“With this test, it will confirm in an accelerated way the performance of the tower in operation. This will improve the reliability of the structure and minimise any technical risks before the first pre-series,” said Ion Arocena, Head of the NBTECH Tower Program.
This will be achieved by using a novel system that generates loads on the upper part of the tower, by oscillating it in a controlled manner, to simulate real life conditions in a short time frame.
This test method, never performed to date on a wind turbine tower, was formulated during the NEVA project. The project is a collaboration with the National Renewable Energy Center of Spain and financed using FEDER funding from the Spanish Ministry of Economy, Industry and Competitiveness.
The new structure with its self-erecting system, which doesn’t require the use of large cranes, will enable the tower to reach heights of up to 200m in the coming years.
However, to be in line with the current market situation, NBTECH has set the height of its prototype to 160m. Despite this, it will still be the tallest wind turbine tower installed outside of Germany.
Therefore, the hub height of the prototype tower designed by NBTECH will be 160m in total. It is made up of two segments: an 86m high frame structure of three columns designed and patented by NBTECH; and a 71m high conventional tower placed on top.
The main innovative feature of the Nabralift (commercial name for the structure designed by NBTECH) lies in its patented assembly system, a new self-erecting process using hydraulic jacks on the ground. This allows for the tower to be elevated by introducing new modules from below. The tower is composed of smaller elements, which eliminates the need for specialized trucks and cranes. This new system signifies huge advances for the logistics of transport and assembly of the tower.
The company has also developed technical solutions for wind turbine blades under the name of Nabrajoint.
“Basically, it consists of a novel joint for a modular blade that will facilitate the transport of large wind turbine blades in two or more sections,” said Javier Callén, Head of the NBTECH Modular Blade Program.
The Nabralift technology solution offers a significant cost saving compared to conventional towers of up to 15-20 percent (depending on the height and power output of the wind turbine): firstly, due to the simplicity of transport and logistics as there is no need for specialized lorries or cranes; secondly, due to its construction being 20 percent lighter than a conventional tower of the same height; lastly, because it is installed on a foundation of three concrete pads, which reduces the consumption of concrete by 30-40 percent compared to current towers.
NBTECH has designed each part of the tower using conventional manufacturing technologies, straightforward to deploy in any continent, with maximum reliability and low costs.
In the last months NBTECH has closed various agreements to manufacture its tower and blade components to be supplied within Europe, with the objective to deliver the first pre-series in 2019. Deployment in APAC and LATAM is expected soon due to the high level of interest shown by potential clients.
For information: Nabrawind
