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.

Wednesday, 10 October 2012

Vertical Farming: The Rise of Food Sustainability

You may or may not have heard about a new type of farming called “vertical farming”; yes, it’s exactly what it sounds like! Vertical farmers utilize unique space by farming upwards, in and on top of skyscrapers and tall buildings. Vertical farming is a great way towards a more sustainable alternative to regular crop farming because it means you can buy locally grown food while not using up any land. This can reduce emissions created from food products that travel long distances and, with an abundance of buildings, it’s possible to have hundreds of thousands pounds of vegetables and herbs produced annually and sold locally!

Dickson Despommier, a professor at Columbia University, describes here why vertical farming could, and should, change the world: 

(Learn more at verticalfarm.com

With Vancouver vying to be one of the greenest cities in the world by 2020, vertical farming can be one of those ideas that really puts a city over the top. Enter Alterrus Systems Inc., a Vancouver based company that was formed for the very purpose of creating North America’s first ever “VertiCrop” farm. VertiCrop is a technological innovation that revolutionized farming by allowing vegetables and herbs to grow vertically without any soil, pesticides, or herbicides. VertiCrop can change the way we farm by providing fresh produce to local communities quicker than ever before. The first-ever VertiCrop farm in North America will be located on the roof of a parking lot located in downtown Vancouver and will produce around 150,000 pounds of green produce annually. The food will then packaged and sold locally under the brand name “Local Garden”.

A Problem of Sustainability
The world’s population is increasing. But we are running out of land for farming. 70% of all fresh water on the planet is used for agriculture. yet the runoff is unusable due to contaminants in the soil. To sustainably create the amount of food the world will require, farming needs to be modified. We require a combination of solutions and a paradigm shift in how we grow and distribute healthy food.
The World Needs to Grow Up
Vertical farming addresses the problems of increased demand for sustainable, nutritious food. Vast areas of underutilized urban space, such as empty buildings and rooftops, can be used to grow fresh produce at or near to where it is to be consumed. Contrast this with the status quo that ships produce to grocers from an average of 1,500 miles away. Transporting produce over such long distances not only generates carbon emissions, but a dependence on foreign oil. In addition, closed-loop vertical farming environments don’t require the use of harmful pesticides and herbicides, which totally eliminates contaminated runoff. And with only the minimal amount of water needed to grow a variety of fresh, healthy produce, this sustainable farming method helps conserve our planet’s most precious resource.
- Alterrus

In the United Kingdom, the team at Vertical Veg are teaching people how to grow vertical farms themselves, right on their balconies! By following their blog or attending classes, individuals can learn how to grow food to feed themselves, their families, and more. Depending how much space each person has, they can grow as little as a one plant to as much as the creators themselves! Vertical Veg reports how much they grow by weight and dollar value so readers can really see the difference this sustainable innovation can make. Check out their Growing Diaries to learn more.

If you're interested in growing your own food try searching local information to ensure you grow the proper crops at the appropriate times of year for the greatest success. Be sure to review your building and city bylaws as well to ensure you are operating within your limits! There are also many other sustainable agricultural projects popping up around the world so if you're interested in participating be sure to keep an eye out. In Vancouver the Strathcona Community Gardens and SOLEfood Farm are doing their part to support the greenest city. Restaurants such as the Forage are also going green by using local foods, emitting zero-waste, and installing solar panels. There are also food trucks that are being set up that sell food products made from local ingredients and utilize renewable energy.