Suchergebnisse

Renewable energy is one of the government's efforts to increase the source of the national electricity supply and reduce fossil energy sources. Indonesia has the potential to develop renewable energy in the fields of ocean waves, sunlight, water, and geothermal. But of all these, the most promising to become renewable energy development opportunities are water energy, geothermal energy and ocean wave energy. Indonesia as an archipelagic country with an area of 1,904,556 km2 which consists of; 17,508 islands, 5.8 million km2 of ocean and 81,290 million km of beach length, the potential for marine energy, especially ocean waves, is very potential to be empowered as new and renewable alternative primary energy, especially for power generation. This ocean wave power plant has been widely developed, including: buoy type technology, overtopping devices technology, oscillating water column technology. Oscillating Water Column (OWC) is an alternative technology to convert ocean wave energy using an oscillating water column system. The ocean wave conversion technology of the OWC system was chosen because it is suitable in areas with steep coastal topography and has a wave height value between 0.2 m to 1.19 m and even exceeds so that the electricity generated is greater. OWC technology which will be developed for the territory of Indonesia has several opportunities and challenges. Opportunities and challenges that will be faced include the potential for waves, the application of OWC to waterways in Indonesia, OWC systems, and technology investment for the prospect of long-term energy development in Indonesia.

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record ; The multi-chamber Oscillating Water Column (OWC) device has recently become more attractive due to its potential high efficiency. In this paper, the hydrodynamic performance of a single-, dual- and triple-chamber OWC-breakwater are investigated experimentally. In the first instance, quantitative comparisons are implemented to understand the hydrodynamic performance of multi-chamber OWC-breakwaters. Specific attention has been dedicated to the hydrodynamic performance of capture width ratio (CWR), reflection coefficient, transmission coefficient, dissipation coefficient and effective frequency bandwidth. The investigation identified various findings that can be summarized as follows: i) hydrodynamic interactions between chambers in the multi-chamber OWC device has improved wave power extraction characteristics; ii) comparing with the conventional pontoon breakwater, the multi-chamber OWC-breakwater showed better wave attenuation performance in longer waves; iii) wave steepness is important for evaluating the performance of the multiple-chamber OWC-breakwater device; and iv) the implementation of the multi-chamber scheme broadens the effective frequency bandwidth (satisfied the condition of KT 0.2) of OWC-breakwater. ; Key Program for International Scientific and Technological Innovation Cooperation between Governments ; National Natural Science Foundation of China ; China Postdoctoral Science Foundation

The article of record as published may be found at https://doi.org/10.1007/s41939-019-00057-y ; This paper investigated energy harvesting from ocean waves using an oscillating column (OC) and a triboelectric nanogenerator (TENG). First, preliminary tests were conducted for a TENG fabricated using copper alloy or pure copper and polytetrafluoroethylene (PTFE) tape. Then, an OC was designed and built with the pure copper TENG, which was tested previously. The final design was tested in a tow tank with a wave maker to demonstrate the OC–TENG system under simulated ocean waves. The study examined different parameters that influenced the power generation, i.e., the voltage of alternative currents, in order to determine what parameters are critical to higher power generation. ; Identified in text as U.S. Government work.

96 Seiten, 64 Abbildungen, Englisch; 22 x 28 cm, Broschur; ISBN 78-3-907236-56-7
Edition Patrick Frey, Zürich 2023, EUR 48,00

The push for carbon-free energy sources has helped encourage the development of the ocean renewable energy sector. As ocean renewable energy approaches commercial maturity, the industry must be able to prove it can provide clean electrical power of good quality for consumers. As part of the EU funded Open Sea Operating Experience to Reduce Wave Energy Cost (OPERA) project that is tasked with developing the wave energy sector, the International Electrotechnical Commission (IEC) developed electrical power quality standards for marine energy converters, which were applied to an oscillating water column (OWC). This was done both in the laboratory and in the real world. Precise electrical monitoring equipment was installed in the Mutriku Wave Power Plant in Spain and to an OWC emulator in the Lir National Ocean Test Facility at University College Cork in Ireland to monitor the electrical power of both. The electrical power generated was analysed for harmonic current distortion and the results were compared. The observations from sea trials and laboratory trials demonstrate that laboratory emulators can be used in early stage development to identify the harmonic characteristics of a wave energy converter. ; This research has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No. 654444 (OPERA project)

This is the author accepted manuscript ; To be competitive against other renewable energy sources, energy converted 1 from the ocean waves needs to reduce its associated levelised cost of energy. It has been proven that advanced control algorithms can increase power production and device reliability. They act throughout the power conversion chain, from the hydrodynamics of wave absorption to the power take-off to improve the energy yield. The present work highlights the development and test of several algorithms to control the biradial turbine which is to be installed in the Mutriku oscillating water column plant. A collection of adaptive and predictive controllers is explored and both turbine speed controllers and latching strategies are examined. AWave-to-Wire model of one chamber of the plant is detailed and simulation results of six control laws are obtained. The controllers are then validated using an electrical test infrastructure to prepare the future deployment in the plant. Finally, the control strategies are assessed against criteria like energy production, power quality or reliability. ; European Union's Horizon 2020

The surface temperatures of the plasma core in the final stages of the first contraction phase of spark-generated bubbles oscillating under ordinary laboratory conditions in a large expanse of water are determined experimentally. The measurement method is based on an analysis of the optical radiation from the bubbles and on the assumption that the plasma core is radiating as a black-body. It is found that the maximum surface temperatures of the plasma core range 4300–8700 K.

The light emitted from the spark-generated bubbles oscillating in water is studied experimentally. Attention is paid to the emission of light from bubbles in the final stages of their first contraction and in the early stages of their following expansion. In some experiments, two close flashes of light were observed. The first light flash has already been studied in earlier works. In the present work, attention is paid to the second light flash. The relations between the first and second flashes of light and the size of the bubbles are studied and discussed in detail. It is assumed that these two light flashes are caused by two different processes taking place in the bubbles. The possible nature of these two processes is briefly discussed.