Riding the waves to sustainable energy

I've posted quite a few stories on technologies designed to generate electricity from ocean waves recently. There is a great deal of interest in this concept but as one venture capitalist who specializes in "green investments" commented at a forum I attended last week notes until one or two of these begins to emerge from the pack, investors will probably continue to sit tight and wait for things to sort themselves out a bit more. (GW)

Entrepreneur makes waves with renewable energy

Michael Whelan's invention could use stormy Galway Bay to generate electricity 300 days a year serving hundreds of Irish homes

By Michael Pollitt
The Guardian
September 20, 2007

If Michael Whelan's dream comes true, the Atlantic ocean will soon help keep the lights on in Ireland. And if it does, it will complete a circuit for Whelan: 30 years ago he was a commercial diver working on North Sea oil and gas installations. Returning to Ireland in the 1980s, he started a marine towing and salvage company. After selling that business, he opened a quayside hotel in Cobh near Cork. But now he has returned to the sea - to generate electricity from wave power.

His enthusiasm for the project, a wave energy converter called an Ocean Energy Buoy, knows no limits. While everyone else was celebrating Christmas Day last year, Whelan was mooring his 28-tonne prototype in Galway Bay. Over the next eight months, the quarter-scale model was battered by storms.

Whelan felt like a fish out of water when he opened The Waters Edge Hotel on the quayside at Cobh - and the lure of the sea soon grew irresistibly strong. "Building a hotel was great fun but when I started selling food and beds to people, I knew I was in the wrong business," Whelan says. "I had an interest in renewable energy and I needed to get my feet back into the water."

Turbine drivers

He then met Dr Tony Lewis of the Hydraulics and Maritime Research Centre at University College Cork, who in turn introduced him to oscillating water columns which drove turbines to generate electricity. Inspired by what he saw, Whelan promptly funded further research and formed a technology company - Ocean Energy - in 2002. "We were going forward to try and develop a floating structure to capture wave energy," says Whelan, who later sold his hotel.

Over the past five years, Whelan has pioneered wave technology in Ireland with the assistance of the Hydraulics and Maritime Research Centre, the Irish Marine Institute, and Queens University Belfast. He started with a 1:50 scale model, working up to the latest quarter-scale device. He even took a 1:15 scale prototype to France for tank testing.

The current quarter-scale buoy - 12 metres long, six metres wide and six metres high - was built using the data obtained from earlier models. In section, the Ocean Energy Buoy is an L-shape lying on its back with a vertical oscillating water column. The wave motion alters the subsurface pressure to drive air in and out. This movement is harnessed by a Wells air turbine - the only moving part - which turns the air flow into a continuous rotary action in one direction.

After a 200-mile tow from Cork, the Ocean Energy Buoy was moored in Galway Bay in a spot chosen to match - for scale - the conditions that a full-sized version will face. It looks more like a small barge than a buoy.

"She's very strongly built. The front end is blunt and the back end is open to the sea. When she lifts and falls, she acts like a jet boat and the mooring forces go flat," Whelan says. "On New Year's Eve, we had one of the worst storms in Galway Bay in over 20 years." After riding out the storm unscathed, the buoy spent the next eight months collecting air flow, pressure, and mooring force data. Although not fitted with a Wells turbine, the trial confirmed that a commercially viable source of electricity was possible.

Whelan recently retrieved the buoy from the sea for cleaning and a fresh coat of paint. And now he's installing a small 16-kilowatt power generation system for a further trial. "It's a modified Wells turbine that we will be putting in," says Whelan, who reckons a modest metre of wave motion will generate two or three kilowatts. "If we're satisfied with what she's pumping out, we'll be immediately going to build a full-scale prototype."

Weighing 600 tonnes, this will be 40 metres long, 20 metres wide and 16 metres high. Twin 750 kilowatt Wells turbines are planned, with the combined 1.5MW output sufficient to power hundreds of homes. Are there many calm days in a year, though?

Total dedication

"Along the west coast of Ireland, I think we'll be generating for easily 300 days if not more," Whelan says. Ocean Energy Buoys would be moored in groups in depths of between 30 and 50 metres with the power going ashore via submarine cable. The predicted payback time for a full-scale buoy is seven or eight years.

Getting this far has demanded total dedication from Whelan. On the day he spoke to the Guardian, he was cleaning barnacles and mussels off the prototype, typical of his hands-on approach. His vast experience in deep sea diving, tugboats, and marine salvage has proved invaluable. "If you love your job, it doesn't seem like work at all. But at the same time, I'm not doing it for the love, I'm doing it to make it commercial," Whelan says.

Supported by grants from the Irish Marine Institute and Sustainable Energy Ireland, the research programme has cost more than €1m (£692,570). Whelan is hoping for a good return on his personal investment.

Dr Tony Lewis of the Hydraulics and Maritime Research Centre believes that Ireland is well placed to exploit wave power. "Ireland is on the edge of a large ocean so we're exposed to some of the biggest waves in the world. There is a continuous flow of energy into the coastline which is almost equal to the electricity consumption of the whole country in a year," he says. The Irish government has committed to producing 500MW from wave energy by 2020.

The energy expert Professor Ian Fells has also been involved with marine energy systems. As a former chairman of the New and Renewable Energy Centre in Blyth, he appreciates the challenges faced by the Irish developers. "What encourages me is that it's a fairly simple device and it uses proven technology for generating the electricity," Fells says. "It just remains to be seen how it works and what it costs to bring the power ashore."

Although the Irish government seems inspired by wave energy, Fells worries that the UK government is neglecting marine renewables - tidal stream, wave energy, and tidal barrage - in favour of wind: "Marine technologies are important but the [UK] government has a blind spot. It seems to have put all its eggs into the wind basket and wind is turning out to be very expensive. Wave power has a very important part to play."