Phase one of the UK’s Meygen tidal stream power project is expected to enter its 25-year operational phase within weeks according to its developer, Atlantis Resources.

Commissioning has begun on the 6 MW first phase of the project in Scotland’s Pentland Firth after reinstallation of the fourth 1.5 MW turbine in mid-October. The project’s three Andritz Hydro Hammerfest turbines and one Atlantis turbine were uninstalled earlier this year in order to add system upgrades.  

All four turbines have now been reconnected to the grid, Atlantis said, with final completion testing the next step and the formal end of construction works expected imminently.

According to Atlantis, the installation’s total production has now surpassed 2.6 GWh, with over 800 MWh dispatched to the grid in September. On completion, the array’s first phase is expected to power 2600 households.

The project is planned to reach 86 MW once fully completed. Phase 1B will involve the installation of another four 1.5 MW turbines, while in phase 1C Atlantis aims to add 49 73.5 MW turbines at an estimated cost of £420m ($557m), with installation planned to begin in 2019.

The turbines sit on individual foundations weighing between 250 and 350 tonnes, coupled with six ballast blocks weighing 1200 tonnes that provide horizontal stability. Each turbine has a dedicated subsea array cable which feeds into an onshore power conversion unit at the Ness of Quoys, where the low voltage supply is converted to 33 kV for export via the 14.9 MW grid connection into the local distribution network.

Tim Cornelius, Atlantis Resources CEO, said his firm had “asked the government to enter into a bilateral negotiation for 80 MW of capacity to allow us to proceed with the construction of Phase 1C of the MeyGen project without further delay”.

“Tidal stream power costs are reducing all the time with a strong trajectory towards achieving parity with established renewables such as offshore wind,” he added.