Dubai conjures up BIG images; not just the tallest structures, although it currently holds that crown, but also big as in flamboyant, lavish and generally larger than life. Amidst the opulence, extravagance and seemingly limitless budgets – or perhaps because of the latter – Dubai is increasingly embracing its green side. The latest building designed for the city to cross our desk has a foot squarely in both camps - the Almeisan Tower combines a delicate, soaring structure with a 600kW solar tower and passive cooling systems claimed to be almost "triple zero", which means it has zero emissions, zero energy requirements and zero waste.
Sadly, the tower may never see the light of day. It was submitted by architect Robert Ferry in a recent competition to design a tall emblem structure for Za’abeel Park in Dubai, but theå entry was unsuccessful.
The 165 meter Almeisan Tower (Almeisan is the Arabic name for one of the brightest stars in the sky, located in the constellation Gemini; its name derives from Al Maisan, or “the shining one”) would generate both its own energy and the energy required to run the rest of Za’abeel Park, by means of a 600kW solar power tower. A staggering 224 large heliostatic polished mirrors track the sun and reflect a concentrated beam of light into a central collector where a furnace containing liquid sodium is heated to a constant 500 degrees Celsius, and in turn powers a steam turbine.
The building is designed with eight main concrete structural piers which are angled almost to touch at 50 meters above the ground. They are tied together with a tension ring before blooming outward like the bud of a flower and opening up to reveal the inner piers that support the café and structure of the collector tower many meters above.
The podium, above the parking level, features conference facilities, a children's library and cultural center and is surrounded on three sides by floor to ceiling glass curtain walls. Eight wind piers passively cool the area by drawing the hot air to openings 110 meters above the ground, where the winds and cooler air create a chimney effect. The plants and soil bed that make up the living walls and roof of the podium level provide further passive cooling by absorbing energy and acting as a heat sink for modulating the temperature variations in a similar way to mud walls in traditional indigenous huts.
Four glass-walled elevators carry visitors up and through the green roof towards the observation platform and café levels, giving a panoramic view of the park below, the dynamic nature of the converging and diverging structural piers, and the mirrors.
The observation platform at 100 meters provides stunning views of the city on all sides as well as the large mirrors, which are mounted at the same level as the visitor’s feet and shine converging beams of light through which to gaze out into the distance. The beams of light created by the mirrors would be visible from a great distance... and we suspect might not be that popular with airline pilots.
The café occupies the two floors above the Observation Platform. A pearl-like enclosure enveloped by secondary structural piers, it provides views of the city withbeams of light tenting above visitors from all directions. The secondary piers stem out from the primary piers some 60 meters below and gently curve upward, meeting above the café to provide support for the base of the collector tower.
Wind towers have long been used in the region to cool buildings and Robert Ferry's Almeisan Tower has been designed to use this ancient technology for a large-scale, modern application. The UAE 's emerging environmental credentials are spurred on by excessively long, hot summers and minimal rainfall. Gatherings such as the Green Dubai World Forum 2008 which focused on sustainability and environmental problems and possible solutions may signal the way forward. Perhaps in the not-too-distant future we'll see developers in Dubai vying not only to build the tallest or the most luxurious buildings but also the greenest.