Tidal power generation company Atlantis Resources has connected its MeyGen project in northern Scotland to the 33kV Ness of Quoys distribution network.
The project has been connected after the network's operator Scottish Hydro Electric Power Distribution (SHEPD) installed one of the longest underground export cables in the UK.
Atlantis Resources' CEO Tim Cornelius said: "The connection of our flagship MeyGen project to the SHEPD distribution network marks a huge technical major milestone for Atlantis and the tidal stream industry more broadly.
"It has involved years of hard work, persistence, perseverance, and determination by our team and all of the contractors and consultants involved in the onshore work. We believe this is now the world's largest energised grid connection of any commercial tidal stream array.
"We have made great progress over recent months on turbine and foundation preparation and we very much look forward to delivering first power to the grid later this year. This will be a huge event for our company and the global marine power industry."
After completion, the 400MW project is expected to generate emissions-free electricity, sufficient to power 175,000 households in Scotland.
The first tidal turbines are expected to be deployed over the coming months, with first power expected in the second half of this year.