The wind energy in cities cannot be exploited effectively because natural wind is unstable and complex. Therefore, a triboelectric-electromagnetic hybrid generator with swing-blade structures (SBS-TEHG) was designed to effectively harvest intermittent and continuous wind energy in an urban environment. First, the spring structure and base were considered to realize the maximum output performance of triboelectric nanogenerators. Then, the computational fluid dynamics method was applied to optimize the structure of the SBS-TEHG to improve its aerodynamic performance. The starting wind speed of the SBS-TEHG was 2 m/s, and its energy conversion efficiency was 9.04%, 159% higher than that of the SBS-TEHG without guide plates at 4 m/s. The results demonstrated that the SBS-TEHG lit 105 light-emitting diodes (LEDs) under the intermittent-wind harvesting mode at a wind frequency of 1 Hz when the single swing blade operated, while a wireless PM_2.5 & PM₁₀ sensor was powered by the SBS-TEHG after a period of operation under the continuous-wind harvesting mode. The findings of this study provide a novel solution for low-speed wind energy harvesting in cities and demonstrate the potential of SBS-TEHG as a distributed energy source.

The hydrokinetic energy of river current, as one of the essential and widespread renewable energies, is difficult to be harvested in low flow velocity and shallow water areas. In this work, a three-dimensional (3D) fully-enclosed triboelectric nanogenerator (FE-TENG) with bionic fish-like structure for harvesting hydrokinetic energy is reported, which is comprised of the triboelectric power-generation unit, bionic fish-like structure and connection unit. Through the bionic structure, the FE-TENG realizes zero head power generation in shallow water with low flow velocity. What’s more, the effect of external excitations and bionic structures on the electrical performance are systematically studied in this work. The FE-TENG can generate peak power density of 7 and 0.36 W/m³ respectively under the simulated swing state with frequency of 1.25 Hz and simulated river current with flow velocity of 0.81 m/s. In practical applications, due to the 3D fully-enclosed design, the FE-TENG immersed in water for 35 days demonstrates excellent immersion durability with undiminished electrical performance. Therefore, the work proposes an efficient method realizing zero head power generation, and provides a good candidate for long-term service in the river current.