Sea Change in Renewables Market Forces

New and cheaper ways are rapidly being floated for countries with deep seas off their coasts to exploit the free energy from wind and tidal power.

The race is on to prove that offshore wind power on floating platforms can be a significant power source for coastal states, with more than a dozen designs in development.

All countries with deep seas off their coasts can exploit the technology by anchoring wind farms near their major cities.  Countries supporting these floating power stations include Japan, the US, and European countries bordering the North Atlantic and Mediterranean. Island states with limited land space would also benefit.

There are already successful demonstration platforms in Norway and Portugal, proving that the technology works.  The battle now is to get costs down so that offshore wind can compete with other renewables.

The latest group to claim a breakthrough is the Department of Civil and Environmental Engineering at the Universitat Politècnica de Catalunya (UPC), Spain.  Its developers have designed and patented a floating platform for offshore wind turbines that they claim can reduce energy costs to €0.12 per kilowatt hour (kWh) − less than the cost of electricity from a new nuclear power station.

Efficient design
They say the cost reduction is achieved through more efficient design and the use of concrete rather than steel, reducing costs by 60%.

Climent Molins and Alexis Campos, researchers at the Barcelona School of Civil Engineering, have developed another prototype called the WindCrete, a cylindrical structure with a large float and a ballast base that makes it self-stabilizing.

They say the main innovation of this model is its seamless, monolithic structure.  It is also built of concrete, which is cheaper than steel.  Concrete is said to be more resistant in the marine environment, needing less maintenance and lasting for about 50 years.

The absence of joints in the platform is designed to increase its ability to withstand the effects of wind and seawater, avoiding the damage normally caused by wave action.

The WindCrete includes a 5-megawatt (MW) wind turbine that could be upgraded to carry rotors producing up to 15 MW with a relatively small increase in cost, making it far more economical.

Partially-submerged offshore platforms of this type require a minimum depth:  90 m in the case of the WindCrete.  However, there is no technical maximum depth below which they cannot be installed.  In the Gulf of Mexico, for example, there are floating oil platforms anchored at depths of up to 2,300 meters.

Read more at Sea Change in Renewables Market Forces