Norwegian industrial giant Hydro and compatriot next-generation offshore wind technology developer World Wide Wind (WWW) plan to explore using recycled aluminium to build a potentially revolutionary new floating design, under a letter of intent (LoI) signed today (Thursday).
The pair – which expects to expand its collabloration to investigate employing the lightweight metal alloy in the “renewable wind industry” more widely – will lead-off with construction of a prototype of WWW’s contra-rotating vertical turbine (CVRT) concept, which features two omnidirectional rotors spaced apart on a tower-spar structure all anchored with a novel turret-shaped mooring system to the seafloor.
The CRVT – as Recharge reported exclusively when the design was launched last August – could be a game-changer for the sector, deflecting away “destructive levels of torque and vibration” and slashing floating wind’s levellised cost of energy (LCOE) to €50/MWh ($49.85) from current levels over 2.5-times higher.
WWW calculates an aluminium-based CRVT would be “between 10-50% percent [lighter than] a semi-submersible steel [floating turbine] depending on whether one accounts for fluid ballast or not”.
“Today, wind turbines used for floating wind have more or less the same design as turbines meant for land-based wind. In effect we are moving a land-based technology offshore,” said Trond Lutdal, WWW’s CEO.
“We [at WWW] are developing a new type of floating wind turbine for deep waters, with significant benefits relative to current technology in terms of energy production, cost, scalability, and environmental footprint [by using] aluminium components in parts of the wind turbine structure.”
Lutdal added: “Having Hydro as a partner in developing our turbine using sustainable materials as aluminium, is a big step forward for us. Use of local content will be part of our common strategy going forward.”
Trond Furu, research manager at Norsk Hydro Corporate Technology research manager Trond Furu said: “For Hydro this is an entry into the wind turbine production chain and at the same time we are strengthening our position within renewable energy,
“Hydro sees the potential for increased aluminium in many industries, includkng wind power.”
Under the LoI, Hydro, which is one of the largest aluminium producers in the world with over 50 smelting facilities in operation, and WWW aim to now form “a collaboration team, which will plan and detail relevant activities and actions”.
The slender-profiled CRVT, which tilts in the water with the wind, “part vertical and horizontal axis”, is engineered to minimise the wake effect – the turbulence created as wind moves through a rotor-star – created by three-bladed turbines, meaning a developer could “halve the distance between turbines on a wind farm, which is super-important for efficiency in capturing wind in a project site area”, said Lutdal speaking with Recharge last year.
Moving forward, WWW aims to accelerate development of the technology with “rapid prototyping” to get up to a 3MW model by 2026 of the CRVT and then make the leap to the giant 40MW design by 2029, with an eye on “spin-off applications” for the concept including offshore charging stations, renewables-powered aquaculture and green hydrogen generation.
