Offshore wind energy developer Blue H has launched a prototype technology that it says will help overcome the costs and logistical problems of installing wind turbines offshore.

The Holland-based company has developed a submerged deepwater platform (SDP) that is large and stable enough to support a tower and wind turbine, and which can be assembled onshore and positioned in deep waters. The first SDP prototype will soon be anchored off the coast of southern Italy in waters over 100 m deep.

The SDP is an adaptation of the submerged tension-legged platforms developed by the oil industry for offshore rigs. Using such structures for wind energy means that wind turbines can be positioned further offshore than is currently feasible, taking advantage of stronger, less turbulent winds.

Current commercially-available offshore wind technology requires the wind turbine foundations to be installed into the seabed on monopiles or jackets and the cost of installation grows as the depth of water increases. This means that potential offshore sites are limited to areas with a water depth of 50 m or less.

In January 2007 Blue H obtained the final authorisations to install its large scale prototype in the water 10 nautical miles off the coast of Puglia. It has also applied for consents to build a 90 MW wind energy park in the same area in waters 100-120 m in depth.

“Blue H intends to demonstrate that deepwater offshore windfarms can be built economically and certainly at a cost which is extremely competitive to the shallow water windfarms of today,” said Neal Bastick, Blue H CEO.

One of the advantages of SDP technology is that it reduces the weight of offshore units. According to Blue H, its future deep sea wind energy units will weigh less than 800 tons compared with around 2100 tons for a comparable shallow water offshore unit. Cost per kWh should also be reduced through the possibility of deploying larger turbines.