February 22, 2012 — Wind energy is the most mature technology among all renewable energy solutions, according to Frost & Sullivan. Finding appropriate sites for developing onshore wind farms might, however, soon pose a challenge due to dense urbanization (especially in western Europe) and concerns about the negative visual impact that wind farms could have on the surrounding environment. This is creating a promising window of opportunity for the offshore wind power industry.
New analysis from Frost & Sullivan's Technology Developments in Offshore Wind Industry: Technology Market Penetration and Roadmapping research finds that the increasing interest in offshore wind power is driving the development of new technologies. The most important of them is the foundation for offshore wind turbines that sometimes represent as much as 40 percent of the investment costs.
"Another technological trend is the scaling up of turbine capacity and the use of synchronous direct drive generators, instead of asynchronous alternatives that require the use of gearboxes," said Technical Insights Research Analyst Tomasz Kaminski. "Gearless wind turbines offer enhanced reliability-an important factor in offshore projects where maintenance work represents significant costs."
Another technology connected to offshore wind farms is submarine cabling. Currently, energy generated by offshore wind turbines is transmitted to the mainland through the use of high voltage alternating current (HVAC) cables.
"However, as wind farms move further offshore, HVAC cables are becoming less economically attractive due to increasing transmission losses," said Kaminski. "Due to this, attention is being focused on high voltage direct current (HVDC) submarine cables."
The future of the offshore wind industry will depend on novel developments in foundation solutions for water 30 to 60 meters deep over the medium-term and, deeper than 60 meters over the long-term.
The most attractive alternative for widely used mono piles currently are jacket foundations that can be used in water between 30 and 60 meters deep. For the longer term and far offshore wind projects, the most probable solution appears to be floating foundations.
"Frost & Sullivan research shows that the jacket foundation is in an 'almost commercial' phase of development, while the floating foundation still requires a few more years of research," adds Kaminski. "Currently, only one prototype of wind turbine carried by floating foundation is in operation."
Besides problems connected with technology scaling up and the development of new foundation types, the transportation of wind farm components is another important challenge. Currently, there are very few vessels and cranes that can carry and install large offshore wind turbines.
Most marine transport equipment was designed for the offshore oil and gas industry, limiting their use in the wind industry. However, companies providing offshore construction services are looking to resolve this issue. The problem of shortages in specialized vessels should be addressed by the end of 2012.
"To boost offshore wind technology, developers should focus on lowering foundation costs," advises Kaminski. "Turbine operation costs can be decreased by introducing direct drive, gearless generators that are more reliable than asynchronous generators."
Revenue of offshore wind farm operators can be increased by technology scaling up and the introduction of 10 MW wind turbines. Bigger turbines mean higher energy generation.