Simulation and the monte carlo method

A copula-based joint deficit index for droughts.

Quantifying the global wave power resource

Hydrodynamic and hydromagnetic stability

Wave energy is arguably one of the most promising renewables. Less developed at present than other renewables, the existing models to estimate the costs of a wave energy project are often oversimplified, and the resulting scatter in the economic assessments weighs on the confidence of potential investors and constitutes therefore an impediment to the development of wave energy. Indeed, understanding the costs of wave energy is one of the main fields of research in marine renewable energy. In this context, the main objective of this paper is to review all the factors that must be considered in an economic analysis of wave energy, including a number of elements that are usually overlooked. In the process we characterise the direct and indirect costs of a wave farm – preliminary costs, construction, operation and maintenance and decommissioning cost – as well as its prospective incomes. For each of them a reference value is presented, together with a generic formula for its calculation. Moreover, the levelised cost, i.e., the production cost of an energy unit (1 kW h), is compared between various energy sources, and on these grounds conclusions on the profitability and competitiveness of wave energy are drawn. In sum, this work reviews the state of the art and sets the basis for a thorough economic analysis of wave energy.

The economics of wave energy: A review

A multivariate model of sea storms using copulas

In the present paper, we investigate the feasibility of wave electricity production in Italian seas by the deployment of the Seabased wave energy converter (WEC). A numerical model of the coupled buoy-generator system is presented, which simulates the behavior of the wave energy converter under regular waves of different wave heights and periods. The hydrodynamic forces, including excitation force, radiation impedance and hydrostatic force, are calculated by linear potential wave theory, and an analytical model is used for the linear generator. Two buoys of different radii are considered to explore the effect of buoy dimension on energy conversion and device efficiency. The power output is maximized by adding a submerged object to the floating buoy, in order to bring the system into resonance with the typical wave frequencies of the sites. The simulation results show a very good agreement with the published data on the Seabased WEC. The model is used to estimate energy production at eight Italian offshore locations. The results indicate that the degree of utilization of the device is higher than 20% at the two most energetic Italian sites (Alghero and Mazara del Vallo) and that it can be considerably increased if the floating body is connected to a submerged object, thanks to the resonant behavior of the WEC. In this case, the degree of utilization of the device would be higher than 40% at most of the study sites, with the highest value at Mazara del Vallo. The work enlarges the perspective, to be confirmed by experimental tests and more accurate numerical modeling, on clean electric power production from ocean waves in the Italian seas.

https://www.mdpi.com/1996-1073/6/6/3033/pdf

Modeling of a Point Absorber for Energy Conversion in Italian Seas

Turbulent Rayleigh-Benard convection produces fields of intense updrafts and downdrafts that are responsible for much of the vertical heat transport. These structures, called plumes or thermals, have horizontal scales comparable to the thicknesses of the boundary layers in which they arise. In the three-dimensional numerical simulations reported here, we have observed that convective plumes organize themselves into clusters with horizontal scales that grow with time and reach the width of the computational domain. In this two-scale process, kinetic energy is transferred mainly to low horizontal wave numbers while the sizes of individual plumes remain on the scale of the boundary layer thickness.

Giuseppe Passoni

Papers

A multivariate model of sea storms using copulas

Modeling of a Point Absorber for Energy Conversion in Italian Seas

Clustering of plumes in turbulent convection.

Large scale patterns in Rayleigh-Benard convection

Wave electricity production in Italian offshore: A preliminary investigation