Neptune’s tidal power concept is a failure

Like the tides, tidal power’s fortunes rise and fall.

Last week we reported on a Tidal Generation-designed 1-megawatt, horizontal-axis turbine’s installation at the European Marine Energy Centre, a move that sealed energy giant Alstom’s purchase of the former Rolls Royce-owned company. But while that deal was coming together, another tidal enterprise was going under.

You might remember the company: Neptune Renewable Energy. A year ago, the company began a demonstration of its Proteus concept at the Humber estuary. Hopes were high, but to put it bluntly, the thing didn’t work.

“The full-scale demonstrator was deployed in the Humber estuary in January 2012 and since that time has been subject to much testing and a number of modifications,” Neptune said in a statement announcing its liquidation.

“The Directors became aware towards the end of last year that the device would not be able to achieve a high enough level of electrical output, despite indications to the contrary resulting from earlier work done at fortieth and tenth scale.”

Tidal power (and its close cousin wave power), unlike wind, is a sector brimming with new concepts and designs. Nobody knows for sure what will work – except now, it seems, we know that a vertical-axis turbine within a duct, as Neptune tried, isn’t the ticket.

“The Directors have been obliged to accept that that the chosen approach is technically flawed and therefore not suitable for the development of commercial arrays,” the Neptune statement went on.

“They have therefore accepted that there is no commercial value in pursuing the project any further. The Directors are confident that all options and approaches have been investigated thoroughly.”

The U.K. is the world leader in marine energy, envisioning getting perhaps 300 megawatts of tidal and wave-generated electricity from the seas by 2020 (right now the figure is a paltry 5 MW).

State support has been fairly robust – in fact, just a few weeks ago the Crown Estate dangled a total £20 million in support for two wave or tidal projects. Projects will need to have a total installed capacity of 3 MW to be eligible, so this support is really intended to try to narrow the field to some designs that can actually be put to work.

“Several wave and tidal stream technologies are now proven and it is timely for the industry to move on to demonstration projects,” the Crown Estate’s Rob Hastings said.

Indeed, as Neptune Renewable Energy found out, it’s only then that a concept’s viability can truly be known.

* Pete Danko, EarthTechling