Tower Of Sun
By Eric Ellis, Chris KleesJuly 18, 2012
A futuristic solar power station in Andalucia aspires to be the model that can provide a cheap, clean and efficient solution to electrify the world.
I NOW know what consumed Richard Dreyfuss as he entered The Mothership at the end of Close Encounters of The Third Kind. Like the ethereal glows that are Spielberg's cinematic signature, the light emitting across southern Spain's arid plains from Abengoa Solar's soaring towers bewitch and entice much as it was in 'CE3K' for Dreyfuss; hypnotic, seductive and utterly irresistible.
Doo-dee-der-doo-dooooo! One can almost hear those five iconic notes from Close Encounters over the Andalucian cicadas, here in Europe's sunniest region. I'm drawn, like Dreyfuss, from kilometres away, compellingly closer to the facility's otherworldly towers as if engulfed by a subliminal magnetic field. A flat-topped butte suddenly rising from the sunflower fields here would not surprise. The scale of it, with those colossal rays, is spellbinding and even a bit spooky. It's impossible not to be beguiled by it all.
Abengoa claims this as the world's biggest commercial solar power station, situated 30 km to the west of Sevilla — and visible from almost as far away. Spain might be in dire economic crisis but this is a project its Spanish promoters believe is a model to power a warming world, as Abengoa rolls out identikits in joint ventures in similarly sunlit climes; the Middle East and North Africa, an Obama initiative in the American West and, they hope, Earth's poles and Australia too.
The two main towers rise 110 metres and 160 metres from the plain. The tallest — PS20 — is Spain's seventh tallest building, around 20m higher than the highest point of the Sydney Harbour Bridge, about the same height as a conventional 40-storey skyscraper. What looks from afar like cables suspending from a huge bridge are actually powerful sunbeams illuminating the everyday dust and haze of the parched Spanish campo. That's the beginning and the end of the pollution around here, little of it generated by the plant.
At the summits of the towers are what seem like intense "second suns", huge bowls of concentrated light that are impossible to view longer than a few seconds with the naked eye. These pits capture and process the concentrated reflections of around 2000 solar panels, known as heliostats, arrayed on the ground below in neat radial lines across an area roughly equal to the playing surface area of the Melbourne Cricket Ground.
These mirrored panels — cool to touch but generating heat approaching 250 degrees Celsius — reflect into the towers barely 100 metres above. Each panel covers about 120 square metres, or the side of a conventional suburban house. Though the heat they channel to the towers is extreme — one victim of the plants' presence are birds straying near the sun bowls — one can stand on the tower roof just a few metres above the bowls in comfort.
Operated electronically from a control room, the heliostat fields are constantly (though imperceptibly to the human eye) moving, each tracking the daily arc of a sun that shines for about 16 hours during the Andalucian high summer.
It seems odd to hear the eight-year-old complex described as a plant, for there is relatively little about the facility that could be deemed conventionally industrial. The few employees work mostly in maintenance and the high-tech control room, and there's little actual infrastructure apart from the concrete towers, the solar panels and the compact power distribution stations they feed, sending power on to Spain's national grid. And it is spartanly clean; no mines, no smokestacks save for steam and no significant pollution. Moreover, the sun's rays are free and, around here, pretty much infinite all year round.
As for plant, the word is perhaps best reserved for what inspires the Abengoa technology, those ubiquitous sunflowers that punctuate large parts of Andalucia, and surround this facility.
They are known in Spanish as girasoles, which translates as "turn to the sun", and which is precisely what the Abengoa Solar group would like the world's electricity consumers to do.