Sunday, August 24, 2008
As reported by SciDev.net earlier this month, Namibia may soon construct its own solar updraft tower outside its capital city. This renewable-energy power plant isn't going to be a prototype to test the technology's engineering and economic feasibility; rather, it is proposed to be an actual working plant plugged-in directly to the country's electrical grid.
Not to be confused with a solar power tower, to which sunlight is focused by mirrors arrayed at its base, this one produces energy by “heating air inside a vast transparent tent, several kilometres in diameter, at the base of the tower. This hot air rises inside a tall concrete chimney, driving wind turbines linked to generators. The tent can also be used to grow crops.”
We should state that questions of its feasibility don't so much interest us as the image of hundreds of these Apollonian axis mundi dotting the desert, puncturing both sky and land.
It may be one and a half kilometres high and 280 metres wide, but is that enough to meet the desired energy output?
Will its power be as cheap as coal power?
Can Namibia and its partners afford the $900 million price tag?
Somehow contemplating these and other issues can't be as fascinating as imagining an arid rainforest of solar towers mechanically evapotranspirating in the Kalahari, divining the surrounding air into static mini-hurricanes, their whirring blades immitating the mating rituals of imagined fauna. No one will doubt that this new landscape is as much a natural part of the country's ecology as the boabab tree. In fact, so vast is it that it may be considered a new terrestrial biome and given its own Köppen classification.
Give them a geometrically interesting facade, and everyone will want to cultivate their own rainforest, with the enthusiasm never given to wind farms.
Meanwhile, The New York Times will have to rewrite their recent Namibian travelogue to include this “dazzling geological display” and “otherworldy landscape.”