The EUR1.2m ($1.6m) plant was developed by Scottish company Voith Hydro Wavegen and has been handed over to Basque energy firm Ente Vasco de la Energía.
The 300 kW facility comprises 16 turbines housed within a breakwater at the port of Mutriku. It has been designed for a 25 year operational life and will provide electricity for 250 homes via national grid.
Matthew Seed, chief executive of Inverness-based Voith Hydro Wavegen, said: “This is very exciting news, not just for our company, but for the whole marine energy sector. This major milestone is a demonstration of just how far the industry has developed in recent years.”
In 2000, Voith Hydro Wavegen developed the first commercial-scale, grid-connected wave energy plant on the Scottish island of Islay, and the facility continues to operate as a demonstration project.