The world's most powerful wind turbine has been successfully installed in waters off the coats of Aberdeen, developers said.
Vattenfall confirmed the first of 11 turbines in its European Offshore Wind Deployment Centre (EOWDC) had been put in place.
Project director Adam Ezzamel said the giant device is so powerful that one single rotation of its blades could provide enough electricity to power an average UK home for a day.
The turbines are each 191 metres tall, with each blade being eight metres long, while the 164-metre rotor has a circumference larger than that of the London Eye.
The Aberdeen Bay development, which will be Scotland's largest offshore wind test and demonstration facility and will trial next generation technology, has been hit by delays - including legal challenges from Donald Trump who claimed the turbines would ruin the views from his golf course at Balmedie.
But the installation of the initial turbine comes two weeks after a giant floating crane successfully installed the first of the foundations, with these using a new style never employed before in a commercial project.
The turbine's installation marks the first time a 8.8 MegaWatt model has been deployed commercially in the offshore wind industry.
The development will have two of these, together with nine 8.4 MegaWatt turbines, with the developers saying it will be able to produce the equivalent of more than 70% of Aberdeen's domestic energy needs.
Mr Ezzamel said: "The first turbine installation is a significant achievement and credit to the diligence and engineering know-how of the project team and contractors.
"For it to be one of the 8.8MW models makes it an even more momentous moment because it further endorses the EOWDC as a world-class hub of offshore wind innovation.
"We are very excited by the cutting-edge technology deployed on all the turbines and it is remarkable that just one rotation of the blades can power the average UK home for a day."
Jean Morrison, chair of the Aberdeen Renewable Energy Group (AREG), said: "The EOWDC is leading the way in terms of innovation for the offshore wind sector and will help enable the next generation of offshore wind.
"It's a real coup for the region to have the world's most powerful turbines on its doorstep and cements Aberdeen's position as a major global energy city. It also will lead us to a greener future."
Stephanie Conesa, policy manager at Scottish Renewables, said: "Scotland is home to approximately 25% of Europe's offshore wind resource and projects like Vattenfall's European Offshore Wind Deployment Centre in Aberdeen promise to harness this potential on a massive scale.
"This ground-breaking facility leads Aberdeen's ongoing transition from fossil fuels to renewables, and reinforces Scotland's global energy status.
"As the windiest country in Europe with some of the deepest waters, we should be proud of Scotland's burgeoning offshore wind industry.
"With many more promising offshore wind sites on our doorstep, we hope to see similar facilities deployed in Scottish waters in future so we can fully utilise our country's natural resources."