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In just a decade New Zealand may be drawing on the sea to supplement its energy supply.
Marine energy technology, also known as blue energy, is being developed overseas and there is growing interest in it here.
Our large coastline means the country would be well placed to
draw on the power of the sea and marine energy could contribute significantly to energy supply needs.
Waves generated by the "roaring forties" winds in the Southern Ocean and Tasman Sea hit the western and southern coasts and it is estimated they could produce an average wave power of more than 100 kilowatts per metre of wavefront.
Energy Minister David Parker has called for applications for funding to investigate potential wave and tidal generating devices for use here.
A marine energy deployment fund would offer grants of up to $2 million a year for the next four years.
Mr Parker said the intention was to get wave and tidal energy generating devices in the water to get some practical experience of what worked and its impact in the marine environment.
He said technological developments were making it more practical to harness solar and wind energy so he was confident of finding practical ways to harness marine energy.
"We're pushing the development of this technology because marine energy is the next logical step in the development of new sustainable and renewable energy sources."
A wide range of options for marine energy generation was being developed internationally, and most were offshore and underwater.
Mr Parker expected the first devices to be working by 2010.
Andrew Laing, executive member of the Aotearoa Wave and Tidal Energy Association, hoped the funding would make it cost effective to develop some pre-commercial marine energy devices.
Mr Laing said the marine energy industry was still nascent, about where wind generation development was 15 years ago, but systems were working overseas.
An oceanographer, Mr Laing said there were challenges in developing marine energy, given the extreme environmental conditions the devices had to cope with.
"There is salt water and an energetic environment."
But other energy sources such as wind had similarly presented challenges that were overcome.
Mr Laing said projects to investigate marine energy here could include inventing devices or bringing in models from overseas to test or adapt to the local environment.
Already about 80 marine energy prototypes were working worldwide.
Mr Laing saw a positive future for marine energy with opportunities to both harness power from tidal currents and the "lively wave action" particularly around the western and southern coasts.
"There is a lot of raw energy to be captured."
New Zealand had a relatively small tidal range, generally less than two metres, but some of the larger harbours on the west coast of the North Island had significant movements of water.
Locations with significant tidal currents included Cook Strait and Foveaux Strait.
Eeca, the Energy Efficiency and Conservation Authority, says at least four marine energy projects have significant work underway and more than 20 groups or individuals are looking at its potential.
