Background

Interest in alternative energy sources has increased over time as pollution awareness and resource scarcity makes fossil fuel based energy less attractive. One such alternative energy source that is gaining increased attention is energy harvesting from ocean and wind currents.

Rigid wing energy harvesting kites are used to extract energy from such currents. These kites frequently adjust operating altitude/depth to follow the movement of currents to maximize energy generation. However, when adjusting altitude/depth, the wing geometry that maximizes power generation shifts. Unfortunately, current kite designs do not adjust their wing geometry in any way, thus missing out on a potential increase in energy production.

A rigid wing energy harvesting kite that could actively adjust its wing geometry to maximize energy production would result in a large efficiency gain and thus would be highly desirable.

Technology Overview

NC State researchers have developed a tethered energy-harvesting kite that dynamically adjusts its shape in response to changing altitudes, thus maximizing the energy harvesting potential of the kite. In particular, at low altitudes, a smaller wing is more optimal, while at higher altitudes, a larger, more lifting wing design is optimal. This innovation adjust to achieve such optimization, and works for both air and water harvesting kites.

This active wing adjustment in response to altitude can increase net energy production by 15% as compared to the currently commercially available, altitude/depth adjusting kites. shows the improvement. This technology’s performance is shown in the blue line.

Further Details

Predictive Control of a Morphing Energy-Harvesting Kite, 2022. https://ieeexplore.ieee.org/abstract/document/9966031?casa_token=Wv_Gtf3j2P0AAAAA:ethSmwGgiY_Ktwdy8NVXugQJ-FbGa4aYV78–P7Je2LcIIHYYSwEiN_7GhwVnhIvykUyUrzGxw

Benefits

Improved energy harvesting efficiency;
Reduced reliance on fossil fuels.

Applications

Energy harvesting from high altitude wing currents;
Energy harvesting from ocean currents;
Renewable energy sources.

Opportunity

This innovation has been fully validated in simulations. NCSU is now searching an industry partner to begin largescale production of these active wing morphing kites.

Improved Efficiency Energy Harvesting Kite via Active Wing Morphing

Seeking