EVIBES Energy Harvesting from Natural and Anthropogenic Vibrations: Preliminary results

The search for new energy solutions aims to provide reliable, sustainable and cost-effective energy to communities worldwide. One possible option for green energy is the use of low-amplitude mechanical vibration as a renewable energy source. Mechanical vibrations have the potential to be converted into electricity, providing a clean energy solution. The energy yield from such vibrations is determined by their amplitude and frequency, which vary with different natural or anthropogenic sources.  

The first objective of this presentation is to introduce the E-VIBES project, a highly ambitious initiative that seeks to investigate the potential of mechanical vibrations as an energy source. In the E-VIBES project, we are investigating natural and anthropogenic vibration sources, evaluating their potential based on magnitude, frequency, and frequency of occurrence. Subsequently, we intend to design and construct an energy harvester using appropriate technologies such as piezoelectric or electromagnetic mechanisms tailored to the selected vibration sources. The device will be tested in the field to evaluate its efficiency and feasibility in generating electricity from mechanical vibrations. Finally, a socio-economic analysis will be conducted to evaluate the potential societal impact of the energy harvester. An important element in the design process will be to find solutions that drive down costs and increase accessibility for as many technologies and communities as possible. 

As a second objective, we present the first results of E-VIBES dedicated to harvester modeling. Finite element modeling (FEM) using COMSOL was used to determine how to design the resonant frequency, i.e., the optimum operating frequency, for a cantilever piezoelectric energy harvester (PEH) by varying the component configuration, device geometry, and proof mass loading. The study includes unimorph and bimorph geometries and devices based on macro (bulk) and micro (micro-electromechanical systems (MEMS)) scale materials. Preliminary results show that the resonant frequency and thus the power output can be tailored by the PEH design, e.g. by engineering the cantilever geometry and by tuning the proof mass. The current design study shows that realistic ceramic-based PEH designs tend to operate at significantly higher frequencies than those for naturally occurring vibration sources.  

Finally, we present the first results of the potential power output by analyzing the seismic waveforms of natural earthquakes and induced blasts recorded in northern Chile in 2015 using a short-period, three-component, continuous-recording seismic network with an average station spacing of about 500 meters. To do this, we use a kinetic energy approximation that allows us to analyze the seismic amplitudes and velocities to obtain quantifiable energy values according to the magnitude and duration of the event. This approximation is used as input to model the physical parameters of the harvester, such as the amplitude and frequency of natural vibrations.