The energy generated from our oceans could be doubled using a new system for predicting wave power, according to researchers from the University of Exeter.
The research, co-written by Tel Aviv University, was published in the journal Renewable Energy and could, according to the scientists pave the way for significant advancements in marine renewable energy, making it a more viable source of power. Currently technologies that extract and convert energy from the sea are not yet as fully developed as solar or wind energy technology. They are as yet not commercially competitive without subsidies. Progress has been made by the leading device developers, but key challenges remain.
Over 70% of the earth’s surface is covered with water. The energy contained within waves has the potential to produce up to 80,000TWh of electricity per year, sufficient to meet our global energy demand five times over. Locations with the most potential for wave power include the western seaboard of Europe, the northern coast of the UK, and the Pacific coastlines of North and South America, Southern Africa, Australia, and New Zealand. In theory power available from wave energy is 1,000 megawatts per kilometer of coastline. In reality, however, only a fraction of this energy can be extracted, in part because wave intensity is highly variable based on the hour, day and season. This is making it difficult to improve the efficiency of energy capture from the waves. The prevention of damage to devices by the hostile marine environment also proves to be a big challenge. The need is to make sure the technology continues to operate in harsh weather circumstances.
According to Exeter scientists, the key to this is to enable devices to accurately predict the power of the next wave and respond by extracting the maximum energy. The team devised a system, which enables the device to extract the maximum amount of energy by predicting the incoming wave. This information enables a programme to actively control the response required for a wave of a particular size. Due to the fact that the device responds appropriately to the force of the next wave, it is far less likely to be damaged and wouldn’t need to be turned off in stormy conditions, as is currently the case.
Co-author Dr Markus Mueller said: “The next step is for us to see how effective this approach could be at a large scale, by testing it in farms of Wave Energy Converters.” There is need for a better understanding of how large wave-energy farms might alter the coastal climate and impact coastal ecology and marine life. Currently underwater noise studies are carried out at the European Marine Energy Center in Scotland.