Harnessing the wind

zoom

Bahrain World Trade Center. View from the podium.

zoom

Shaun Killa’s initial sketch of the BWTC concept.

zoom

BWTC under construction.

In October 2003, the Dubai office of leading architectural firm, Atkins and its principal architect and head of design, Shaun Killa, was approached by a client in Bahrain and asked to design a building that would be unmatched anywhere else in the world. Upon arrival in Bahrain, they found the site had an existing shopping mall, a hotel and a small office building. The client's brief was to increase the commercial office space considerably, double the size of the shopping centre and increase the parking facilities by incorporating a multi-storey car park into the design. It was asked to preserve the existing buildings and incorporate them into the new development to create a seamless division between the ‘old' and the ‘new'. On the day it visited the site, for what would become the Bahrain World Trade Center (BWTC), it was an unexpectedly windy day and Shaun Killa couldn't help but think about sailing.

Concept design

After the requisite photos were taken, details jotted and questions answered, Killa recognised the wind velocity, and more importantly, its direction, with respect to the shoreline site in Manama. He began thinking that his years of research into harnessing wind energy into building designs, could actually become a reality. "I had been researching the integration of wind turbines into buildings for more than two years before going to Bahrain," says Killa. "In 2002, I had considered a project in Dubai where wind turbines were incorporated and although the project didn't materialise, it started to intrigue me, leading me to continue my research into understanding wind turbine constraints."

Although the seed had sprouted in Killa's mind, there were more pressing issues to be dealt with before he would allow himself to consider integrating horizontal-axis wind turbines on to a building. In fact, it wasn't until Killa and colleagues began masterplanning the site and began extending the axis of the existing shopping centre toward the shore, did they realise that the site actually lent itself to a twin-tower development. "As soon as we recognised the axial relationship, I started thinking more about the wind aspects in Bahrain," says Killa. "I reviewed Bahrain's wind rose and found that approximately 70% of the prevailing wind was coming directly off the sea onto the site, which was perpendicular to where the turbines would be, and would create a perfect wind regime for turbines between the buildings."

The challenges

Having spent a significant amount of time researching this type of integration, Killa knew he had to work with the industry standard, certified horizontal-axis turbines which are generally supported on masts in the ocean or on a greenfield site. He was also well aware of the very lengthy research and development process-often five years or more-of testing a non-standard wind turbine to get it to where it can attain the requisite certification.

Although some designers have attempted to use large scale, non-standard vertical-axis turbines, their projects had not materialised. "The research and development work to certify non-standard turbines would take years and cost a fortune," says Killa. "So it's better to consider standard certified wind turbines and find willing manufacturers."

After contacting as many as 30 manufacturers worldwide, Killa found that many of them were uninterested in what they considered to be a small scale project. They were used to turbine installations that included 90m diametre turbines, generating three to five megawatts and installations of between 10 and 100 turbines. According to Killa, many of the manufacturers didn't see the advantage of being involved in a project that included three 29m diametre turbines supported on the bridges of a twin-tower development-regardless of its potentially groundbreaking nature. After months of communication, they found a design-and-build manufacturer in Norway to install the turbines.

The final challenge was one of economics. Where other projects had failed to properly consider the influence of wind direction and velocity of the location, and a design that created a perfect shape for wind turbines, the costs of integrating turbines into the development rendered it economically unfeasible. To address this problem, Killa and his team devised an unusual concept. "The way to keep costs down was to create separate towers, which by themselves would be efficient, however shaped and orientated to harness the wind and then literally bridge the two structures. This method made installing the turbines relatively inexpensive" says Killa.

"We had to conduct a feasibility study to check the economic and technical viability of this world-first integration. Very early in the study, it became clear that it was perfectly possible to have turbines between the towers because of their shape and they would comprise around 3.5% of the cost of the development," adds Killa.

Print | Email | Discuss this article |

USER COMMENTS (0 COMMENTS)

POST A COMMENT

CLICK HERE TO POST A COMMENT

Add your Comment All posts are sent to the administrator for review and are published only after approval. ArabianBusiness.com reserves the right to remove any comment at any time for any reason. Please keep your responses appropriate and on topic.
Name *
Remember me on this computer
Email *	(Your email address will not be published)
City
Country
Subject *
Comment *
Notify me of further comments
Security Code *
Please click post only once - your comment will not be published immediately.