The wave energy is having more and more interest and support as a promising renewable resource to replace part of the energy supply, although it is still immature compared to other renewable technologies. This work presents a complete analysis of the wave energy technology, starting with the characterisation of this global resource in which the most suitable places to be exploited are showed, and the classification of the different types of wave energy converters in according to several features. It is also described in detail each of the stages that are part in the energy conversion, that is, from the capture of the energy from the waves to the extraction of a proper electrical signal to be injected to the grid. Likewise, existing offshore energy transmission alternatives and possible layouts are described.

Review of wave energy technologies and the necessary power-equipment

An apparatus including a plurality of adjacent repeated base units, each base unit formed from an active electrode of first, second and third touch sensor arrays, the first, second and third touch sensor arrays each including a plurality of active electrodes connected to a respective common terminal of the touch sensor array, wherein each base unit includes an active electrode of the second touch sensor array interlaced between an active electrode of the first touch sensor array and an active electrode of the third touch sensor array such that a swipe touch gesture applied to two or more adjacent active electrodes of the apparatus generates signalling at the respective common terminals of the corresponding touch sensor arrays which allows the direction of the swipe touch gesture to be determined.

Apparatus and associated methods

The utilization of renewable energy sources is a vital aspect for development of sustainability. Currently, an unexploited energy source is ocean waves. Various types of wave energy converters (WECs) are able to transform the motion of the waves into electricity. During the last 30 years, a wide range of prototypes was presented with different rates of success. The aim of this survey is to give an overview of how WECs are categorized [operation principle and power takeoff (PTO) system] and show what are the most important criteria that have to be kept in mind when designing a WEC. A few important WECs are described and evaluated.

Wave Energy Converter Concepts : Design Challenges and Classification

Advancements of wave energy converters based on power take off (PTO) systems: A review

Ocean waves are a promising source of renewable energy In this paper, we briefly introduce the characteristics of ocean wave energy and summarize the principles of harvesting ocean energy by wave 

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Review of control strategies for wave energy conversion systems and their validation: the wave-to-wire approach

Dielectric Elastomers are well known for there performance as actuators, but these materials can be used effectively as generators. Research on this field have received considerable attention lately, several prototypes were built like wavepower and human kinetic power generators. The focus of this paper is how the dielectric elastomer can be used as generator. The paper presents a dynamic model to calculate the capacitance of the electroactive polymer according to the external loading and investigates and compares several energy harvesting cycles based on the energy gain.

Energy harvesting using dielectric elastomers

From an electrical point of view dielectric elastomers are variable capacitors, which are frequently used as generators. The focus of this paper is to show, how the maximum energy gain can be realized by realizing an innovative current waveform to charge and discharge the polymer. Several energy harvesting cycles are introduced and their energy output compared. The most promising cycle has been optimized to increase its production while taking several limiting factors into account.

Optimizing the dielectric elastomer energy harvesting cycles

EeFarm-II is used to evaluate 13 different electrical systems for a 200 MW wind farm with a 100 km connection to shore. The evaluation is based on component manufacturer data of 2009. AC systems are compared to systems with DC connections inside the wind farm and DC connection to shore. Two options have the best performance for this wind farm size and distance: the AC system and the system with a DC connection to shore. EeFarm-II is a user friendly computer program for wind farm electrical and economic evaluation. It has been built as a Simulink Library in the graphical interface of Matlab-Simulink. EeFarm-II contains models of wind turbines, generators, transformers, AC cables, inductors, nodes, splitters, PWM converters, thyristor converters, DC cables, choppers and statcoms.

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A Wind Farm Electrical Systems Evaluation with EeFarm-II

Smart materials used as generators have received considerable attention lately and several prototypes were built to demonstrate the process. The focus of this paper is to show how the dielectric elastomers can be used as variable capacitor generator, how the maximum energy gain can be withdrawn from the system by realizing an innovative current waveform to charge and discharge the polymer. The paper presents a dynamic model to calculate the capacitance of the electroactive polymer according to the external loading and investigates and compares several energy harvesting cycles based on the energy gain. Several energy harvesting cycles are introduced and their energy output compared. The most promising cycle has been optimized to increase its production while taking several limiting factors into account. By obtaining this optimized innovative current waveform, a suitable power electronics converter can be designed for a real application.

Balazs Czech

Papers

Wave Energy Converter Concepts : Design Challenges and Classification

Energy harvesting using dielectric elastomers

Optimizing the dielectric elastomer energy harvesting cycles

A Wind Farm Electrical Systems Evaluation with EeFarm-II

Energy harvesting using dielectric elastomers