Wave Power
Wave power involves converting the energy in ocean surface waves into electricity using devices either fixed to the shore, the seabed or floating out at sea. Wave energy varies with time, depending on when and where the winds and storms that drive the waves occur. Tidal energy is more regular and predictable.
Two wind zones affect New Zealand. South-east trade winds dominate in the north, enlivened an occasional cyclone from the tropics. The rest of the country is dominated by the roaring forties, a broad band of westerly winds that span the middle latitudes of the southern hemisphere. The roaring forties extend over most of the southern part of the Tasman Sea and the Southern Ocean. These winds produce some of the stormiest seas in the world, with maximum wave heights regularly exceed 4 metres.
| Average wave height around New Zealand |
On average, ocean waves in New Zealand deliver about 25 kW to each metre of coastline. The west and south-west coasts have the country’s most energetic waves. Even on windless days, swells that were generated in the Southern Ocean still arrive. Less wave energy arrives at the north-east coast, because it is sheltered from the south-west waves (click the link on the right for a diagram). The amount of energy in a wave is proportional to the square of its height, so a two metre wave contains four times the energy of a one metre wave.
Wave Energy Technology - New Zealand (WET-NZ) is a Government-funded research and development collaboration programme between Industrial Research Limited, a Crown Research Institute, and Power Projects Limited, a privately owned Wellington-based company. The programme seeks to develop a wave energy device that generates electricity from both the kinetic and potential energy available in open ocean waves. In 2010 WET-NZ received resource consent for half-scale prototype testing at two test sites.
Read more about this topic: Ocean Power In New Zealand
Famous quotes containing the words wave and/or power:
“I hear
the tide turning. Last
eager wave over-
taken and pulled back
by first wave of the ebb.”
—Denise Levertov (b. 1923)
“A speech is poetry: cadence, rhythm, imagery, sweep! A speech reminds us that words, like children, have the power to make dance the dullest beanbag of a heart.”
—Peggy Noonan (b. 1950)