Showing papers on "Marine energy published in 2002"

Power from marine currents

Abstract: This paper describes the rationale and the engineering approach adopted for the development of technology for converting the kinetic energy in marine currents for large-scale electricity generation. Although the basic principles involved are relatively straightforward and well understood, being similar to those of a wind turbine, a practical and cost-effective large-scale system designed to extract the kinetic energy of flowing water has yet to be developed. This paper describes the research and development being undertaken through an industrial consortium with the aim of achieving this goal for the first time, i.e. to achieve the world's first commercially viable systems for delivering power from marine currents.

A performance study of a radial turbine for wave energy conversion

Abstract: Bidirectional flow air turbines are used in association with oscillating water columns to convert wave energy available in the oceans into mechanical power. Radial turbines, among others, were studied for such an application. The efficiency of radial turbines using reaction blading was found to be extremely low. On the other hand, the efficiency of impulse-type radial turbines was found to be higher. However, detailed performance studies on impulse-type radial turbines are not found in the literature. This paper presents detailed performance characteristics as well as some parametric studies based on laboratory experiments.

Installation of power generation by ocean wave

Abstract: An installation to apply ocean energy to power generation. The installation includes a floater, lever, chain, ratchet wheel, flywheel, generator, cable, etc. The floater and weight fixed to the floater move up and down with the motion of wave and drive the strength enlargement mechanism made up of a number of levers to travel alternately and pull the heavy flywheel to rotate constantly. The rotation of the flywheel enables the generator to run and yield electricity. The installation has simple structure and high efficiency and can easily increase or decrease the enlargement mechanism according to the capacity of generation. This installation with low cost can be widely utilized for pollution-free power generation in the coast.

Method and installation of power generation by ocean wave

Abstract: The present invention concerns the method and installation to apply ocean energy to power generation. It is consisted of the floater, lever, chain, ratchet wheel, flywheel, generator, cable, etc. It is characterized by the fact that the float and weight fixed to it move up and down with the motion of wave, which drive the strength enlargement mechanism made up of a number of levers to travel alternately and pull the heavy flywheel to rotate constantly. By this way, the generator runs and yields electricity. The present invention has simple structure and high efficiency and can easily increase or decrease the enlargement mechanism according to the capacity of generation. This installation with low cost can be widely utilized for pollution-free power generation in the coast.

Converting ocean energy into electrical energy using bourdon tubes and cartesian divers

Abstract: A system for converting the kinetic energy of the ocean into electrical energy There is presented a water-filled pipe extending from the shore into the ocean The sunken end opens into a water-filled piston sleeve standing upright on the ocean floor The sleeve contains a buoyant piston extending either to the ocean surface or into an internal wave field Since the end of the pipe located ashore ends into either a Bourdon Tube or Cartesian Diver then passing waves or tide action will vary the pressure of the water in the Bourdon Tube or Cartesian Diver Machinery is presented that can convert the elastic potential energy of a Bourdon Tube and Cartesian Diver into kinetic energy to operate an electric generator There is no complicated and expensive electrical machinery offshore, there is no significant movement of mechanical or hydraulic parts offshore and there are no significant friction losses in bringing the energy ashore

Global perspective: Economic forecast for renewable ocean energy technologies

Abstract: Renewable energy sources from the oceans include offshore wind, wave energy, and underwater currents. Sustainable future economies require renewable energy sources. Recent developments in ocean-based renewable energy systems are outlined and forecasts for the next decade are put forth. Offshore wind energy is the fastest growing sector in renewable energy. Anticipated to reach $ 6 billion per year in Europe by 2006, upwards of 86 MW of capacity from 88 turbines are in place today. Capacity by 2010 is projected to grow to at least 2000 MW. Governmental support in Europe is fueling the development, in part, because of greenhouse gas emission targets. The first commercial-scale wave power facility was established in Scotland. Several proponents plan prototype demonstrations over the next few years. Growth in this sector is anticipated to reach $100 million per annum by 2010. Projects harnessing tidal currents have shifted toward capturing tidal-driven coastal currents. Conservative estimates of $40 million per annum by 2010 appear realistic. Ocean-based renewable energy development lag land-based systems because of significant capital requirements and difficulty obtaining the necessary financing due to risk and market barriers. The technical capabilities, both in engineering and management, exist in the offshore sector to undertake the size and scope of projects envisioned.

Offshore tidal power generation--a new approach to power conversion of the oceans' tides

Abstract: Offshore tidal power (OTP) generation is a new approach to tidal power conversion that resolves the environmental and economic problems of the familiar 'tidal barrage' technology. OTP uses a rubble mound impoundment structure and low-head hydroelectric generating equipment situated 1 mile or more offshore in a high tidal range area. Shallow tidal flats provide the most economical sites. Multi-cell impoundment structures provide higher load factors and have the flexibility to shape the output curve to dispatch power in response to demand price signals. The tides are highly predictable and permit tidal power to fit comfortably into existing electricity distribution grids. A computer program is described that uses equipment performance characteristics and tidal data to create a detailed simulation of generation output, water flowss, and storage, and is used for design optimization. The article also contains a history of tidal power and discusses tidal power's place in the renewables market.

Ocean waves: Energy resource assessment

Abstract: The aim of this paper is to provide a general view of wave energy resource assessment. First, a review of the origin of waves and the transformation they undergo as they propagate towards the coast through waters of decreasing depth is presented. Following this, the wave and wave-energy parameters and the statistics required for resource characterization are described. The various types of wave data and their usefulness for the present purposes are summarised. A common methodology for assessment of the wave energy resource is developed. Finally, a general description of the global open ocean resource is presented.

Productivity of Ocean-Wave-Energy Converters: Turbine Design

Abstract: A study was undertaken to identify which of a range of advanced Wells turbine configurations would maximize wave power productivity. The productivity is estimated of a monoplane with fixed guide vanes, a monoplane with variable-pitch blades, and a high- and low-solidity biplane with counterrotating rotors. Two control mechanisms are investigated for the variable pitch configuration. Raleigh distributions based on a mean annual pneumatic power rating of 500 kW are utilized to generate the short and long-term variations of input power to be matched with experimental turbine performance data obtained from a steady-state test rig. It was found that productivity was relatively insensitive to turbine configuration but that a low-solidity counterrotating turbine had the best performance characteristic providing high peak efficiency and gradual onset of stall.

Ocean wave energy utilization

Abstract: The exploitation of ocean waves in electricity production, potable-water production, water-body revitalization and fanning is discussed. Those energy-conversion technologies that are now at the prototype stage are described. The systems are those that are resonant in nature, since resonant systems have been found to be the most efficient. The efficiency of these systems is due to both diffraction-induced wave focusing and possible impedance-matching.

Power from the sea: a plan to develop ocean energy to meet consumer utility needs

Abstract: The Neptune Sciences, Inc. (NSI), Renewable Energy Group has developed a project management plan to develop "Power from the Sea" technologies in well defined phases. Using a multi-phase process, NSI will first provide renewable power solutions to military bases and then to residential communities, state and local businesses. The NSI Renewable Energy Group has focused their project management expertise in three types of renewable energy: Off-shore Wind Turbines (OSWTs); Current/Tide Energy Converters (C/TECs); and Wave Energy Converters (WECs). Solar energy is an area of planned expansion for the group. This paper includes an outline of the NSI Renewable Energy Group project management approach for WEC projects, a discussion of various wave energy technologies, including their states of development and commercialization potential, non-grid connected applications for WECs are discussed including distributed generation, power desalination plants, hydrogen generation, and beach erosion abatement. The NSI Wave Renewable Energy Group consists of experts in weather and wave modeling, environmental permitting, WEC performance modeling for project specific siting plans, and economic modeling, to determine an accurate forecast of the project cost of energy and internal rate of return. NSI uses the Distributed Integrated Ocean Prediction System (DIOPS) to estimate the wave energy in the customer's area of interest, to determine the ocean wave energy resource potential available for a particular customer. DIOPS allows for deep-water waves to be propagated across ocean basins, using the WAve Model (WAM), over the shelf, using a variety of nearshore wave models including Delft Hydraulics Simulating Waves Nearshore (SWAN), the Steady-state WAVE model (STWAVE), and the REFraction/DIFfraction model (REF/DIF). DIOPS can also propagate the resultant wave spectra into the surf zone, via the Navy Standard Surf Model (NSSM). Using an extensive database of WEC developers, NSI is able to determine the optimum performing and economically efficient WECs, which can be employed in the customer's operating area. At the same time, NSI has personnel experienced in obtaining the necessary environmental permits for installing the best performing WEC that conforms to the environmental sensitivities of the area. By using existing commercial technologies, and applying them to the customer's need, NSI is able to develop "green energy" solutions, which meet both the customer's power requirements and monetary budgets.

Air Turbine With Staggered Blad Es For Wave Power Conversion

Abstract: In a self-rectifying air turbine for wave energy conversion, it is reported that the rotor encountered different maximum velocities between the inhalation and exhalation processes of the oscillating water column. This paper describes the development of an efficient turbine suitable for such actual asymmetric flow conditions. The air turbine with staggered blades has been presented and investigated experimentally by model testing under steady flow conditions. The running and starting characteristics under pseudo-sinusoidal oscillating flow conditions were then clarified by using a quasi-steady analysis. As a result, it is found that the air turbine with staggered blades is superior to the Wells turbine, and a suitable choice of design factor has been suggested for the preset angle of the rotor.

Power generator using ocean engergy

Abstract: The utility model is an ocean energy power generation device, comprising a float 1, a chain 2, a sprocket 3, a tensioner 4, a heavy drop 5, an initiative taper gear 6, a driven taper gear 7, a submarine bracket 8, a transmission shaft 9, an air pump 10, an air tank 11, a gas turbine engine 12, a generator 13, a power output terminal 14, a constant pressure valve 15, a pressure gauge 16, a safety valve 17, a drain valve 18, a push rod 19, a rack 20 and a gear 21. The utility model makes comprehensive use of sea tide and wave energy, also can transform tide and wave energy into high pressure gas to store, then transform the high pressure gas into electric energy according to needs. The way is not limit to terrain, the investment and the scale can be possible small or large.

Using the Programmable Logic Controller to Realize the Frequency and Power Automatic Control of Ship Power Station

Abstract: The basic principle of the frequency and power automatic adjustment of marine power station as well as its realizing method of software and hardware are introduced in this paper.

Sea frame float wave energy linkage electric generator

Abstract: The utility model belongs to a generating electrical device which generates electricity by wave power brought from marine energy sources, specifically which relates to an ocean framework floating body wave power linkage electrical machine, the wave power is joined up by a chain axis device and the power is deposited by an inertia wheel, the floating body transmits the entire acquired wave power to the uniform chain axis through an arm and a transmission gear, then the power is exported from the chain axis for the generator to generate electricity. The utility model is a new innovation of the wave power generating electrical device, the device can not only collect and deposit enormous wave energy, but the whole floating body is also stable and safety, which is an optional ocean framework floating body wave power linkage electrical machine on the ocean.

A Source (Of Energy) For Garcia

Abstract: The U.S. Navy maintains a remote installation on the island of Diego Garcia in the Chagos Archipelago, Indian Ocean. This facility uses more than 65 MWh of electricity and 350 M-gal of water annually. Reliability and costs of electricity supply and fresh water quality were concerns of the Navy in 1996. Prospective contractors were invited to submit proposals for provision of these services with some encouragement to use renewable energy resources. As a capstone design project, three teams of 1 st -class midshipmen (seniors majoring in ocean engineering at the U.S. Naval Academy) set about to identify and design an ocean energy system to compete, at least conceptually, with Navy contractors. These teams explored various renewable energy sources such as ocean thermal, wave, and offshore wind energy. In four-months time, each team researched the alternatives and developed a concept design for its selected energy source. Results were presented to a Review Panel consisting of Navy representatives and ocean engineering professionals. Brief details of this capstone experience and educational opportunities in renewable ocean energies at the U.S. Naval Academy are shared later in the paper. Past developments and recent trends in renewable energy from ocean sources are this paper’s principal focus. For example, France currently maintains the most significant ocean energy recovery plant - a 240-MW tidal power facility at La Rance. And, Denmark’s “Energy 21” Plan calls for development of 4 GW of offshore wind power by the year 2030, sufficient to meet more than 25% of that nation’s anticipated consumption of electricity.

Power station simulation subsystem in marine

Abstract: The operating functions of the marine power station are simulated by computer technology and the virtual power plant is also developed in the system. Thus it is possible to realize better natural man machine interaction interface and immersion, completing the function of power station simulation system in marine power plant simulator.