Airborne Wind Power Generation Employing Straight Bladed Wind Turbines

Hiroshi Okubo Kanagawa Institute of Technology

1030 Shimoogino Atsugi Kanagawa 243-0292 Japan okubo@me.kanagawa-it.ac.jp www.kait.jp/english/

Airborne Wind Power Generation Employing Straight Bladed Wind Turbines

Yasutake Takahashi4_{, Hiroki Endo}5_{, Kazuichi Seki}6 1_{Kanagawa Institute of Technology,}2_{TMIT; Tokyo Metropolitan University}

3_{Maeda Corporation,}4_{University of Fukui,}5_{Niihama National College of Technology,}6_{Tokai University}

A ground-generator-type airborne wind power genera-tion (AWPG) system is proposed for utilizing high and steady wind power over the canopy of a ground wind boundary layer The proposed system employs vertical-axis wind turbines carried by a kite or aircraft and a tether driving mechanism to convey the high sky wind energy generated by the windmill down to the ground generator. Research and development are currently in the stage of a Phase 1.5 prototype that includes two 0.65 m (span) x 0.6 m (diameter) straight bladed wind turbines The system is expected to produce wind energy power of 6 kW with an eight figured periodic flight, which represents approx-imately 30 times greater wind energy generation than the usual on ground operation of 0.2 kW.

Performance and power generation tests of the Phase 1.5 windmill model were conducted in October 2018 at the wind tunnel facility of Maeda Corporation. The wind tun-nel test showed that the power factor was 21% and the maximum power generation was approximately 20 W. We developed a field test model equipped with two Phase 1.5 wind turbines ( a single pair), and conducted a power gen-eration demonstration test of the floating wind turbine system by running a carry vehicle at Menuma Air Field on January 24-27, 2019. An outline of this test is provided in Figures 1-3. A generator was installed on the bed of the towing truck, and the number of revolutions of the gen-erator and the generated power were measured. The time history of the generated power and rotational speed of

the generator are indicated in Figure 4. A maximum of approximately 30 W of power generation was recorded.

Fig. 1 Overview of experimental setup

Fig. 2 AWPG field test

Fig.3 Generator (SKY-HR125) on vehicle bed

Fig. 4 Output power and rotational speed References:

[1] H. Fujii, H. Okubo, et al., High Sky Wind energy Generation on a Tethered System, Airborne Wind Energy Conference, Freiburg, Ger-many, October, 2017.

[2] H. A. Fujii, H. Okubo, et al., Tethered High Sky Wind Energy Gen-eration (HSWG) Progress Report in 2018, Proc. of the Grand Renew-able Energy 2018, Yokohama, Japan, 2018.