In my last blog post I talked about how we can define sustainability, and the broader implications of “going green” that often go unexplored.  As I stressed in that post, devising new, more efficient means of energy generation is important, but far from the only way to achieve a level of true global sustainability.  The recent tragedy in Japan and ongoing nuclear crisis has shed a new light on the importance of safe and dependable energy sources.  Nuclear power is widely held to be an important means of power production – just ask France: Nearly 80% of their power is generated in nuclear power plants (Enerpub 2007) (Figure 1b).

I’ll be the first to concede that I am not enough of an expert on nuclear power to say whether or not we should be using it; however, there is no doubt that the meltdown in Japan will stir up lots of feelings on the subject (See Hank Green’s video for a superb explanation of nuclear power and the situation in Japan).  The Japanese nuclear tragedy will certainly cause the world to turn its eyes to new forms of renewable energy – means that will allow us to simultaneously cut our dependence on fossil fuels while providing a safer and more environmentally friendly form of power than most of the ones we currently rely on.  Making this paradigm shift will be no easy or expeditious task; a glance at the graphs below showing America’s and France’s sources of energy reveals the embarrassingly small amount that we currently derive from renewables (Figure 1).

 

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Figure 1: Power Sources in the USA and France

 

The world consumes an enormous amount of power, and non-renewable resources won’t last forever (obviously), so let’s take a look at some promising, weird, and awesome means of renewable energy generation…

 

Piezoelectric Wind Energy

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Figure 2: Energy Capture Using Piezoelectric Leaves (Credit: Cornell Computational Synthesis Lab)

 

This isn’t your ordinary wind turbine.  Power-generating wind turbines are spectacular, but they are gigantic, disliked by nearby residents, dangerous to flying wildlife, and they require a ton of space.  So what if we could scale down wind harvesting into something much smaller?  Piezoelectric wind harvesting uses small “leaves” fitted with vibration-sensitive piezoelectrics (Figure 2).  When they flap in the wind, the motion is converted to electricity.  The power that can be obtained from these is still quite small (Li, 2011), but they offer the unique ability to placed almost anywhere.  For example, they could make up the façade of a structure, similar to the ivy that creeps up many buildings.

 

Meat Power

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Figure 3: A Microbial Fuel Cell

 

No, that’s not a typo – researchers at Bristol Robotics Laboratory have recently devised a microbial fuel-cell that is capable of generating electricity by digesting bugs (Figure 3). Bacteria inside the fuel cell digest biomass, and devices powered by this fuel-cell are able to steal and utilize the electricity that results.  In their research video, they demonstrate a clock that can power itself by attracting bugs to its revolving flypaper and a driving robot that can run for 12 days on just 8 flies.  The project derives its idea from carnivorous plants that ingest insects to supplement their diet with extra nitrogen.

 

Underwater Turbines

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Figure 4: Scaled Down Model of the Underwater Turbines (Credit: Daily News)

 

Imagine a wind turbine.  Now, stick it underwater.  That’s essentially the idea behind Verdant’s generation-five water turbines (Figure 4) which will soon be gracing the bottom of the New York City’s East River.  About 30 of these turbines will be placed at the bottom of the river to generate energy from the water’s strong current.  This energy will be pumped into the electrical grid where it can power portions of the city.  There are already plans to begin installing these turbines in other places, assuming the successful performance of the devices in the East River.  The 4th generation of the system has already successfully delivered 70 megawatt hours of grid energy to NYC customers (Verdant).

 

Biogas Anaerobic Digestion

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Figure 5: Biogas Plant


A lack of clean renewable energy sources is far from the only problem that we face; humans also produce an inordinate amount of waste, both biological and inorganic.  Biogas plants aim to resolve part of this problem while simultaneously providing a source of renewable energy (Figure 5).  Similarly to the microbial fuel cells explained earlier, anaerobic generation employs microbes to break down organic matter and release a methane/CO2 mixture call biogas.  The biogas can be harvested to provide cheap, clean, on-site energy.  This form of power generation is ideal for energy reclamation at waste sites that already have biomaterials available for breakdown (Energy News, 2010).  However, it’s not highly feasible as a means of distributed power due to the refinement required to turn it into usable natural gas.

 

Those are just a few interesting new means of creating energy – it’s far from a comprehensive list.  Have you stumbled across any really cool new forms of electrical energy generation?  Let me know if the comments, I’d love to hear about them!

Sustainability is a loaded topic.  Nobody really knows what it means – there are definitions, ideas, and opinions, but as far as I can tell, there is no single way to identify what it truly means and how we can achieve it.  As an Electrical Engineer (in training), the thing I hear most commonly associated with being more sustainable involves new, more efficient means of renewable energy generation and storage.  If there is anything I’ve learned in my past 3 years of dealing with Sustainability-related projects and teams at my university, it’s that renewable energy is NOT the only way to achieve a more sustainable future.  In fact, it’s only a small part of it.

 

I’ve fallen into this trap myself – as an engineer I’m always looking for opportunities to build the next big thing; In the case of sustainability, that next big thing is the latest, greatest form of efficient renewable energy generation.  Here’s the unfortunate truth – it’s next to impossible for our society to become energy independent in the near future.  In fact, the world’s dependency on fossil fuels will not be broken for at least 30-50 years (Bryce, 2009).  It’s not hard to deduce this fact if we look at the world’s energy consumption over the last 200 years (Figure 1).  It’s increasing exponentially as a result of increased population, increased availability of high technology, and the industrial revolution.  While developing new means of energy production is important, it’s equally as important that we consider the other ways in which we can contribute to reducing our impact on the environment helping others to do the same.

 

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Figure 1 – Global Energy Consumption in Exajoules

 

So, as engineers and citizens of the world, how can we move towards developing a greener planet?  The first step is to consider sustainability on several levels.  While energy sustainability is an important component of becoming more sustainable, there are other important aspects of sustainability, as I hinted earlier.  When designing new products, conceiving exciting new ideas, or thinking of ways that we can “engineer” our way to a greener planet, it’s critical to consider the social, economic, and (unfortunately) political sides of sustainability.

 

For those of you who read my blog (http://www.jeremyblum.com), or follow me on twitter (@sciguy14), you might know that during my freshman and sophomore years at school I was a team leader on Cornell’s Solar Decathlon Project. At the bi-annual Solar Decathlon Competition hosted by the Department of Energy, teams from across the world design and build solar-powered homes to display on the National Mall in Washington, DC (Figure 2).  These homes do an enormous amount to promote renewable energy research, and the competition certainly taught me a tremendous amount about what it really means to “go green”.  But, my most important realization was, “It’s not enough”.

 

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Figure 2 – Cornell University’s “Silo House” Entry into the 2009 Solar Decathlon Competition (Credit: Chris Goodney)

 

After completing the competition, and planning with my fellow team leaders for the 2011 competition, it dawned on us that Solar Decathlon was not enough – Solar energy alone cannot free us from our oil dependence, and it’s totally impossible to plop an energy-neural solar-powered house onto everybody’s property.   It was time to approach sustainability in a more complete fashion.  That approach is something that we’ve been developing over the past year and a half with the reformation of Cornell’s Solar Decathlon Team into “Cornell University Sustainable Design (CUSD)”.  We have yet come up with a concrete definition of Sustainability, and I doubt we ever will, but we have developed projects that we believe will allow us to better comprehend, and therefore tackle, the broad issue of “being sustainable”.  We administer two projects right now, “Schoolhouse: South Africa”, and “The Sustainability Research Facility”.  The first project is designing and building an early-childhood education center/community center which will foster local collaboration, educate children, and provide for community engagement within the town of Cosmo City, South Africa.  The second project focuses on the development and construction of a “living laboratory” on Cornell’s Ithaca campus that will foster cross-disciplinary sustainability education and research.

 

So how does this all relate back to being a sustainable engineer?  As engineers, it’s easy to jump to the conclusion that best way for us to contribute to the green movement is to design more efficient electronics, use greener materials, et cetera.  But what I would argue is that we need to take a step back and consider how our decisions as engineers impact the global community, both socially and economically.  Our goal with these CUSD projects is to expand sustainability into realms where it ordinarily does not venture – a course that I would encourage all engineers to explore.  While it’s still important that we design products with minimal environmental impact, and that use little energy, it’s just as important that we consider how products promote (or discourage) their users to decrease their impact on their environment.  Take the Tata Nano for example, the world’s most affordable car.  It offers mobility to an entirely new class of people in India, but simultaneously lends itself to becoming a perpetuator of fossil fuel consumption.  Viewed from another angle however, the increase of passenger cars in India may encourage the subsidized creation of improved travel infrastructure, and a move by other car manufacturers towards the exceptionally low emissions and high MPGs that a car like the Nano offers – an obvious gain for the environment.

 

Long story, short?  Renewable energy is not synonymous with being more sustainable, it’s just a part of it.   We need to accept the fact that no single breakthrough in renewable energy is suddenly going to save us from ourselves.  Our energy demand will continue to rise over the coming decades, and the best way to handle it will be approach the problem with the knowledge that all actions we take need to be socially responsible, economically feasible, and will need to incorporate a plethora of technologies and ideas from a great swath of professionals, companies, and governments.  Engineers alone cannot eliminate our oil dependence, but they can develop the products, ideas, and movements that will allow the rest of the world the unanimously pursue the goal of global sustainability.