Wave Power Gets Creative

The wave power industry is a world full of creative ideas and strange-looking machines, each more innovative (or crazy) than the other. There's no doubt the ocean holds a lot of power. The question is how to convert it to electricity. As many others in greentech, wave power companies and developers have recently seen increasing public interest for wave power (see Surf’s Up: Ocean Power Ascendant).

For example, media interest suddenly became more intense when companies like Apple and Google discussed using wave power and currents to power their facilities.

What follows is a look at some of the many solutions out there, some with huge investments at stake, others still in small-scale testing with only a few investors. The technologies are about capturing the power from waves, currents or tidal currents.

Orecon
Orecon uses an oscillating water column technology and received new venture capital last year to develop its device on a full-scale commercial level. The company was established in 2002 as the offspring of a post-graduate project at the University of Plymouth. It's backed by Advent Ventures, Venrock, Wellington Partners and Northzone Ventures.

Atlantis Resources
Atlantis Resources develops turbines that collect the power of the tidal currents. The Singapore-based Atlantis just received a $14 million investment from Norwegian Statkraft and plans to install tidal power turbines off the Australian coast as well as in Scotland. Atlantis delivers two different turbines. The "Nereus" is targeted for shallow open water and rivers. The water drives a perpendicular chain. The "Solon" is targeted for water deeper than 40 meters and is set up in arrays.

Aquamarine
The wave energy converter from Aquamarine is called The Oyster. It consists of an oscillator that is fixed to the bottom of the sea. The passing waves run through the Oyster and deliver high-pressure water to the shore where hydro-electric generators convert it into electrical power. Aquamarine says ten Oyster energy converters could provide energy to a town of 3,000 homes. Each Oyster delivers 300 kilowatts to 600 kilowatts.

Pelamis
Pelamis has constructed a semi-submerged "sea snake" which consists of cylindrical sections linked together. The wave motion creates movement in the joints between the sections which then move hydraulic rams that pump high-pressure fluid through hydraulic motors. The motors run electrical generators. The power is then fed down a cable to the bottom of the sea which can it be connected with cables from other units and delivered to shore with a single cable. The "snakes" are 180 meters long and 4 meters in diameter. Each machine can deliver 750 kilowatts according to Pelamis. The company has, however, had some recent problems with technical issues and financing. Backing up Pelamis are a number of investors including Emerald Technology Ventures, Norsk Hydro Technology Ventures, BlackRock Investment Managers, 3i, Carbon Trust, Nettuno Power, Tudor BVI Global Portfolio and Scottish Enterprise.

Ocean Power Technologies
Oysters and snakes aside, make way for the Power Buoy. OPT has constructed a buoy that is anchored to the sea. The waves make the buoy move up and down resulting in mechanical stroking being converted into electricity using a power take-off system. According to OPT a 10-megawatt power station would occupy 30 acres of ocean space. Ocean Power has signed two contracts with the Navy worth a total of $4.7 million to test the PowerBuoy's ability to power the Navy's Deep Water Active Detection Systems (DWADS), which track the movement of ocean-going vessels. The company also has a number of deals with companies in Europe and Australia (see Ocean Power Technologies Goes Hawaiian)

AWS Ocean Energy
Scotland's AWS generates power from waves with its Archimedes Waveswing. The device is a buoy anchored to the sea much like the Power Buoy from OCT. The water moves a hydraulic system and motor-generator. AWS is now engineering a 250-kilowatt pre-commercial demonstrator.