4 ms·
This is ridiculous. The designer, David Fisher, makes more detailed claims here: http://www.dynamicarchitecture.net/dubai-project.htm http://www.dynamicarchite
by pingswept 18y ago
This is ridiculous.
The designer, David Fisher, makes more detailed claims here: http://www.dynamicarchitecture.net/dubai-project.htm http://www.dynamicarchitecture.net/dubai-project.htm
Judging by the drawings of his tower (http://www.dynamicarchitecture.net/schema/schema_big.htm http://www.dynamicarchitecture.net/schema/schema_big.htm), it's about 300 x 50 m. Ignoring the narrowing of the tower as it rises, roughly 20% of the area is devoted to wind turbines. That's around 15000 x 0.2 = 3000 m^2.
He claims that the average wind speed in Dubai is 16 km/h, or 4.4 m/s.
Assuming a Rayleigh distribution for the wind speed, the average power available as kinetic energy in the wind is (6/pi) * 0.5 * (density of air) * area * (average velocity)^3.
The density of air is 1.2 kg/m^3.
That's (6/3.14) * 0.5 * 1.2 * 3000 * (4.4^3) = 290 kW. If the wind turbines were 30% efficient, which would be pretty good for a vertical axis turbine stuck in a building, the yield would be 100 kW.
This ignores the narrowing of the building, the lack of wind near the ground, and obstruction from other buildings.
The building has around 50 m * 50 m * 60 floors = 150000 m^2 of floor space, so the areal power density is about 0.67 W/m^2.
To meet the claims of a 10x ratio between energy generated and used, the building can budget 67 mW/m^2. That might be enough to light a single LED in each room.
Oh, and the average temperature in Dubai is 27 C. I guess they can run the air conditioning when all the LEDs are off.
- michaelneale 18y agoExcellent and humorous analysis. Thanks !
- pingswept 18y agoNo, thank you, my good man. As I've been thinking about it more, the most disturbing part of the tower design is not the low energy yield. It's far more alarming that this gets picked up as an exciting direction for development (judging by the discussion of the tower on TreeHugger, Inhabitat, and similar sites). I desperately want us to figure out how to capture energy from renewable sources in an economically viable manner. If we don't do that, we are royally screwed. However, the central problem is not, for example, that we have no land for wind turbines or solar panels. The core problem is low power density. We need to be putting up the most efficient, cheapest turbines we can build in the windiest areas, not less efficient turbines in a not very windy area with the added costs of building integration. It's not a good idea that won't quite work-- it's a terrible idea that's headed in the wrong direction. It's morons like David Fisher (the designer) who give conservatives a reason to say "Bah, that renewable energy stuff is a load of crap."
- michaelneale 18y agoI agree. What we have with energy is a supply side problem. Yet all the thought energy of the public is directed toward the demand side (either reducing/conserving things, or changing the sourse). Yet if we were to solve the supply side in a sustainable manner, we would solve a whole lot of other things very very quickly.
- michaelneale 18y agoSourse? What the heck was I thinking ;)