When one of the world’s largest energy companies identifies solar, wind and nuclear as targets for diversified investment, advocates of ocean energy might just feel despondent.

Similarly, when former US vice-president and Nobel prize-winning politician Al Gore places so much faith in solar power during his sequel documentary, An Inconvenient Sequel, one might expect a note of disappointment in Prof Tony Lewis’s voice.

However, Lewis is optimism undimmed when it comes wave and tidal potential. The fact that Saudi Arabia’s Aramco would identify sun and wind as priorities for diversification into renewables is as much about geography as the fact that solar and wind costs are falling.

“Of course, money is going into solar in the short term, as the Chinese have filled the market with cheap solar cells,” Prof Lewis says. “And there has been significant increase in interest in solar farms in Ireland.”

“But by 2050, we are going to need everything we have got to reach Paris climate agreement targets, and that has to include wave and tidal energy, solar, wind and biomass,” he says. “For wave and tidal potential, geography is definitely on our side.”

Dubbed Ireland’s “ocean energy daddy” and with a penchant for bow ties, Prof Lewis is emeritus Beaufort professor at University College Cork, and principal investigator at the State’s Marine Renewable Energy Ireland centre (MaREI) .

He is also host of next week’s European Wave and Tidal Energy conference in Cork – regarded as one of the world’s leading forums for this sector.

“When the first of these conferences was held in Greece, about 60 people attended. Ireland hosted the fifth of these in 2003, and there were about 160 registered,” he recalls. “We have over 450 registered for this one, and more people inquiring every day.”

Marine resources

The EU has set a target of 100 gigawatts of energy from marine resources by 2050. Some of the 366 papers and 78 parallel sessions listed for the conference in University College Cork, Cork City Hall and MaREI in Ringaskiddy will be debating how this can come about.

To put the European target in context, Ireland’s total annual generation capacity of energy from all sources is 10 gigawatts, and more than 85 per cent of that is imported.

“We need to develop our indigenous energy so that we have security of supply, but also to exploit the incredible market opportunity presented by the 100 Gigawatt target,”he says. “If you think of it, nearly two gigowatts of that 10 is from onshore wind, and the ocean could produce the balancing seven gigowatts if the entire west coast of Ireland was developed for same.”

Six years ago, an SQW Energy study for the Sustainable Energy Authority of Ireland and Invest Northern Ireland forecast that the island of Ireland ocean energy sector could be producing a net present value of €9 billion, creating “several thousand jobs”, by 2030. German engineering major Siemens estimated that this island’s offshore and onshore wind, wave and tidal resource accounted for one-third of all such potential in western Europe.

There’s a danger in overly ambitious targets and false optimism, however, as several early pioneers in the sector discovered to their cost. Prof Lewis acknowledges that there are still technical challenges, from anchoring to storage of excess power. An interim review of the State’s offshore renewable energy development plan is due this year.

Advances

At the same time, there have been many advances, with wind and solar costs below those of fossil fuel electricity in some parts of the world, and developments in biogas to create a liquid fuel from carbon dioxide and hydrogen, Prof Lewis notes.

“So we are going to have a combination of different ways of using energy, with batteries for storage making more sense in small communities – like Pacific islands, which may become niche developers of ocean energy,” he says.

“Smartgrids which combine wave energy and storage and different types of production, allowing for exporting excess, will also suit smaller communities,” he says. “Electronics allow this to happen.”

He points to the progress in tidal energy made by OpenHydro, founded in 2004 and employing some 120 people in Dublin and Carlingford, Co Louth.

“It is now selling tidal energy turbines in France and Canada, and building a factory in northern France,” Prof Lewis says. “Tidal stream energy offers less opportunities as a resource here, but the technology is simpler, so you could see large arrays of these turbines deployed very soon.”

“Similarly, Cork company Ocean Energy has been testing a 500kw device at the US Navy test site in Hawaii, with funding from the US and the Sustainable Energy Authority of Ireland,” he says.

Next step

The Cobh company had initially tried its smaller scale technology at the Marine Institute’s test site in Galway Bay, and this 500kw device is the next step. It may then be deployed at the ESB International West Wave project off the Clare coast, he says.

“Both Ocean Energy and Sea Power are hoping to overcome the challenges of developing proper anchoring/mooring systems, working with other Irish companies,” he says.

The progress, or otherwise, of adequate planning legislation is another one of those loose ends. A Maritime Area and Foreshore (Amendment) Bill has been listed as a “priority” for several Dáíl terms. The legislation is driven by the EU’s “blue growth” strategy, and gives new powers to Bord Pleanála and coastal local authorities.

“I guess it has to be fit for purpose, and that includes communities,” Prof Lewis acknowledges. “It is a matter of balancing use of the marine environment for energy, fishing, aquaculture and tourism – to everybody’s satisfaction.”