the population requires, so the finance ministry said exporting the power will be necessary. Bornholm is already connected to the Swedish grid.
The additional power will also be converted using Power-to-X technology to help decarbonise sectors such as aviation and heavy transport, the ministry said.
"By establishing the world's first two energy islands, we embark on a whole new era in the Danish wind adventure," said Danish climate minister Dan Jørgensen.
"We will be able to use the green power in the tanks of trucks, cargo ships, and aircraft.
"We present a package that delivers both CO2 reductions in the short term and paves the way for a climate-neutral future in Denmark," Jørgensen added.