Self-Regulating Wind Speed Adaptive Mode Switching for Efficient Wind Energy Harvesting Towards Self-Powered Wireless Sensing.

Small-scale wind energy harvesting, which can replace batteries to power small electronic devices and realize self-powered systems, has been extensively studied. To improve the working wind-speed range and output power of small-scale wind energy generation systems, we propose a synergetic hybrid piezoelectric and triboelectric mechanism for galloping wind energy harvesting. In this mechanism, a piezoelectric energy harvester (PEH) works in the vibration area and starts working at low wind speeds, while triboelectric nanogenerators work at the vibration boundaries and cooperate with the PEH at high wind speeds. The triboelectric nanogenerator boundaries can (1) constrain the maximum deformation of the beam at high wind speeds to avoid damage to the PEH, (2) increase the vibration frequency to enhance the electromechanical conversion efficiency, and (3) allow the PEH to have a low equivalent stiffness to work effectively at low wind speeds. A dynamic model is presented to characterize the synergetic hybrid piezoelectric–triboelectric wind energy harvester (SHPTWEH) and this is verified by experiments. The results show that the triboelectric nanogenerator boundaries greatly expand the effective working wind-speed range, and the total average power output by the prototype SHPTWEH was 0.24 mW at a wind speed of 14 m/s, which was 2.3 times that of the PEH alone.

Soft-Soft Contact TENG Using Nonlinear Coupling Galloping Phenomenon for Harvesting Wind Energy

Wind energy holds potential for in-situ powering large-scale distributed wireless sensor nodes (WSNs) in the Internet of Things (IoT) era. To achieve high performance in wind energy harvesting, a coaxial counter-rotating triboelectric nanogenerator with lift–drag hybrid blades, termed CCR-TENG, has been proposed. The CCR-TENG, which can work in non-contact and soft-contact modes, realizes low-speed wind energy harvesting through a combination of counter-clockwise rotating lift-type blades and clockwise rotating drag-type blades. Non-contact CCR-TENG realizes low-speed wind energy harvesting at wind speeds as low as 1 m/s. The output of a CCR-TENG, working in soft-contact mode, achieves 41% promotion with a maximum short-circuit current of 0.11 mA and a peak surface power density of 6.2 W/m2 with two TENGs connected in parallel. Furthermore, the power density per unit of wind speed achieves 746 mW/m3·s/m. Consequently, two fluorescent lamps were successfully illuminated and six temperature sensors were continuously lit by the CCR-TENG. The reported CCR-TENG significantly improves low-speed environmental wind energy utilization and demonstrates broad application prospects for in-situ power supply of distributed wireless transmission devices and sensors in the era of the IoT.

A high-performance triboelectric-electromagnetic hybrid wind energy harvester based on rotational tapered rollers aiming at outdoor IoT applications

Anemometers play an important role in environmental monitoring in remote and unique locations, such as forests, islands, and mines. Self-powered wind speed sensors offer a solution for long-term reliable monitoring in unmanned environments. However, current self-powered wind speed sensors suffer from limited integration, limited start-up range, and insufficient output power. Therefore, an all-in-one self-powered wind speed sensor (ASWS-sensor) with a wide start-up range and high output power is proposed. The ASWS-sensor, based on triboelectric nanogenerator and electromagnetic generation technologies, features a unique dual-cup structure that integrates wind speed sensing and wind energy harvesting. This design enables wind speed detection across a broad range from 1.5 to 15 m/s and achieves a high output power of 1.18 W. To meet the long-term, reliable wind speed monitoring needs in coal mine tunnels, a real-time wind speed monitoring and alarm system is developed combining the ASWS-sensor and a master computer. Notably, in this system, the use of the FIR filtering algorithm effectively suppresses significant noise encountered during the collection of single-electrode triboelectric signals with a microcontroller, thereby simplifying the wind speed calculation process. The results show that when the wind speed exceeds 7 m/s, the system can collect, process, wirelessly transmit, analyze, and display wind speed-related data without the need for an external power supply. This demonstrates the excellent application potential of the ASWS-sensor in unmanned monitoring in remote and unique scenarios.

With the widespread application of sensor networks, traditional power supplies face limitations, especially in remote marine areas where battery replacement is challenging and lifespan is limited. As a clean and renewable energy source, wind energy offers a promising solution to this issue. But conventional turbines are bulky, costly, and inefficient at low wind speeds for micro sensors. This study proposes a hybrid triboelectric-electromagnetic wind energy harvester (H-TEWH) that integrates an electromagnetic generator (EMG) with a triboelectric nanogenerator (TENG) to enable synergistic energy harvesting across varying wind speeds. At 11 m/s, the device achieves a theoretical peak output of 12.08 mW. An efficient power management circuit, combining a gas-discharge-tube-based buck circuit and an LTC3588 module to ensure stable and continuous power output. Self-powered sensor experiments validated the practicality and reliability of the system in complex marine environments, providing a feasible technical solution for self-powered devices suitable for maritime monitoring applications.

The triboelectric nanogenerator shows a broad application potential in wind energy collection and wind speed sensing. However, it is difficult to realize wind energy collection and real-time wind speed monitoring in one simple device without external power support. Here, a high-performance dual-mode triboelectric nanogenerator is proposed to simultaneously collect wind energy efficiently and monitor wind speed in real time, which is composed by an alternating current triboelectric nanogenerator (AC-TENG) and a direct-current triboelectric nanogenerator (DC-TENG). Based on the material optimization, the charge density of the AC-TENG improves by a factor of 1 compared with previous works. Moreover, benefiting from the elastic structure and material optimization to realize a low friction force, the AC-TENG shows an excellent durability and obtains a retention of 87% electric output after 1 200 000 operation cycles. Meanwhile, thanks to the high charge density and low friction force, the energy-harvesting efficiency of the AC-TENG is doubled. In addition, the DC-TENG not only displays an excellent real-time sensing performance but also can provide gale warning. Our finding exhibits a strategy for efficiently collecting wind energy and achieving fully self-powered and real-time wind speed monitoring.

Wind conditions are crucial in agricultural production, and wind vectors play a significant role in agricultural planting plans. However, traditional anemometers rely on external power sources such as lithium batteries, while wind energy in farmlands is usually neglected. This paper proposes an intelligent wind vector monitoring system based on a dual-module triboelectric nanogenerator (DM-TENG), which consists of a fan-blade type soft-contact triboelectric nanogenerator (FBTSC-TENG) and a disc-shaped triboelectric nanogenerator (DS-TENG). FBTSC-TENG collects wind energy in the environment to power the temperature and humidity sensors, while determining wind speed through the frequency of voltage pulses. DS-TENG can monitor wind direction, identifying 8 wind directions through output pulse signals and deep learning algorithms. Therefore, the DM-TENG proposed in this study is expected to play a significant role in the field of smart agriculture in the future.

Disc and cylinder‐based triboelectric nanogenerators (TENGs) have great potential for harvesting wind energy. However, a significant challenge faced by these TENGs is the wear issues arising from the required close contact between tribo‐materials, especially at high frequencies. In response to this challenge, a gear‐slider TENG (GS‐TENG) is designed to transition from continuous close‐contact friction mode to intermittent contact. Working in unison with the central gear and two sliders, four units housed within GS‐TENG yield electrical output through periodic contact and separation. During a durability test of 845 000 cycles, the short‐circuit current only experiences a slight decrease, going from 25.38 to 24.03 µA, retaining 94.68% of its initial value. Operating at a matched impedance of 6 MΩ, GS‐TENG at M1 achieves a peak power density of 386 mW m−2, exceeding some previously proposed solutions in wind harvesting. When integrated into a wind speed sensing system, the GS‐TENG has a wide sensing range (13.1 to 28 m s−1) with a maximum error of 3.39%. This work demonstrates a rotation‐to‐translation strategy that lays the foundation for long‐term, high‐frequency wind energy harvesting and the development of a self‐powered wind sensing system.

In June 2023 Swiss people voted a new climate law that set a net-zero emission goal to be reached by 2050 via a full energetic transition from fossil fuels to renewables. The country’s Energy Strategy estimates that 7% (4.3 TWh) of future total renewable energy will be supplied by wind turbines, which requires an increase in the number of installed devices from the 37 currently operating to 760. Such an objective presents numerous challenges as available space is limited by technical restrictions, the country’s complex terrain, and competition with other types of land use.Thanks to qualities like small size and weight, low noise emission levels, and the ability to operate with winds blowing from any direction at relatively low speed (> 2 m/s), vertical axis wind turbines (VAWTs) installed in urban areas are an attractive alternative to overcome the issues associated with large wind farms. Despite this, the potential for wind energy micro-generation in complex urban settings remains largely unexplored.Private households use one third of all energy consumed in Switzerland, and residential renewable energy generation currently consists almost exclusively of photovoltaic (PV) panels which, in 2021, represented 78% of all solar systems operating in the country. No similar statistics are available for residential wind energy generation. Even in the scientific literature, current understanding of the interaction between wind and urban areas is limited, and the knowledge about urban wind resources is markedly inadequate to address the challenges posed by climate change to both local and global energy sectors.Here we use use the Weather Research and Forecast (WRF) model to simulate mean near-surface wind speed over the cities of Lausanne and Geneva to assess the potential for wind energy generation. We perform simulations at 300 m grid spacing and across 85 vertical model levels, with hourly output interval throughout one entire year to identify diurnal and seasonal wind speed trends. We then use power curves of select VAWTs to translate mean wind speed data into potential electrical output maps and time series, over all model cells classified as urban.  Our results show that mean wind speed is generally higher in Lausanne than in Geneva, especially at nighttime. Diurnal cycles evolve markedly differently between the two cities, although differences are at times minimized due to seasonal changes. The average potential for wind energy harvesting using VAWTs in urban environments varies with turbine size and geographical area. The average daily total energy generation potential is one order of magnitude greater in Lausanne compared to Geneva. In Lausanne, top generation is expected during the nighttime across most months, allowing for a good integration of photovoltaic generation. The opposite happens in Geneva where already lower peak wind speed, and associated energy generation, always culminate during the afternoon.This research highlights the potential for urban wind energy micro-generation, drawing attention to the role of regional differences and the need and the importance of numerical simulations for quantitative assessments at the city and regional scales.

Natural cotton-based triboelectric nanogenerator as a self-powered system for efficient use of water and wind energy

Hybrid harvesting of wind and wave energy based on triboelectric-piezoelectric nanogenerators

Humidity-resistant triboelectric nanogenerator and its applications in wind energy harvesting and self-powered cathodic protection

As an important green energy in our life, natural wind energy is widely used in power generation. Triboelectric nanogenerator (TENG) can convert wind energy in the environment into electrical signal. In this study, two independent TENGs in parallel (FHS-TENG) and the power management circuit composed of passive self-switching circuit and LC filter circuit constitute a self-supplying system, which is committed to harvesting wind energy in the environment and outputting stable voltage and improving energy storage performance. The self-switching circuit mainly includes rectifier module, energy storage module, the self-switching module, and filter module. And the on/off state of the passive self-switching is mainly controlled by two transistors, which implements the effect of switch. The results demonstrate that the energy stored by the power management circuit is more than 100 times higher than that of the universal circuit at 100 μF capacitor, and the calculator is in stable working order in simulated wind conditions. This work provides a new strategy for the passive electronic switch of TENG and the improvement of circuit energy storage performance, which is meaningful for the further application and industrialization of TENG.

Study of wind energy harvesting based on rolling bearing type triboelectric nanogenerator