An Introduction To Wave Power
The Motivation Behind The Project
When Alexander Graham Bell invented the telephone in 1875, little could he have known of the dominance communications research would have over 20th century electronic engineering. All research needs support and influence from the outside world and for communications systems there was no bigger driving force than the pursuit of military superiority. By the time the century was over the biggest technological innovation of our time was with us - the internet - the result of increased military engineering research into robust communications during the cold war.
With this in mind then, anyone paying a visit to the MEng research poster presentations last week may have noticed that all is not what it used to be. The 21st century has brought a new leading influence to engineering – a world energy crisis. More than a quarter of the projects on display come under the category of energy research. There were projects on energy efficient housing, safe disposal of radioactive waste and portable energy scavenging. There were also two projects on renewable energy – one about wind turbines and another on wave energy converters (WECs). If you came at the right time you would have seen my project team stood by the latter.
Given that world fossil fuel supplies will run out, despite the fact that no one can agree on when that will be, renewable energy’s only competition is with itself. This could not have been made any clearer than when our poster was positioned six feet away from the one created by the wind energy team. This leads to the big question for us to answer – why wave power? Ultimately this will come down to the differences between wave energy and its major rivals – wind and solar.
One important difference between wave power and its competition is the quantity of research pursued to date, and hence its scale of adoption by the market. Wave energy was dealt a cruel blow in the 1980s which effectively halted research for almost 20 years. Stephen Salter at the University of Edinburgh had developed ‘Salter’s Duck’, a WEC which could produce electricity from waves with around 80% efficiency. Unfortunately an independent paper was published analysing the device which contained a calculation overestimating the cost of Salter’s renewable energy by a factor of ten. This miscalculation went unnoticed until surprisingly recently, and cast a shadow over the whole project. Then, on the 19th March 1982, Thatcher’s government met in secret, reportedly with members from the nuclear and fossil fuel industries, and the UK Wave Energy program was officially shut down.
The result of these missing years is significant. If you were to picture a solar panel it would be a square of blue cells. Imagine a wind turbine and it would be a large upright with rotating fins attached – rather like an emaciated wind mill. You may even be so specific as to think that it probably has three fins. But what do you picture if you think of a wave energy converter? I imagine you draw a blank - and to a certain extent so did we. There are devices out there in development – enough to actually separate them into five completely different categories (see diagram below) – but deployed devices producing electricity for general consumption are few and far between. To a certain extent then, wave power is playing catch up. The energy market will almost certainly continue to choose its technology in pence per kilowatt hour and on these terms wave power currently doesn’t cut it. This is a shame given the huge amount of energy sat there bobbing up and down. The sea is effectively an enormous collector of wind power. The generated waves contain more energy available in a given area of sea than any similar column of air – in some areas enough to simultaneously boil 20 kettles from just one meter of wave crest. The problem is not the amount of energy or the means of capturing it, it’s essentially one of barriers of entry into a market flooded with more developed and therefore cheaper renewable technologies.
The specific aim of the Warwick Wave Power project is to attempt to inject a step decrease in the cost of wave energy conversion by analysis of the key factors affecting its cost – ease of maintenance, cost of deployment and its ability to survive the strongest of storms at sea. This has given us a new light in which to analyse both the full range of existing devices and a number of original designs developed during the three months that the team has been working on the project.
Alexander Graham Bell did not invent anything like the internet in the 1870s and I would hope that similarly industry does not let the decisions of the 1970s limit the scope for energy technology come the end of the 21st century.