An Ultra-Thin 4.3 mm Generator for Energy Harvesting on Operating Wind Turbine Blades

Wind energy is a crucial technology for the shift from a world driven by fossil fuels to one driven by renewable energies. Wind turbine operators thus seek reduced maintenance costs and improved efficiency. In this direction, non-intrusive wireless sensor networks have been proposed to address the continuous monitoring of wind turbines. A wireless sensor node must operate for long periods, ideally perpetually. Previous works have focused mainly on photovoltaic and motion-based energy harvesting to provide a stable and reliable energy source. This work proposes an ultra-thin 4.3 mm surface wind-induced rotation electric generator as energy harvesting technology, enabling a self-sustaining wireless sensor node for wind turbine blade monitoring. In addition to theoretical considerations, three prototypes are realized and characterized, comparing different rotor sizes and magnets with an operative wind speed dynamic range between 10 and 80 ms
⁻¹
, The experimental validation demonstrates the capability of the proposed wind-based har-vester to reliably and continuously supply surface sensor nodes, reaching up to 750 m
$W$
at 70 ms
⁻¹
with a power density of 5.6 m Wcm
⁻¹
, 27 times higher compared to a photovoltaic energy harvester deployed with equal operative conditions on a 10 MW turbine at 207
$\mu\mathrm{W}\text{cm}^{-2}$
. Our solution does not need a large power buffer, e.g., rechargeable batteries, delivering constant energy even during adverse weather conditions and nighttime.