Arthur Pecher - Handbook of Ocean Wave Energy

Department of Civil Engineering, Aalborg University, Thomas Manns Vej 23, 9220 Aalborg , Denmark

The widespread usage of affordable electricity converted from ocean waves would be a fabulous achievement. Besides that the wave energy converting (WEC) technology would be particularly interesting, it also would have several significant benefits to society, such as:

As the world energy needs will keep on increasing while the fossil fuel reserves are depleting, wave energy will become of significant importance. The demand for it will start when its price of electricity will be right and will then only increase with time.

In general, there are three key elements to a successful product innovation. It has to be technically feasible, economically viable and desirable/useable by an end-user. In other words, it requires a new functional technology that has a positive business case and that is of use for society. These key elements do not necessarily require being developed at the same time since a developer needs to start somewhere. However, they need to be present in some kind of harmony before an innovation can successfully be launched on the market (Fig. ).

There is a great demand for renewable energy and a need to diversify the renewable energy mix. This can easily be seen on the significant annual increase in global investment in renewable energy, such as wind and solar. Wave energy has even been additionally stimulated in some countries as they recognise its benefits and great potential. The technology push came mainly in the form of public grants and capital investment in technology development, while the market pull through public market incentives, such as revenue support (the feed-in tariffs) []. This indicates that the usability and desirability (or human value) are currently very positive.

An impressive amount of wave energy technologies have been developed over the last 25 years. To give an indication hereof, the list of current wave energy developers at EMEC counts 256 developers [).

The last missing factor for production innovation success is the business potential or economic viability of the wave energy technologies within the frames of the market (with or without incentives). The business case is made based on cost (CapEx and OpEx) and power production calculations (read more in Chaps. ). To be able to demonstrate a positive business case, a significant amount of proof (for the calculation) and thereby experience with the WEC is expected to be gathered before. Although some investors can be convinced on the way in the great business potential of a WEC, it will probably still require a decent track record of an offshore full-scale WEC before it will convince a larger market. This is particularly difficult to realise with WECs since the development cost is particularly high (e.g. compared to wind energy) and the development process long. This is especially due to the harsh offshore environment, which requires special equipment and vessels and which is not easily accessible. So, the development process requires a careful balance between technology optimisation and physical progress. The best advice is, therefore, to keep on investigating the economic potential along the development progress as there is no reason to progress if it is absent.

WECs are machines that are able to exploit the power from ocean waves and to convert it into a useable form of energy, such as electricity.

Ocean waves are theoretically relatively well understood and extensively described in literature. However, in practice, it is very difficult to accurately describe, reproduce and predict the exact environmental conditions at a certain offshore location. This is due to its complexity and the large amount of environmental parameters that can have a significant influence on it (read more about this in Chap. ).

In Fig. , the different metocean parameters affecting the marine environment are sketchily presented, together with the primary sub-systems of a (floating) WEC.

Most WECs, even the ones with different working principles (see Chap. ).

The main sub-systems that are present in (all) WECs have also been introduced widely in literature [] and consist of: