Grid-connected tidal test site
Our grid-connected tidal test site at the Fall of Warness is situated just west of the island of Eday - lying in a narrow channel between the Westray Firth and Stronsay Firth. The site was chosen for its high velocity marine currents which reach almost 4m/sec (7.8 knots) at spring tides. As tides flow from the North Atlantic Ocean to the North Sea, they quicken as they are funneled through Orkney's northern islands.
Current meters characterise the tidal and wave conditions on site, and a purpose-built weather station is situated onshore providing real-time met data for the site. This data is fed into a sophisticated SCADA (supervisory, control and data acquisition) system.
EMEC offers seven cabled tidal test berths at depths ranging from 12 m to 50 m in an area 2 km across and approximately 4 km in length.
The 11 kV subsea cables feed into EMEC's substation at Caldale in Eday which houses the main switchgear, backup generator and communications room. The substation controls the supply from each tidal device and connection to the national grid. An adjacent laydown area offers developers the opportunity to use conditioning equipment for converting electricity from the level at which it is generated to grid compliant electricity. Another building on site holds the Scottish and Southern Energy transformer where the 11 kV is transformed to 33 kV. Eday is linked to both Westray and Sanday by subsea cables that form a ring through the Northern Isles and feed into the national grid.
In addition to transporting electricity, the cables contain fibre-optics which allow developers to communicate with the devices and transmit monitoring data back to our data centre and office facilities.
The test site has 7.2 MW export capacity and is being expanded further to meet industry demand and support the testing of multiple longer-term array demonstrations on site.
For details of the tidal energy demonstration projects that have taken place at the site, visit: our tidal energy clients.
To further increase generation capacity in the near term, EMEC has been exploring alternative offtake opportunities for ocean energy. This has seen us develop our onshore facilities at the tidal test site into a renewables integration R&D site to demonstrate complementary energy vectors. We currently have a hydrogen electrolyser and vanadium batteries installed which have been used in demonstration projects exploring the production of 'green hydrogen' from the tidal energy generated at the test site. In 2017 EMEC produced the world's first tidal generated hydrogen; in 2025 another world first was achieved with the demonstration of a 3-in-1 system combining tidal power, battery storage and hydrogen production.
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