Investigation of a Novel Wave Energy Generator Using Dielectric Elastomer

2021 ◽  
Author(s):  
Changqing Jiang ◽  
SEIKI CHIBA ◽  
Mikio Waki ◽  
Koji Fujita ◽  
Bettar El Moctar
Keyword(s):  
Wave Energy ◽  
Dielectric Elastomer

scholarly journals A broadbanded pressure differential wave energy converter based on dielectric elastomer generators

2021 ◽  
Author(s):  
Michele Righi ◽  
Giacomo Moretti ◽  
David Forehand ◽  
Lorenzo Agostini ◽  
Rocco Vertechy ◽  
...  
Keyword(s):  
Wave Energy ◽  
Large Deformations ◽  
Dielectric Elastomer ◽  
Wave Energy Converter ◽  
Pressure Differential ◽  
Design Stage ◽  
Small Scale ◽  
Energy Converter ◽  
Wide Range ◽  
The Waves

AbstractDielectric elastomer generators (DEGs) are a promising option for the implementation of affordable and reliable sea wave energy converters (WECs), as they show considerable promise in replacing expensive and inefficient power take-off systems with cheap direct-drive generators. This paper introduces a concept of a pressure differential wave energy converter, equipped with a DEG power take-off operating in direct contact with sea water. The device consists of a closed submerged air chamber, with a fluid-directing duct and a deformable DEG power take-off mounted on its top surface. The DEG is cyclically deformed by wave-induced pressure, thus acting both as the power take-off and as a deformable interface with the waves. This layout allows the partial balancing of the stiffness due to the DEG’s elasticity with the negative hydrostatic stiffness contribution associated with the displacement of the water column on top of the DEG. This feature makes it possible to design devices in which the DEG exhibits large deformations over a wide range of excitation frequencies, potentially achieving large power capture in a wide range of sea states. We propose a modelling approach for the system that relies on potential-flow theory and electroelasticity theory. This model makes it possible to predict the system dynamic response in different operational conditions and it is computationally efficient to perform iterative and repeated simulations, which are required at the design stage of a new WEC. We performed tests on a small-scale prototype in a wave tank with the aim of investigating the fluid–structure interaction between the DEG membrane and the waves in dynamical conditions and validating the numerical model. The experimental results proved that the device exhibits large deformations of the DEG power take-off over a broad range of monochromatic and panchromatic sea states. The proposed model demonstrates good agreement with the experimental data, hence proving its suitability and effectiveness as a design and prediction tool.

scholarly journals Hardware-in-the-loop simulation of wave energy converters based on dielectric elastomer generators

Meccanica ◽  
2021 ◽  
Vol 56 (5) ◽  
pp. 1223-1237
Author(s):  
Giacomo Moretti ◽  
Andrea Scialò ◽  
Giovanni Malara ◽  
Giovanni Gerardo Muscolo ◽  
Felice Arena ◽  
...  
Keyword(s):  
Wave Energy ◽  
Large Scale ◽  
Low Cost ◽  
Test Site ◽  
Dielectric Elastomer ◽  
Operating Conditions ◽  
Polymer Materials ◽  
Hardware In The Loop ◽  
Wave Energy Converters ◽  
Energy Converters

AbstractDielectric elastomer generators (DEGs) are soft electrostatic generators based on low-cost electroactive polymer materials. These devices have attracted the attention of the marine energy community as a promising solution to implement economically viable wave energy converters (WECs). This paper introduces a hardware-in-the-loop (HIL) simulation framework for a class of WECs that combines the concept of the oscillating water columns (OWCs) with the DEGs. The proposed HIL system replicates in a laboratory environment the realistic operating conditions of an OWC/DEG plant, while drastically reducing the experimental burden compared to wave tank or sea tests. The HIL simulator is driven by a closed-loop real-time hydrodynamic model that is based on a novel coupling criterion which allows rendering a realistic dynamic response for a diversity of scenarios, including large scale DEG plants, whose dimensions and topologies are largely different from those available in the HIL setup. A case study is also introduced, which simulates the application of DEGs on an OWC plant installed in a mild real sea laboratory test-site. Comparisons with available real sea-test data demonstrated the ability of the HIL setup to effectively replicate a realistic operating scenario. The insights gathered on the promising performance of the analysed OWC/DEG systems pave the way to pursue further sea trials in the future.

Control of an oscillating water column wave energy converter based on dielectric elastomer generator

2018 ◽  
Vol 92 (2) ◽  
pp. 181-202 ◽  
Author(s):  
Gastone Pietro Rosati Papini ◽  
Giacomo Moretti ◽  
Rocco Vertechy ◽  
Marco Fontana
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
Dielectric Elastomer ◽  
Wave Energy Converter ◽  
Oscillating Water Column ◽  
Energy Converter

Dielectric elastomer wave energy harvester with self-bias voltage of an ancillary wind generator to power for intelligent buoys

2022 ◽  
Vol 253 ◽  
pp. 115178
Author(s):  
Xiaozhen Du ◽  
Lixiang Du ◽  
Xing Cai ◽  
Zhenfu Hao ◽  
Xiangdong Xie ◽  
...  
Keyword(s):  
Bias Voltage ◽  
Wave Energy ◽  
Energy Harvester ◽  
Dielectric Elastomer ◽  
Wind Generator ◽  
Self Bias

scholarly journals Advances in the development of dielectric elastomer generators for wave energy conversion

2020 ◽  
Vol 117 ◽  
pp. 109430 ◽  
Author(s):  
Giacomo Moretti ◽  
Miguel Santos Herran ◽  
David Forehand ◽  
Marco Alves ◽  
Henry Jeffrey ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Wave Energy ◽  
Dielectric Elastomer ◽  
Wave Energy Conversion

scholarly journals Analysis and Design of an Oscillating Water Column Wave Energy Converter With Dielectric Elastomer Power Take-Off

2015 ◽  
Author(s):  
Giacomo Moretti ◽  
Gastone Pietro Papini Rosati ◽  
Marco Alves ◽  
Manuel Grases ◽  
Rocco Vertechy ◽  
...  
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
Mechanical Energy ◽  
Dielectric Elastomer ◽  
Wave Energy Converter ◽  
Irregular Waves ◽  
Electrostatic Energy ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Analysis And Design

In this paper, we present a concept of near/off-shore Oscillating Water Column (OWC) Wave Energy Converter (WEC) that is equipped with a Power Take Off (PTO) unit based on Dielectric Elastomer Generators (DEGs). DEGs are soft/deformable generators with variable capacitance able to directly convert the mechanical energy that is employed for their deformation into electrostatic energy. The proposed WEC is based on an existing tubular collector chamber of an OWC system designed by the company Sendekia, that is combined with an Inflatable Circular Diaphragm (ICD) DEG. This simplified design presents a very reduced number of moving parts showing potentially high efficiency, reliability and noise-free operation. A multi-physics dynamic model of the system is built using time domain linear hydrodynamics coupled with an analytical non-linear electro-hyperelastic model for the DEG-based PTO. The power matrix of the system is calculated for both regular and irregular waves. Some design issues are introduced showing that the electro-elastic response of the DEG provides the system with an additional stiffness that adds up to the hydrostatic stiffness and affects the resonance of the WEC. As a consequence, the geometric shape/dimensions of the OWC chamber and the layout of the DEG diaphragm should be chosen using an integrated procedure aimed at tuning the overall response of the WEC to the spectra a reference wave climate.

Field Experiments on Dielectric Elastomer Generators Integrated on a U-OWC Wave Energy Converter

2018 ◽  
Author(s):  
Felice Arena ◽  
Luca Daniele ◽  
Vincenzo Fiamma ◽  
Marco Fontana ◽  
Giovanni Malara ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Water Column ◽  
Wave Energy ◽  
Field Experiments ◽  
Dielectric Elastomer ◽  
Wave Energy Converter ◽  
Ocean Engineering ◽  
Energy Converter ◽  
Relief Valve ◽  
Natural Period

This paper describes the results of an experimental campaign conducted on a U-Oscillating Water Column (U-OWC) wave energy converter equipped with Dielectric Elastomer Generator (DEG) Power Take-Off (PTO) system. The considered PTO technology has the potential for overcoming some of the limitations associated with the use of traditional self-rectifying turbines. Experiments have been performed in the benign sea test site of the Natural Ocean Engineering Laboratory (NOEL), where the DEG/U-OWC was exposed to sea states with a significant wave height in the range of 0.15 m – 0.45 m and peak spectral periods in the range of 1.8 s – 3.3 s. The aim of this work is to analyze the dynamic response of the coupled DEG-PTO and U-OWC system. The analysis of the experimental data shows that the presence of the DEG determines a slight decrease in the natural period of the water column oscillations. Through the tests, we also demonstrate that a relief valve can be successfully used to actively tune the dynamic response of the system to ensure the safety of the DEG in severe sea-states.

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