A new ocean current energy system has been successfully deployed, according to the company behind it.
The Subsea Power Hub (SPH) is being tested by Aberdeen based EC-OG at Shapinsay Sound, Orkney.
The company said the system is "performing in line with technical predictions".
The unit will be left to operate autonomously over the summer months while it is checked using wireless data monitoring.
EC-OG said the SPH is a ground-breaking hybrid drive system which uses a marine energy convertor to produce energy which is stored in a lithium-based unit.
Engineering director Robert Cowman said: "Although the weather was not on our side, we were still able to successfully complete the installation and commence testing ahead of schedule.
"The system is performing very well and I'm pleased at how quickly the results are correlating with the theoretical basis for the test. Having a vertical axis turbine, means that the SPH is operating effectively in these unpredictable, sporadic flow conditions.
"Thanks go to the EC-OG team as well as those who have helped us at EMEC, Leask Marine, Castle View and Scottish Enterprise."