Tidal Power: The Next Wave?

Green: Business

Over the next few years, we can expect to see huge advances in our ability to harness power from the ocean’s waves and tides, a new report from IHS Emerging Energy Research, a Cambridge, Mass., consulting firm, predicts.

A tidal energy turbine developed by Atlantis Resources.Getty Images A tidal energy turbine developed by Atlantis Resources.

Until recently, that sector has had limited popularity and mixed success, even as the number of installations generating power from other renewable resources like the wind, sun and biomass has grown rapidly.

“The global ocean energy sector is at a turning point,” the company’s report says. More than 45 wave and tidal prototypes are expected to be ocean-tested in 2010 and 2011. Only nine were tested in 2009.

More important, perhaps, while previous test projects tended to be operated by small, boutique firms, the giants of hydropower, which have decades of experience drawing power from rivers, are now getting into the ocean business.

Tides are particularly attractive sources of power because they are predictable, unlike sunshine and wind. Not surprisingly, countries with rough seas like Britain and Portugal are leading the way in exploring ocean power.

Portugal, which now gets more than 40 percent of its electricity from renewable sources, was one of the first countries to install a commercial “wave farm.” There, several years ago, a British company used a snakelike device called the Pelamis system to absorb the energy of waves.

The Portugal experiment met with mixed results before it was halted because of financial problems. One stumbling block was that the floating machines that absorbed wave energy quickly broke under the constant assault of the waves.

The European Energy Association estimates that, globally, the oceans could yield more than 100.000 terawatt hours a year if the technology to harness that power can be perfected. That is more than five times the electricity the world uses in a year.