Original article by Susan Ballard. Read the exciting story of one man’s realisation of an engineering idea to help harness the power of the Earth’s oceans.

Introduction

If you've ever stood in a choppy ocean being battered by waves, or watched surfers careering through the foam, you'll know how powerful the sea can be. But have you ever wondered how it would be if we could harness that energy and turn it into electricity? One person who has spent the past 35 years answering that question is Alan Wells, FRS, inventor of the Wells turbine which is now being used in the first commercial wave generation plant in the world. This is his story as told Susan Ballard of the Environmental Change Institute.

 

Sections in this article

• An engineer's view of the sea

• Progress and Setbacks

• Where Next?

An engineer's view of the sea

"The idea first occurred to me when I was a frequent ferry traveller from Stranraer to Belfast. The North Channel was invariably rough and I got interested in wave motion. I thought, there's a lot of energy, why not make use of it."

It was 1965 and Alan Wells had a chair in Structural Science at Queen's University, Belfast. He was leading a project on composite structures but some of his research students became more interested in how to extract power from wave motion. The basic idea was to use air displaced by the motion of the waves to drive a turbine. However, as the crests and troughs create a reciprocating motion it looked as if a switch from blow to suck was required. That would have led to a more complicated device and as Wells says,

"The sea is a very wild place. You don't place intricate machinery in the sea. It'll just go wrong."

So the challenge was to build a turbine that could cope with the change in airflow. As a mechanical engineer Alan Wells had also been interested in autogyros. He realised that helicopter blade motion permits the reversal of airflow up or down. Applying the same principle to the turbine he realised it would work if the blades were "zero incidence", in other words, set in the plane of rotation.

Helicopter technology was applied in the wave turbine

The first application of this technology was used by a firm in Northern Ireland that built equipment for yachts and small boats. They realised that they could use it on navigation buoys to charge the batteries for the lights.

"It was perfect for the purpose. The turbine can rotate at high speed, doesn't keep stalling and stores kinetic energy. The prototype installed in Belfast Lough went for two years without being touched and the same technology I believe is still in use in China and Japan."

Progress and Setbacks

"Living through the 1974 oil crisis and of course what happened on September 11th 2001 makes us realise, that we are much too dependent on petroleum, too dependent on coal. That's how I became interested in renewable energy. Sustainability is an obvious thing if one has any belief that there's a future in the human race, which I do."

The costs of the materials needed for his composite structure work also quadrupled taking away any economic advantage of the research so his funders, The Wolfson Foundation, agreed to transfer their grant to his renewables project.

The turbine at Queens University, Belfast.

In 1977 Wells and his students built a sizeable but not full scale 30 kW turbine which they put together at the Queen's Biological Centre in Strangford Lough.

"It was all very exciting and got a lot of publicity because it was so big, the size of a lorry, that we couldn't get it out without the help of an RAF helicopter."

At about this time circumstances conspired to send Wells back to his other base in Cambridge which put his wave power work on ice for the next ten years.  Meanwhile, wave power lost much of its Government support.

"Having read the published work of an investigative journalist, I believe wave power was too much of a threat to the nuclear industry so that the support was withdrawn."

Now however, wave power is very much on track and Wavegen, the company which is using the Wells turbine in a multimillion-pound project, has international backing.

"I remember the first million going in, that was an exciting time. We had given a presentation in Zurich to a Swiss group. The Group Chairman, Mr. Schmidheiny, who had an international reputation for embedding sustainable principles into all aspects of industrial processes and products, asked us what we wanted next. My colleague said one million. He said, I think we can do it. That was an exciting moment"

On another happy note the project is also benefiting from the years of research Alan Wells put into composite structures. A combination of metal, polymers and glass fibre is being used to build the next prototype floating plant structure thereby resisting the corrosive nature of salt water. 

Where Next?

On ClimateX.org

To get some idea of how wave energy sits in the context of Renewable energy as a whole and to read about the story of wave energy development in the UK see ‘Wave Energy: An Overview'.

External Links

Take a look at the Wavegen website.