Bigger and Taller
Many turbine manufacturers are focusing on increasing capacity by developing bigger turbines. Vestas, for instance, is working on its V164-8.0MW. Recently the company’s test bench at its global testing centre in Aarhus, Denmark, has started operation. The 20MW test bench is capable of testing the full nacelle of the V164-8.0MW, validating the performance, robustness and reliability of the turbine over a simulated 25-year lifetime. Samsung is developing its 7MW turbine, and the prototype 7MW offshore wind turbine has been delivered to Narec’s new test facilities in Blyth, Northumberland, UK. Initially, Samsung’s nacelle will be used to commission Narec’s independent 15MW capacity test facility, before a six-month testing programme begins on the nacelle. Furthermore, Gamesa recently installed its first offshore wind turbine with 5MW of nominal power at the Arinaga Quay in Gran Canaria (Canary Islands). These are just a few examples and other manufacturers are working on bigger turbines as well.
Bigger turbines also mean taller towers and these taller towers have implications in terms of both safety and sustainability. With taller towers it is particularly important that technicians are able to work safely at these heights. For instance, a tool dropped from an elevated work platform poses immediate danger to personnel and equipment below. While there are federally mandated guidelines in the USA for securing people working on surfaces 4 feet (1.22 metres) or more from the ground, there are no such requirements for securing tools. In his article on page 6, John Martell discusses why organisations need to implement some type of tethered tool programme in the interests of safety, and how new technologies are making it easier for technicians to use tethered tools.
The environmental impact of taller towers can vary significantly. Sarah Gustitus, an environmental engineering student at the University of Florida, takes a deeper look at four options for taller towers. Steel towers, concrete towers, hybrid towers and the recently developed ultra high performance concrete (UHPC) tower are all viable options for hosting 100-metre (328-ft) hub height turbines. In her article on page 29, a life-cycle analysis (LCA) is used to compare these tower options over both short-term and long-term periods to reveal the most sustainable tower option for these taller turbines.
It is not only the traditional manufacturers who are working on turbines with a higher capacity. In our March issue 2013 we published an article from SheerWind about its Invelox wind technology. Now SheerWind has created its next generation of mega wind producing technology, without the mega size. The company’s patented Invelox system offers power capacity of 25MW. By concentrating and accelerating wind, it creates a similar effect to the natural wind corridors used by traditional wind towers. Invelox technology has been reviewed and validated by a technical advisory board consisting of a team of experts from research universities and agencies. Prototypes were tested under controlled laboratory conditions, and test results were used to build and validate full-scale computational fluid dynamic models. Field data collected to date has validated results. According to the company the technology requires no subsidies, is price competitive with traditional energy, and has far less environmental impact than turbine-topped towers.
Enjoy reading,
Floris Siteur
Publisher