Power generation from waves continues to develop as Aquamarine Power has unveiled its new, second-generation Oyster 2 wave power generator. According to the company, "The new 800kW device will measure 26 metres by 16 metres and will deliver 250 per cent more power than the original Oyster 1 which was successfully deployed at the European Marine Energy Centre (EMEC) in Orkney last summer." A test installation is planned for 2011 and will use three wave devices connected to a single power generation station to produce 2.4 megawatts of electricity.

Like the Pelamis wave generator (now, sadly, sitting on the shore for lack of maintenace funds), the Oyster rides on the surface to harness wave power. This means that Oyster cannot coexist with surface vessels, unlike other underwater systems. But, instead of housing the generator at sea, where conditions are harsh and maintenance and repair are costly, the Oyster system harnesses wave power to drive hydraulic systems and on-shore turbines to produce electricity.

The new Oyster incorporates many improvements over the original design, including simplified construction requiring less steel to produce and design to enable easier mass production.  Aquamarine Power expects to deploy Oyster in farms of 100MW generating capacity or more. An animated Oyster video shows more about how the system operates.

via: Inhabitat

Minesto, a spin-off from Swedish automaker Saab, is developing what it calls it's "Deep Green" technology, underwater kites tethered to the ocean floor that could produce continuous energy from tidal flows. A single Deep Green turbine could produce up to 500 kilowatts of electricity. And tides are much more regular than winds, so that the energy produced would be less erratic and variable.

The kites have a 12m (almost 40 ft) wingspan. The kites would remain at least 20m (66 feet) below the surface, to prevent conflicts with ocean navigation and minimize visual impact. Tidal flow as low as 1.6 meters/second can be used to create the lift necessary to move the kite.

Since the underwater kite is anchored to the ocean floor, it is able to move at much faster speeds, which makes the turbine more effective, as it traverses back and forth in order to generate electricity. Although wind-based deepwater offshore power systems are difficult to install and operate, Deep Green tidal kites would be well suited for instalation in deeper waters. Furthermore, the underwater kites are much lighter and easier to install than the equipment needed for other deepwater generation systems. Deepwater generating systems have the additional expense and technical hurdles of transmitting the power over a greater distance. But the higher efficiency and more consistent generation offered by Deep Green could offset those drawbacks.

The company indicates the Deep Green system offers an operating cost of 0.06-0.14 Euros/kWh, as compared to 0.15-0.30 Euros/kWh for other tidal systems, and 0.10-0.12 Euros/kWh for offshore wind systems.

A scale model of Deep Green will be tested in Northern Ireland next year as the next stage of development for this system.

via: Slashdot