SIMEC Atlantis makes progress on novel variable pitch system for 2MW tidal turbines

SIMEC Atlantis Energy is preparing to start with the assembly and testing phase of its novel variable pitch system for tidal energy turbines, developed as part of a collaborative EU-backed project.

The Edinburgh-based tidal energy company said it is reaching the end of the manufacturing period for the novel pitch system developed in the ‘VPS for Tidal Turbine Generators (VPSTTG)’ project, which received €1 million in 2018 from the European Union.

The project, run in collaboration with Spanish manufacturing partner Asturfeito, aims to develop a novel variable pitch system (VPS) for tidal turbines at an affordable cost.

Said to be one of the critical components of a tidal energy turbines, the VPS alters the angle of the blades relative to the flow, and is used to control the output of the turbine, as well as providing soft startup and braking.

“We completed the design of the pitch system in 2020, and together with our project partner Asturfeito, we are now reaching the end of the manufacturing period, and will shortly be entering the assembly and testing phase”, SIMEC Atlantis said in an update.

The company has conducted the factory acceptance testing of the actuator mechanism, a vital sub-system that connects the motors to the blades and allows the blade pitching action to take place.

The gearbox, housing the actuator mechanism, was designed by the UK-based company Involution, and built at DePe Gears facilities, which also served for testing the equipment.

“At Involution we specialise in bespoke high-power density epicycle gearboxes that are ideally suited to this application where an actuator must be fitted inside a small enclosed space.

“We have worked closely with SIMEC Atlantis on previous main gearbox designs and we are pleased to be involved on this 2MW pitch system. This gearbox has to react with the large torsional loads on the blades caused by the tidal flow.

“We have now completed the manufacture at DePE Gear, and we will thoroughly load test the gearbox both in UK and Spain to confirm its attributes and reliability”, Involution said.

A second stage of full load testing will be carried out at Asturfeito’s site, following full assembly of the system.

There, the partners will apply not only torsional blade loads, but the full 50-ton thrust loads expected to be encountered in real operational environment service.

“This has been technically challenging to achieve, and the first time SIMEC Atlantis has attempted this in onshore testing, but the performance and reliability are paramount for this subsea system”, SIMEC Atlantis said.

The novel VPS will be used on future SIMEC Atlantis turbines, supporting the development of the tidal industry and the European supply chain for this market.

The company’s next generation turbines, including the 2MW AR2000, are moving to a subsea architecture where multiple turbines are connected to a single subsea cable, running at the same speed, which makes the VPS even more important for controlling the power, according to SIMEC Atlantis.

The AR2000 tidal turbines are expected to be deployed on future phases of SIMEC Atlantis’ iconic MeyGen project in Scotland, the wider company project pipeline and will also be available for sale to commercial developers.

As reported earlier, adding only two of AR2000 turbines to the MeyGen project could increase its yield for 40%.

The innovations are also expected to significantly reduce MeyGen project’s infrastructure costs by removing the requirement for a dedicated export cable per turbine and should also result in reduced vessel installation costs, according to the company.