Tuesday, 30 October 2012

Solar Power for a Sustainable City

Imagine a city where all electrical energy is from clean, renewable resources.  Does this sound like an implausible idea?  Well, this vision of the future is already in existence today and in one of the most famous cities in the world – Seville, Spain!  Seville is the fourth largest city in Spain and has been in the global eye for millennia.  It is where Ferdinand Magellan began the first voyage around the world and where the famous opera Barber of Seville calls home.  However, what makes it remarkable today is that it is almost entirely powered by solar energy!

How It Works

Seville gets over 3,000 hours of sunlight each year, which makes it a perfect place for solar energy.  The process works by focusing large mirrors called heliostats on a receiver which heats water into steam as it travels into a drum.  This is used to propel massive turbines creating electrical energy before being condensed back into water and beginning the trip all over again.

A solar tower power plant

The Solucar Complex

The Solucar Complex is where Seville will get all of its energy needs from.  It uses a wide range of technologies including solar towers and troughs.  As newer technologies are discovered, they have been incorporated into each new plant within the complex.  Its construction began in 2004 and the first tower, the PS10, began operations in 2007.


While the current Solucar Complex generates 180 megawatts (MW) of power, it has been a process to get there.  In addition, the total scope of the complex is only halfway built!  By the end of completion, it will have the capacity to generate power all of Seville, a city at almost 750,000 people.

The PS10 Solar Power Plant was the first completed portion of the complex, finished in 2007.  Capable of generating 11 MW or approximately 3% of Seville’s power needs.  This plant consists of 624 mirrors that heat water in a central unit and is the world’s first commercial solar tower. 

However, this was nowhere near enough for true power independence and a progression toward renewable sources.  The PS20 Solar Power Plant was added in 2009, capable of 20 MW.  It has double the number of mirrors and represents the 2nd generation of solar technology which means that the energy conversion rate is higher as well.  It is the most powerful solar tower in the world.

The PS10 and PS20 towers
Combined, these towers account for 10% of Seville’s power requirements.  As of 2010, the construction of Solnova 1, 3, and 4 have massively boosted the complex’s capacity.  These are trough style parabolic mirrors that track the sun as it moves across the daytime sky.  Each of the three plants generates 50 MW, boosting the total capacity of the current complex to 180 MW or 60% of Seville’s power needs.


There are still three more plants that are set to be completed in 2013.  There is the AZ20, a solar tower similar to the PS20 that will generate 20 MW of power.  There are also the Solova 2 and 5 trough plants, each with another 50 MW like their predecessors.  In all, this brings the total to Seville’s required 300 MW of power, all from solar energy!

The Solnova plants in front of the PS10 and PS20 towers

The Solucar Complex is responsible for the creation of 1,000 jobs in construction and another 300 in operating the various plants.  It is estimated that over the course of the complex’s 25 year life expectancy, it will prevent 600,000 tonnes of carbon dioxide from entering the atmosphere per year.  This amount of carbon dioxide reduction would be similar to the amount that could be processed by almost 1.5 million trees!

Abengoa Solar

Abengoa Solar have been involved in the construction and operation of the Solucar Complex since its inception.  They operate a total of five complexes throughout Spain and one in Algeria.  They are involved in the expansion of these current complexes as well as new projects in the United States and United Arab Emirates.  They are also involved in complex operations in Chile and Mexico as joint projects with other companies.

The Green Revolution

Many other cities all over the world are joining the revolution to attain their energy needs from 100% renewable, non-polluting resources and it doesn’t just stop at solar.  Wind, hydro, and other energy alternatives are constantly being researched and improved to increase energy conversion rates and to make it affordable.  This is also the plan followed by new urban planners for new cities and growth. 

What makes Seville so unique is that they are actively building infrastructure for their city rather than buying offsets from other areas.  Essentially, their power grid is unique for their citizens.  As the sustainable movement continues to evolve, so too will new ideas on how to make it possible.