A mobile agent strategy for grid interoperable virtual organisations

During the last few years much effort has been put into developing grid computing and proposing an open and interoperable framework for grid resources capable of defining a decentralized control setting. Such environments may define new rules and actions relating to internal Virtual Organisation (VO) members and therefore posing new challenges towards to an extended cooperation model of grids. More specifically, VO policies from the viewpoint of internal knowledge and capabilities may be expressed in the form of intelligent agents thus providing a more autonomous solution of inter-communicating members. In this paper we propose an interoperable mobility agent model that performs migration to any interacting VO member and by traveling within each domain allows the discovery of resources dynamically. The originality of our approach is the mobility mechanism based on traveling and migration which stores useful information during the route to each visited individual. The method is considered under the Foundation for Intelligent Physical Agents (FIPA) standard which provides an on demand resource provisioning model for autonomous mobile agents. Finally the decentralization of the proposed model is achieved by providing each member with a public profile of personal information which is available upon request from any interconnected member during the resource discovery process

From grids to clouds: a collective intelligence study for inter-cooperated infrastructures

Recently, more effort has been put into developing interoperable and distributed environments that offer users exceptional opportunities for utilizing resources over the internet. By utilising grids and clouds, resource consumers and providers, they gain significant benefits by either using or purchasing the computer processing capacities and the information provided by data centres. On the other hand, the collective intelligence paradigm is characterized as group based intelligence that emerges from the collaboration of many individuals, who in turn, define a coordinated knowledge model. It is envisaged that such a knowledge model could be of significant advantage if it is incorporated within the grid and cloud community. The dynamic load and access balancing of the grid and cloud data centres and the collective intelligence provides multiple opportunities, involving resource provisioning and development of scalable and heterogeneous applications. The contribution of this paper is that by utilizing grid and cloud resources, internal information stored within a public profile of each participant, resource providers as well as consumers, can lead to an effective mobilization of improved skills of members. We aim to unify the grid and cloud functionality as consumable computational power, for a) discussing the supreme advantages of such on-line resource utilization and provisioning models and b) analyzing the impact of the collective intelligence in the future trends of the aforementioned technologies

Cost modelling of floating wind farms with upscaled rotors in Maltese waters

The technical viability of offshore wind projects depends upon a number of factors such as the site-specific wind resource, sea depth, seabed composition, distance to the shore and climatic conditions amongst others. The Mediterranean is characterised by deep seas relatively close to the shore and only a reasonable wind climate if compared to conditions in countries that are forerunners in the offshore wind sector. The development of floating wind turbine support structures will allow wind farms in deeper waters and will be a catalyst for the wider diffusion and larger-scale implementation of offshore wind farms on a global level. This study investigates the prospects for a hypothetical 100 MW floating offshore wind farm well to the west of the island of Malta. The study models three upscaled turbines having rotor diameters of 126, 145 and 170 m. The study shows that the rotor upscaling process can improve the economic viability of offshore wind turbines with the improved energy yield counterbalancing the higher investment costs required for such a project and thus resulting in a lower cost of energy. The levelised cost of electricity is estimated to be in the 21.0 to 23.6 €cent/kWh range which, although still well above the current market prices of electricity generated by conventional means, is expected to drop considerably over the coming years as new international players enter the offshore wind market. Increasing levels of competition, new concepts coming to fruition and wider and larger-scale diffusion of new technologies will help bring down costs of energy for the offshore wind farms of the future.Bajada New Energy, General Membrane, EcoGroup, Econetique, Energy Investment, JMV Vibro Blocks, Solar Engineering, Solar Solutionspeer-reviewe

Analysis of a novel offshore platform with integrated energy storage operating in Central Mediterranean waters

A thermodynamic model of a novel energy storage device is described and simulated in the context of a central Mediterranean climate. The device uses a hydro-pneumatic concept to store energy as compressed air. It is designed to be integrated into an offshore floating platform. The thermodynamic model illustrates the behaviour of the compression process and the heat exchange with the surrounding environment. Different rates of compression are simulated, and it can be observed that faster compression rates lead to higher gas temperatures and pressures. The sensitivity to climatic conditions is also investigated, however this effect was seen to be minimal. A simplified Black-Box Model is also developed, with its parameters obtained through a curve-fitting process. Finally, a stochastic input is fed to both models and a comparison is made. The simplified model results in a minor over-prediction of the efficiency.peer-reviewe

Analysis of a novel offshore platform with integrated energy storage operating in Central Mediterranean waters

A thermodynamic model of a novel energy storage device is described and simulated in the context of a central Mediterranean climate. The device uses a hydro-pneumatic concept to store energy as compressed air. It is designed to be integrated into an offshore floating platform. The thermodynamic model illustrates the behaviour of the compression process and the heat exchange with the surrounding environment. Different rates of compression are simulated, and it can be observed that faster compression rates lead to higher gas temperatures and pressures. The sensitivity to climatic conditions is also investigated, however this effect was seen to be minimal. A simplified Black-Box Model is also developed, with its parameters obtained through a curve-fitting process. Finally, a stochastic input is fed to both models and a comparison is made. The simplified model results in a minor over-prediction of the efficiency.peer-reviewe