THE SOLUTION

What if the intrinsic shape of the blade could change? Perhaps in the same way that a bird’s wing changes shape during different flight scenarios, giving lift when needed but then morphing in shape to dial back the forces as the wind gets stronger.

South African start-up Brayfoil Technologies has patented a method of changing the shape of a wing in operation, while linking that shape change to the pitch of the wing. A technological breakthrough sought after by some of the world’s largest innovation and aerospace agencies, but never quite perfected to the point of being viable, Brayfoil’s intellectual property offers a groundbreaking new way of thinking about how wings operate, which replaces complex shape-change systems (such as flaps and ailerons on aircraft wings) with a simple shape-changing shell.

Coupled with a unique approach to pitch angle, with pitch being driven by the physical forces created by the shape, this makes the blade’s shape adapt faster to changing winds, much in the same way a bird’s wing changes both the angle and the shape of its wing as it comes in to land.

What this translates to in a windturbine application is a reduction in the twist and camber in the blades, an astonishing reduction in storm loadings of up to 90 per cent, a decrease in operational loads of up to 24 per cent, and an increase in performance of up to 60 per cent during unstable wind scenarios.

The net effect here is lower forces on the entire structure, which can be used in a number of ways. Wind turbines can either be made more reliable, or the blades can be made longer. For the same structural strength at the base, the introduction of this tech is projected to allow a 13 per cent increase in blade length, which relates to a significant 25 per cent annual energy production increase. Technology such as this would change the economics of wind power even further, resulting in a 20 per cent decrease in the lifetime cost of energy, particularly valuable in offshore floating wind-turbine applications which are currently in need of enabling technologies in order to bring costs down.

Another important aspect of this is the advances in recyclability. Recyclable resins and composites are becoming the industry standard, and these are advances with which Brayfoil’s technology is well aligned, while not changing the manufacturing process significantly. With cost estimates suggesting that the tech could be capex and opex neutral, this will be a major focus of future development.

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