Bahrain World Trade Center

The Bahrain World Trade Center, BWTC short, is a building in Bahrain's capital Manama. It consists of two main towers are interconnected by three cross-members. Each of the two sail-shaped building reaches a height of 240 meters with 50 storeys ( including 34 for offices). Under the building is a shopping hall. A special feature of the skyscraper are three mounted on the crossbars wind turbines, so is the Bahrain WTC world's first skyscraper with integrated wind turbine. It is part of the World Trade Centers Association. The construction of another, but completely energy self-sufficient skyscraper in Bahrain - the 322 meter high Burj al - Taqa - is planned.

Location

Comprised of two connected by three bridges not walk towers, the building is close to the Persian Gulf. It is named after the Bahrain Financial Harbour ( 260 meters, 54 floors) the second tallest building in Bahrain. It is removed after official figures, 15 -minute drive from Bahrain International Airport.

Building and history

Construction on the Bahrain World Trade Center began planning in August 2004 after three years. After six months, already focused on the first five floors, after two years of construction, the final height of 240 meters was reached. After the third cross brace was hoisted and mounted. After this action, the generators were attached to the cross braces, and then the rotors are assembled on the ground, transported to the top, and also mounted. On 19 March 2007, the first, lowest wind turbine has been installed, then the middle and the top. Then could the crane to lift the wind turbines and cross bracing, which was mounted between the two halves of the building, to be dismantled. On 11 September 2007, all 50 floors were completed. Since August 8, 2008, the first, lowest wind turbine provides electricity, the average was followed a month later, the top one more later.

The National Commercial Bank of Saudi Arabia announced in July 2006 that it intends to move its main office in the Bahrain World Trade Center.

Building integrated wind turbines

Technical data of the wind turbine

A special feature are integrated into the building three wind turbines. Should be covered by wind energy between 11 to 15 percent of the cost of the energy consumption, since each of the wind turbines each with up to 46,000 watts of electrical power supplies. The entire system - so all three wind turbines - delivers so in 1.2 GWh. The attached at three cross braces between the towers of wind turbines have a diameter of 29 meters each. Make it the world's first building-integrated wind turbine power plant dar. The diameter counteract the distance 34 meters between the two towers. While the distance between the two skyscrapers is at the front of the building complex still 126 meters, it measures at the end of the building only 33 meters. At full capacity, originating from Denmark rotors reach a speed of 38 revolutions per minute. Each system weighs 11 tonnes, with 6.5 tonnes for the generator. The highest wind power plant is located at an altitude of 133 meters.

Aerodynamics and efficiency of wind turbines

Critics point out, however, that the rigid stationary propeller against vortex, must arrive updrafts and downdrafts and can not rotate in the wind direction, making the current yield would be lower than planned. But the attempt has been made to counteract. The double building is intended to act as a Windkonzentrator. The shape and arrangement of the two towers is important. Your bases are oval, beyond the two halves of the building are not parallel but are funnel-shaped arranged so that the distance between the two halves of the building between 126 meters and 33 meters varied. At the end of this " funnel " the three bridges are attached with the wind turbines. The oval shape that mimics the profile of aircraft wings, and the funnel-shaped arrangement of the towers ensure that wind from the side meets as possible at right angles to the wind turbines. Since then, engineers have demonstrated through computer simulations and tests in wind tunnels that could also come from an angle of 75 degrees by the special sail-like form of the separate towers of the wind, so to turn the turbines.

Since wind speeds are higher at high altitude and thus the top turbines would be faster vulnerable to damage, the building tapers upward, so that the wind is up less focused on wind turbines as the bottom.

Security

Since rotating parts do not necessarily reflect the safety support to a building of that special measures have been taken here, so that the building withstands wind speeds up to 250 km / h without damage. The rotating tips of each rotor blade to ensure that in such wind turbines not hazardous. At high wind speeds, they can be tilted so that they offer the low wind resistance surface. If there should disconnect a rotor blade of the wind turbine once, keep it steel cables that are attached to the inside of the wind turbines, from getting to endanger one of the two office towers or shopping center located below the wind turbines.

In order not to damage the rest of the system, the rotors are normally mounted on a tower with a nacelle and the rotor blades are not parallel to the tower, but are tilted about five degrees, so that a larger distance between the rotor blade tip and tower can be achieved. At the Bahrain World Trade Center, this technique can not be used because two struts out of the turbine. Therefore, we decided to use a positive sweep of the cross bracing. At the end tips of the "V " s, the wind turbines are then attached, so that between the rotor blade tip and cross bracing, a distance of 1.7 meters was achieved.

Another problem is that the building fluctuate at high wind speeds. Hard links between the two towers could then lead to tensions. To prevent this, it was decided to mount the cross braces on only one side fixed, on the other hand, it is only on steel wheels - thus movable - attached to the other building.

More

However, the building will be climate-friendly not only by the wind turbines. It also has double-glazed windows that reflect up to 85 percent of the heat rays coming from the outside, and claim as the air conditioning less. The lighting and the air conditioning should be particularly efficient beyond.

Film

• The Power Tower in Bahrain documentary, 46 min Production: N24, first broadcast 8 July 2009 Summary and Video Stream of N24