The Next Generation: A Comparison of the new Offshore Turbines

These new mega turbines are much bigger and have a higher capacity than turbines of the first offshore generation.

Let's start with one of the biggest companies producing offshore wind turbines: Siemens/Germany. The company has been building offshore turbines since 1991 and installed more than 2 GW so far. The world's biggest wind farm, London Array, is implemented with Siemens models solely. The best selling type at the moment is the SWT-6.0.154. The turbine has a capacity of 6 MW and a rotor diameter of 154m. Tower height can be adapted to the respective site. The model has been in use for some time now and is very reliable.

Despite record-breaking capacities the industry must reduce costs. Siemens developers constructed a turbine with 50% less moving parts inside the nacelle and thus reduced weight significantly. Result: Remarkable facilitation of transport and installation, less costs.

But competition is heating up the market as second Germany-based manufacturer REpower just introduced its new model 6.2M152 at the EWEA Offshore. This model is a further development of the successful 6.2M126 with a 26m bigger rotor diameter of 152m. As the name states the capacity is 6.2 MW and promises 20% more power with 9.5 m/s wind speed than the former model. Disadvantage compared to Siemens: The prototype is due for installation at the end of 2014 (onshore) while series production will not start until 2016. Although the company is merely ten years old, they have been dealing with turbines bigger than 5 MW since 2004.

But there are more countries to distribute mega turbines. During the fair French company Alstom announced the installation of the biggest offshore wind turbine of the world. They erected the second model (the prototype has been installed onshore) of the Haliade 150-6MW at Belgium offshore wind farm Belwind. The 6MW-turbine has a rotor diameter of 150m while the tower is at least 100m in height. Though the machine doesn't have all necessary certifications yet, the company plans to start serial production in the first half of 2014.

Alstom also brought down costs by reducing the parts inside the nacelle.

But Korean company Samsung went one step further already. They showed off their new 7MW-turbine in Frankfurt. The prototype has been erected offshore just some days ago in the Scottish 'Energy Fife Park'. The rotor diameter is a record-breaking 171,2m.

The company does have offshore working experience mainly through building vessels and working in the oil and gas industry. But for four years they have been building wind turbines investing 70 million pounds in the prototype. The company chose its erecting site in Scotland as the country has the needed infrastructure and is located in the middle of the booming market. Up to now Samsung had installed wind turbines in Korea, the US and Canada. Now they want to get involved in the European market.

Samsung's John Thomas Olsen commented on the new model: “We have built the biggest turbine with a life span of 25 years. It's actually not a turbine anymore, it's a power plant.”

The certification process will last until April or May next year, afterwards production will start.

Developers decided to use less parts making the turbine less expensive. Furthermore the installation process of most parts can be done onshore. “Try to replace some parts in the nacelle of an offshore wind turbine during a storm. That's not an easy job. But less parts means less maintenance. Anyway our focus is on best quality”, Olsen continued.

A small hint in the direction of fellow manufacturer Vestas from Denmark. Vestas is one of the offshore pioneers, but had to learn the hard way which nearly ended in bankruptcy. But now the company is back. Together with Japanese corporation Mitsubishi they announced a joint venture in summer forcing the construction of the world's first 8 MW turbine.

Vestas installed more than 55 GW in the last 30 years, more than 30% offshore. That makes more than 24.000 installed turbines. And they are not afraid to use paths less traveled: Most offshore wind turbines are just modifications of older onshore models. But the new 8MW-turbine is a whole new model designed especially for offshore use. The rotor diameter will be 164m which makes it the second largest after the Samsung blades. More details were not revealed at the show. News on this turbine are due later next year.

Same goes for the Chinese. Some of the companies recently discovered the offshore wind business, like Ming Yang. But as always: No details for the foreign press. Ming Yang didn't participate at the EWEA Offshore, but their partners, Germany's aerodyn, did. Their developers are also working on an 8MW-turbine, but the design is significantly different as there are only two blades. This again means a serious reduction of weight giving the developers the opportunity to build a helicopter landing platform on top of the nacelle instead.

But at the moment a prototype for this model doesn't even exist. Testing of the smaller 6.5MW-turbine is underway for 18 months in Chinese waters. But aerodyn let the world know that they didn't commit themselves to Ming Yang exclusively: With the tests being finished everybody will be able to buy a license for this turbine.

Meanwhile, Ming Yang is thinking even further: Three months ago the company revealed plans for a 12MW-turbine with just two blades.

This turbine would be revolutionary in many ways, but it also comes with a problem: Up to date vessels and cranes can only transport and erect turbines up to 8MW, experts say. So it is quite likely for the 8MW models to be the next generation in offshore wind turbines.

Another manufacturer, France-based Areva, announced a new offshore wind turbine coming soon. The capacity? 8 MW.