Energy generation company SIMEC Atlantis Energy (SAE) has completed the design for a new 2MW tidal power turbine system – the AR2000 – incorporating the world’s largest single-rotor tidal turbine.

The single-axis turbine will be capable of powering rotor diameters of 20m-24m and will operate a cut-in speed of less than one metre per second.

Taking more than two years to develop, the AR2000 has improved on the AR1500, which was deployed and operated under the MeyGen tidal energy project in the Pentland Firth, offshore Scotland.

SAE has invested more than £5m in the largest single-rotor tidal turbine, which is expected to be deployed during future phases of MeyGen.

New features include an electro-mechanical pitch system, 360-degree vertical rotation, upgraded on-board health monitoring and diagnostics systems, and optimised critical system redundancy.

According to the designers, the AR2000 will have a lifespan of 25 years, with routine maintenance every six years.

SAE director of Turbine and Engineering Services Drew Blaxland talks about the new AR2000 design, and what SAE hopes to achieve.

Talal Husseini: Tell us more about SAE and the new AR2000 turbine design.

Drew Blaxland: SAE is a global sustainable energy generation company involved in the design, development, construction, and operation of power projects around the world. Our heritage is in tidal power generation. The SAE Turbine and Engineering Services division designs, supplies and maintains world-leading tidal turbine systems, including subsea connection equipment.

Its new AR2000 system builds on the experience of the AR1500 and Seagen. It represents the culmination of our development experience; a commercially scalable system that allows many machines to be linked and operated in parallel.

How has the design improved on the previous AR1500 model?

It’s bigger, with a larger rotor (20m diameter instead of 18m) and higher rated power (2MW instead of 1.5MW). The largest capacity single axis system on the market. This increase is not achieved at the expense of making the turbine longer or heavier.

We are keeping roughly the same frame size as the AR1500 but using the understanding we have gained in operating the AR1500 to make the control system smarter, the structure more simple, and less onshore power conversion balance of plant. A number of turbine components are also improved, most notably the rotor pitching system. This all has a dramatic effect on lowering the systems cost of energy production.

How will the new turbine benefit future phases of the MeyGen project?

Higher energy output, for greater income at lower capital outlay. At volume in sizeable arrays, as proposed in future phases of MeyGen, this allows them to compete at a power price comparable to offshore wind.

Do you expect the AR2000 to inspire larger tidal development projects?

Yes. We are now positioned to supply power projects with complete systems, from the turbines and foundations right up to the grid connection, including marine installation. The AR2000 will allow multiple turbines to be connected on a single export cable, using a simple subsea hub to split the connections to each turbine.

In the past, tidal turbines have either needed one cable to shore per turbine, or less-than-fully-reliable power electronics housed in the turbine or in a subsea hub. The AR2000 is designed for large arrays, keeping down the cost of subsea infrastructure.