scholarly journals REFOS: A Renewable Energy Multi-Purpose Floating Offshore System

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3126
Author(s):  
Dimitrios N. Konispoliatis ◽  
Georgios M. Katsaounis ◽  
Dimitrios I. Manolas ◽  
Takvor H. Soukissian ◽  
Stylianos Polyzos ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Integrated Design ◽  
Energy Resources ◽  
Offshore Wind ◽  
Mooring System ◽  
Elastic Coupling ◽  
Oscillating Water Column ◽  
Integrated Design Approach ◽  
Resources Exploitation ◽  
Theoretical Results

The present paper deals with the development of a multi-purpose floating tension leg platform (TLP) concept suitable for the combined offshore wind and wave energy resources exploitation, taking into account the prevailing environmental conditions at selected locations along the European coastline. The examined Renewable Energy Multi-Purpose Floating Offshore System (REFOS) platform encompasses an array of hydrodynamically interacting oscillating water column (OWC) devices, moored through tensioned tethers as a TLP platform supporting a 10 MW wind turbine (WT). The system consists of a triangular platform supported by cylindrical floaters, with the WT mounted at the deck’s center and the cylindrical OWC devices at its corners. Details of the modelling of the system are discussed and hydro-aero-elastic coupling between the floater; the mooring system; and the WT is presented. The analysis incorporates the solutions of the diffraction; the motion- and the pressure-dependent radiation problems around the moored structure, along with the aerodynamics of the WT into an integrated design approach validated through extensive experimental hydrodynamic scaled-down model tests. The verified theoretical results attest to the importance of the WT loading and the OWC characteristics on the dynamics of the system.

scholarly journals Joint Environmental Data at Five European Offshore Sites for Design of Combined Wind and Wave Energy Devices

2013 ◽  
Author(s):  
Lin Li ◽  
Zhen Gao ◽  
Torgeir Moan
Keyword(s):  
Renewable Energy ◽  
Deep Water ◽  
Wave Energy ◽  
Environmental Data ◽  
Energy Resources ◽  
Offshore Wind ◽  
Wave Power ◽  
Joint Distributions ◽  
Wave Parameters

The costs for an offshore wind farm, especially with bottom fixed foundations increase significantly with increasing water depth. If costs can be reduced to a competitive level, the potential for wind farms in deep water is huge. One way of reducing costs might be to combine offshore wind with wave energy facilities at sites where these resources are concentrated. In order to design combined renewable energy concepts, it is important to choose sites where both wind and wave energy resources are substantial. Such facilities might be designed in ultimate limit states based on load effects corresponding to 50-year wind and wave conditions. This requires a long-term joint probabilistic model for the wind and wave parameters at potential sites. In this paper, five European offshore sites are selected for analysis and comparison of combined renewable energy concepts developed in the EU FP7 project – MARINA Platform. The five sites cover both shallow water (<100m) and deep water (> 200m), with three sites facing the Atlantic Ocean and the other two sites in the North Sea. The selection of the sites is carried out by considering average wind and wave energy resources, as well as extreme environmental conditions which indicate the cost of the system. Long-term joint distributions of mean wind speed at 10-meter height (Uw), significant wave height (Hs) and spectral peak period (Tp) are presented for selected sites. Simultaneous hourly wind and wave hindcast data from 2001–2010 are used as a database, which are obtained from the National and Kapodistrian University of Athens. The joint distributions are estimated by fitting analytical distributions to the hindcast data following a procedure suggested by Johannessen et al. (2001). The long-term joint distributions can be used to estimate the wind and wave power output from each combined concept, and to estimate the fatigue lifetime of the structure. For estimation of the wind and wave power separately, the marginal distributions of wind and wave are also provided. Based on the joint distributions, contour surfaces are established for combined wind and wave parameters for which the probability of exceedance corresponds to a return period of 50 years. The design points on the 50-year contour surfaces are suggested for extreme response analysis of combined concepts. The analytical long-term distributions established could also be applied for design analysis of other offshore structures with similar environmental considerations of these sites.

Renewable Energy Resources for Better Economics and Sustainable Living in Rural and Desert Areas

2019 ◽  
Vol 10 (12) ◽  
pp. 1165-1171
Author(s):  
Karl Gatterer ◽  
◽  
Salah Arafa ◽  
Keyword(s):  
Renewable Energy ◽  
Poverty Reduction ◽  
Energy Resources ◽  
Green Economy ◽  
Renewable Energy Resources ◽  
Economic Activities ◽  
Energy Materials ◽  
Sustainable Living ◽  
Sustainable Community Development ◽  
Access To Knowledge

Reliable and affordable energy is the key for the socio-economic development in rural and desert communities worldwide. While energy can be used for consumption purposes such as Lighting, Access to Information, Comfort and Entertainment, productive use of renewable energy is the key enabler for SMEs and Economy to grow. The paper examines the complex interactions among Energy, Materials, Water, Food, Building, Employment and Environment. It also discusses the implementation of renewable energy technologies to overcome some of barriers faced by rural villages and desert communities. It shows some of the special applications and approaches used over the past few decades in energy conversion, consumption and conservation to achieve poverty reduction, social justice and sustainable development. Field experiences in Basaisa projects, Egypt showed that open free dialogues with all stakeholders, site-specific education and training, appropriate local financing systems and access to knowledge are key-elements and essential factors for achieving green economy and sustainable community development. The coming decade will see a continued expansion of knowledge about renewable energy resources and its useful applications as systems friendly to the environment and as tools for economic activities, sustainable living and growth in rural and desert communities.

Management of Renewable Energy Resources in India

2012 ◽  
Vol 2 (11) ◽  
pp. 121-124
Author(s):  
Savitha C Savitha C ◽  
◽  
Dr. S. Mahendrakumar Dr. S. Mahendrakumar
Keyword(s):  
Renewable Energy ◽  
Energy Resources ◽  
Renewable Energy Resources

THE ANALYSIS OF OPERATION MODES OF ENERGY STORES IN AUTONOMOUS HYBRID POWER PLANTS WITH RENEWABLE ENERGY RESOURCES

2018 ◽  
pp. 55-67
Author(s):  
S. G. Obukhov ◽  
I. A. Plotnikov ◽  
V. G. Masolov
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Low Frequency ◽  
Rechargeable Batteries ◽  
Energy Resources ◽  
Renewable Energy Resources ◽  
Hybrid Power ◽  
Operation Modes ◽  
Energy Stores ◽  
Energy Store

The paper presents the results of the comparative analysis of operation modes of an autonomous hybrid power complex with/without the energy store. We offere the technique which defines the power characteristics of the main components of a hybrid power complex: the consumers of the electric power, wind power and photo-electric installations (the last ones have been constructed). The paper establishes that, in order to compensate the seasonal fluctuations of power in autonomous power systems with renewable energy resources, the accumulative devices are required, with a capacity of tens of MWh including devices that are capable to provide energy storage with duration about half a year. This allows abandoning the storage devices for smoothing the seasonal fluctuations in the energy balance.The analysis of operation modes of energy stores has shown that for a stock and delivery of energy on time intervals, lasting several hours, the accumulative devices with rather high values of charging and digit power aren't required. It allows using the lead-acid rechargeable batteries of the deep category for smoothing the daily peaks of surplus and a capacity shortage. Moreover, the analysis of operation modes of energy stores as a part of the hybrid complexes has demonstrated that in charging/digit currents of the energy store the low-frequency and high-frequency pulsations of big amplitude caused by changes of size of output power of the renewable power installations and loading are inevitable. If low-frequency pulsations (the period of tens of minutes) can partially be damped due to the restriction of size of the maximum charging current of rechargeable batteries, then it is essentially impossible to eliminate high-frequency pulsations (the period of tens of seconds) in the power systems with the only store of energy. The paper finds out that the combined energy store having characteristics of the accumulator in the modes of receiving and delivery of power on daily time intervals, and at the same time having properties of the supercondenser in the modes of reception and return of impulses of power on second intervals of time is best suited to requirements of the autonomous power complexes with renewable energy resources.

Assessment of bioenergy development potential in agricultural enterprises

2020 ◽  
pp. 165-171
Author(s):  
Iryna Hryhoruk
Keyword(s):  
Renewable Energy ◽  
Large Scale ◽  
Agricultural Waste ◽  
General Structure ◽  
Geographical Location ◽  
Economic Assessment ◽  
Energy Resources ◽  
Industrial Complex ◽  
Renewable Energy Resources ◽  
Energy Potential

Exhaustion of traditional energy resources, their uneven geographical location, and catastrophic changes in the environment necessitate the transition to renewable energy resources. Moreover, Ukraine's economy is critically dependent on energy exports, and in some cases, the dependence is not only economic but also political, which in itself poses a threat to national security. One of the ways to solve this problem is the large-scale introduction and use of renewable energy resources, bioenergy in particular. The article summarizes and offers methods for assessing the energy potential of agriculture. In our country, a significant amount of biomass is produced every year, which remains unused. A significant part is disposed of due to incineration, which significantly harms the environment and does not allow earning additional funds. It is investigated that the bioenergy potential of agriculture depends on the geographical distribution and varies in each region of Ukraine. Studies have shown that as of 2019 the smallest share in the total amount of conventional fuel that can be obtained from agricultural waste and products suitable for energy production accounts for Zakarpattya region - 172.5 thousand tons. (0.5% of the total) and Chernivtsi region - 291.3 thousand tons. (0.9%). Poltava region has the greatest potential - 2652.2 thousand tons. (7.8%) and Vinnytsia - 2623.7 thousand tons. (7.7%). It should be noted that the use of the energy potential of biomass in Ukraine can be called unsatisfactory. The share of biomass in the provision of primary energy consumption is very small. For bioenergy to occupy its niche in the general structure of the agro-industrial complex, it is necessary to develop mechanisms for its stimulation. In addition, an effective strategy for the development of the bioenergy sector of agriculture is needed. The article considers the general energy potential of agriculture, its indicative structure. The analysis is also made in terms of areas. In addition, an economic assessment of the possible use of existing potential is identified.

CURRENT STATE AND PROSPECTS FOR THE DEVELOPMENT OF BIOGAS ENERGY IN UZBEKISTAN

2020 ◽  
Vol 2 (7) ◽  
pp. 171-184
Author(s):  
Z. U. SAIPOV ◽  
◽  
G. A. ARIFDZHANOV ◽  
Keyword(s):  
Renewable Energy ◽  
Organic Waste ◽  
Agricultural Sector ◽  
Renewable Energy Sources ◽  
Energy Resources ◽  
Agricultural Producers ◽  
Biogas Plants ◽  
The Republic ◽  
Rural Producers ◽  
Agricultural Regions

Energy is one of the main pillars of the state’s economy, which is currently facing serious problems due to depletion of mineral energy resources and the threatening environment. As a result, presently around the world there is a rapid growth and development of energy-efficient technologies and the use of renewable energy sources (RES), providing an increase in energy resources, as well as environmental and social effects. One of the most relevant and promising areas of renewable energy development is the disposal and processing of organic waste in biogas plants, and this is particularly relevant in agricultural regions. In this regard, this paper considers the state and prospects for the development of bioenergy in agricultural regions of Uzbekistan, where half of the population of the republic lives. The potential of organic waste from livestock and poultry farming of the agricultural sector was determined, and it was revealed that the use of biogas plants for the disposal of manure and litter is clearly a profitable production and requires close attention from rural producers. The introduction of biogas technologies for the bulk of agricultural producers is an urgent task, that will ensure not only a solution to the waste problem, but it will also provide a solution to energy, agricultural, environmental and social problems in rural regions of the republic.

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