In the bone-dry plains outside the Spanish city of Seville, stands a 40-storey concrete tower that locals say emits an eerie daytime glow, or "iluminación". Could it be a new age shrine of some sort, a pilgrimage spot for the local Catholics?
Nope. It's Europe's first commercially operating power station fuelled entirely by the sun's rays. Environmentalists hope the tower will become a model for clean energy, powering Southern Europe's more arid regions without pumping harmful greenhouse gases into the atmosphere.
Built by Spanish energy company Solucar, the tower is said to generate 11 Megawatts of electricity – enough to power 6,000 homes – without emitting a single whiff of harmful pollutants. Solucar says the plan is to expand the plant capacity to power as much as 600,000 homes – equivalent to the population of Seville.
The persistent fuzzy white aura enveloping the structure is generated by reflected light beams bounced off a field of mirrors surrounding the tower. There are plans to build four arrays of mirrors (the first was completed this month); each array will contain 600 mirrors. The mirrors rotate to follow the sun along its daytime arc.
Here's how it works: The sun's rays are captured by the mirrors and re-directed at a heat exchanger at the top of the tower. The exchanger converts the solar energy into steam, which, in turn, turns a set of turbines that generates the power. The tower collects enough heat during the day to go on producing energy for a period of one hour after the sun sets. Once the additional mirrors are in place, that period will grow longer, Solucar engineers say.
By 2020, Spain, Italy and Greece, for example, could produce enough solar energy to power 26 million homes in that region
The promise of the Solucar plant has the energy experts buzzing. Similar plants are being discussed near the desert cities of the American Southwest, Australia and the Middle East. And, Spain is not done either.
Earlier this week, Israeli-Spanish thermo-solar power station developer Ener-T Global Ltd. and Spanish renewable energy company Grupo Enhol announced plans to jointly build two 50-megawatt thermo-solar power stations in Spain for about $809 million. The plants, which would produce nearly five times the energy capacity of Solucar's structure today, are planned for the Extremadura province in southwest Spain. The first of which would come on line in 2009, the companies said.
Long regarded as a quaint, but inefficient energy source, solar or photovoltaic power is now considered one of the most promising alternative energy sectors. As investments rise into the tens of billions of dollars, there are bullish forecasts for the world's solar power consumption. By 2020, Spain, Italy and Greece, for example, could produce enough solar energy to power 26 million homes in that region, according to the European Photovoltaic Industry Association. And, in 2007 the global photovoltaic industry is expected to invest 2.6 billion euros in new production capacities.
The boom in solar power stations could benefit those in less sunnier climes, experts say. By cabling the power to far-away markets it would make desolate locations – think Africa's Sahara desert region or even the North or South Pole (during their perpetually sunny periods) – viable clean energy producers for the rest of the world.
At the moment it may cost three times as much to generate the equivalent power via oil or coal, but solar energy production costs are expected to fall as technologies improve. And, of course, unlike fossil fuels, there is an unlimited supply of solar power. Plus, the environmental impact is nil – unless, you consider a massive concrete tower in a field a blight on the landscape.Bernhard Warner is a technology reporter based in Rome. He is the former European Internet Correspondent for Reuters and, prior to that was a senior editor at The Industry Standard. His work has appeared in Wired, The Times Online, Time and The Guardian, to name a few. He also works as a Web 2.0 consultant for Custom Communication