SEAWAVE stands for Simulation Engineering Applied to Wave Analysis, Validation and Estimation. I put forward this proposal in 2009 under the Enterprise Ireland Commercialisation Fund Proof of Concept scheme. It did not proceed, partly because there was a view in my own institute that the idea was not sufficiently developed and that adequate groundwork in seeking commercial backers had not been done.

Summary

The Ocean Wave Energy Resource (OWER) is capable of providing wave-power-derived electricity to make up a significant proportion of energy needs in Ireland and other countries. Effective exploitation of the resource depends on a detailed knowledge of its characteristics and variability. An ability to accurately forecast generating capacity would be particularly valuable to commercial operators.

The research aim is to provide rapid and accurate engineering modelling and simulation to enhance the efficiency and profitability of exploitation through answering questions, resolving problems, optimizing performance, testing concepts etc. in relation to the Ocean Wave Energy Resource and, most importantly, allowing forecasts of generating capacity to be made.

A set of simulation modelling tools and methodologies (SEAWAVE) will be developed to assist with validating wave data from test sites, performing economic evaluations of the OWER, assessing and quantifying the Irish OWER, performing operational conditions analysis and, especially, ocean wave power predicting and forecasting. The underlying principles of OWER are mainly those of mechanics and thermodynamics and SEAWAVE will be founded on these.

Currently, operators of wave energy systems are hampered in making operating decisions by the limitations of available data. The proposed modelling and simulation technology would seek to provide effective answers to questions commercial operators might ask, such as the following:

• Given wave data at test sites and from data buoys, can you demonstrate and confirm that the data are self-consistent and that therefore data at other locations that are not instrumented can be implied within a specified tolerance with a specified degree of confidence?
• Can you evaluate the annually available wave energy for a specified ocean area and characterize its variability?
• Can you generate descriptions of operational conditions by location and time period, including the ability to forecast these conditions from available global data?
• Can you demonstrate that the location-specific OWER can be forecast within a specified range of variability and with a specified degree of confidence from available global real-time data?
• To what extent is a given geographical region of OWER (such as the Irish region) sensitive to OWER or other exploitation activities or potential activities outside that geographical region?

The Approach

This proposal is to demonstrate the technical feasibility of answering such questions as posed above by means of a set of simulation and modelling tools (SEAWAVE). The simulation and modelling will be developed primarily using Wolfram Mathematica and Microsoft Excel. The approaches to be used have evolved from experience with other research projects. A modular and very flexible development process will be achieved and a high standard of presentation and self-documentation will be maintained for all parts of the work.

The set of simulation tools and methodologies for the ocean wave energy resource will centre on a macro model of the Earth, including a macro model of the Irish region. This will be developed from first principles to model the OWER, as distinct from the weather or any other aspect of the environment. The Earth’s surface and the Irish region will be divided into patches and calculations will be performed for each patch involving the wind speed and direction and the swell-wave and wind-wave spectrum for the patch. Respect for the energy balance equation will be fundamental within the model. The patches for the Irish region will be smaller than those for the Earth’s surface.

Successful completion of this project would offer significant advantages for any OWER-exploiting companies that choose to avail of the technology. Commercially, the technology could be offered for license and as a service, but would preferably be the core of a spin-out company. The proof-of-concept package to be developed would be used to promote the technology to prospective licensees and clearly present the system’s advantages. Market analyses by suitable external consultants may be considered at a later stage to help with clear identification of initial customers.

Existing Approaches in 2009

In 1955 the US Naval Oceanographic Office (Pierson et al.) published the book ‘Practical methods for observing and forecasting ocean waves’, which dealt with the theory of wave generation, wave propagation and forecasting of sea waves and swell waves. In 1957 Neumann and Pierson published ‘A detailed comparison of theoretical wave spectra and wave forecasting methods’. The emerging science was well-established.

In 2002 Dennis Whitford of the Department of Oceanography, U.S. Naval Academy, Annapolis, Maryland, USA, published a two-part paper entitled ‘Teaching ocean wave forecasting using computer-generated visualization and animation’. Part 1 dealt with sea forecasting, while part 2 dealt with swell forecasting. MATLAB software was used. The current proposal will make use of computer-generated visualisation. Wolfram Mathematica will be used principally, but there may also be a role for MATLAB.

In 2003 Wang et al. of the Ocean University of Qingdao, China, proposed a spatial evolution equation for air-sea interactions and wave prediction that can be used in the modelling of the generation and growth of wind waves.

In 2006, Vethamony et al. described ‘Wave modelling for the north Indian Ocean using MSMR (Multi-channel Scanning Microwave Radiometer) analysed winds’ in the International Journal of Remote Sensing.

Peter Janssen of the European Centre for Medium-Range Weather Forecasts (ECMWF) has provided ongoing updates through papers, articles and presentations relating to the understanding of atmosphere-ocean interaction; for instance, he was a participant at a workshop on ‘Atmosphere-Ocean Interaction’, which was held at ECMWF from 10 to 12 November 2008. There does not appear to have been any focus on OWER.

Swell and surf forecasting currently exist in an advanced form: at the time of writing the proposal in 2009 excellent one-week animated forecasts were available, for example, at https://www.wavewatch.com. This proposal is to demonstrate the feasibility of using this type of data-and-simulation-based forecasting in relation to exploiting the OWER, rather than in relation to surfing.

Wolfram Mathematica has been used for modelling of tsunamis, e.g. https://library.wolfram.com/infocenter/Demos/5699/

Mathematica provides a very powerful development and documentation environment for this proof-of-concept proposal. The proposal is for a solution to engineering problems, based on Mechanical Engineering, Energy Engineering and Simulation Engineering expertise. The ultimate aim is to maximize the efficiency of exploitation of the OWER for commercial companies. The elements of the set of simulation modelling tools and methodologies will be selected and retained on the basis of their contribution to the accuracy of the answers required. Borrowing from Albert Einstein’s expression: SEAWAVE will be ‘as simple as possible, but no simpler’.

A fully developed simulation and modelling system will allow Industry to develop and implement new technological solutions to effectively exploit the Ocean Wave Energy Resource. At the time of writing the proposal no competing simulation technology that was targeted specifically at this sector was available.