Category Archives: pragmatic choices

Energy harvesting — the siren’s allure

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My wife, Deborah Mills-Scofield monitors dozens of media outlets and forwards articles to me that might be of interest.  One recently came my way about an effort in Portland, ME to harvest hydroelectric energy from its water pipes.  A company, LucidEnergy, has developed turbines that can be installed for this purpose.  The basic idea is to capture free energy in municipal water pipes that would otherwise be wasted.

While I applaud such innovation and creativity, I find the effort is misplaced.  I predict these turbines, like solar panels of the 1970’s and green roofs of this last decade — will soon be removed and abandoned.  This kind of energy harvesting is a fool’s errand.

About a decade ago I learned about another energy harvesting project in Israel — to install piezo-electric tranducers in highways to capture energy from passing trucks.  As heavy vehicles passed over these tranducers the truck weight would cause the transducers to compress and produce electricity.  The promoters of this energy argued that normal road compression represented lost energy — their technology would capture energy that would otherwise be lost.  The installed transducers did, in fact, produce electricity.  But I am confident that careful analysis would show that this energy comes from slight increase in fuel consumption of the vehicles that pass over the transducers.  Highway rolling resistance is mostly due to compression of the tires, not the road surface!

I am not aware of any evidence that water passing through municipal pipes arrives at end destinations with excessive kinetic energy.  Therefore any energy harvested along the way is likely to have to be re-injected by pumps.

And the maintenance issues must be significant.  I envision a few years of testing at the end of which it will be concluded that the cost of maintaining these units far exceeds the value of the energy they generate.  And what about the maintenance of pipes which get plugged due to low flow velocity?

Nature has handed us sunlight, wind, and hydo energy.  Harvesting these abundant resources is proving to be a challenge.  Harvesting efforts should focus on these well-understood and low-maintenance options.

Humans clearly waste a terrific amount of energy.  And there are many different ways that this wasted energy might be harvested.  The problem is cost-effectiveness.

 

 

Hero Stories and Learning Stories

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Kathryn Janda and Marina Topouzi published an interesting paper at the 2013 Summer Study on Energy Efficiency sponsored by the European Council for an Energy Efficient Economy (ECEEE).  The title of their paper is “Closing the loop: using hero stories and learning stories to remake energy policy.”  Kathryn Janda spent a few years on the faculty at Oberlin College and refers to the College’s “trophy building” — the Adam Joseph Lewis Center as one of her examples.

Janda and Topouzi argue that “hero stories” describe something that is bigger than life and not realistic.  They draw parallels with narratives offered for energy efficient buildings and projects — the “stories” or claims are unrealistic and, all too-often, reality falls short of the promise.  In the end they argue that there is an interesting “learning story” in the reality — one that is all too-frequently left untold.

The paper is interesting and well-written — not at all like most scientific papers.  Rather than provide a poor summary of their paper let me provide this quotation from their abstract:

This hero story, where we are saved by clever technologies, is inspiring, positive, and familiar. In this story, we don’t need to do anything because the technology will do it for us. But how real is it? The counterpart to the hero story is the learning story, where things are not quite as simple as they first seemed. In a learning story, protagonists are normal people who need to rise to a challenge. They are not saved by Superman, they have to save themselves. The learning story in energy policy lies in the between the technical potential and what is achieved in practice.

The piece is a refreshing read.

Pertamina Energy Tower to generate all its energy — really?

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Fast Company has a short article by Adele Peters that describes some design features for the 99-story Pertamina Energy Tower that is planned for construction in Jakarta.
The building, designed by Skidmore, Owings & Merrill, will be the “first supertall tower in the world to generate its own power” apparently by capturing wind power at the top of the building and sucking geothermal from the bottom.  Excuse me if I am a bit skeptical.

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Flash back 15 years to a different architect — William McDonough — whose firm designed the Oberlin College’s Adam Joseph Lewis Center.  Bill is the standard bearer for architects that make fantastic claims backed up by little substance [Green guru gone wrong – Fast Company].  This success requires a media willing to publish such claims years before we ever see the fruit of the work.  When the fruit finally arrives — shriveled and disappointing — it matters little because the architect has moved on.

Consider Oberlin College’s Adam Joseph Lewis Environmental Center.  Long before its construction in 2000 McDonough was claiming he had designed a zero energy building — one that would be powered by solar cells mounted on its roof.  Through the years his claims never wavered.  Never mind that, following construction, the building consumed three times the energy his firm claimed it would [Early performance of a green academic building – ASHRAE] or that years later, after hundreds of thousands of dollars of HVAC modifications, it consumed double his initial projections — less than half the energy provided by its rooftop array.  Now, after 12 years of false claims the building has finally moved “into the black” powered by a $1,000,000 PV array constructed over a nearby parking lot which, combined with its $400,000 rooftop array, produces 3X as much energy as the the design team projected for the building.  [A paler shade of green – HPAC Mag]  I wonder how much attention McDonough would have gotten in 1998 had he told the world that he had designed, at a cost of $500/sf, a 14,000 sf building that used 20% less energy than conventional buildings and was to be powered by PV panels covering its roof and a parking lot, costing $1,400,000.  (That is an additional $100/sf just for the solar arrays.)  Excuse me Mr. McDonough — what was your “value added” — publicity?

But this post is about another project — the Pertamina Energy Tower.  My point is this.  Talk is cheap.  There is little doubt that this building will not deliver on its promises.  But for now the architects can spin their exciting story to media who don’t ask the hard questions — like “wouldn’t a shorter, fatter building be cheaper and use less energy? Or, “how much rental space is lost to provide space for the wind turbines and what is the cost/benefit of this?”  Physicists are good at “back of the envelope” calculations.  A 99-story building seems like an expensive way to mount a wind turbine.

Attention College students: Environmental choices are not black and white

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My institution, Oberlin College, has been burning coal to heat its buildings for probably over 100 years.  The practice continues today.  The College is concerned about the pollution associated with this and has developed a plan to phase out coal and phase in natural gas.  But Oberlin College Environmental Studies students want more — they oppose this plan and insist on a much more aggressive plan to reduce carbon.  They push plans that call for heating all buildings with ground-source heat pumps, powered by green electricity.  They naively believe that using electricity produced by landfill gas will provide our green future!  (Hello!  Utilizing someone’s waste stream is a smart opportunity but it does not scale to the nation unless we grow the waste stream.)  The problem, of course, is that greening the grid will take decades (at best).  Replacing coal with natural gas will significantly reduce carbon emission NOW, buying time for more aggressive changes in the future.

Brett Stephens addresses this very thinking today in his opinion piece in the Wall Street Journal where he discusses the Keystone Pipeline in the context of the recent runaway train explosion in a small Quebec town just north of the Maine border.  He is bang on when he asks the question, “Can Environmentalists Think?”

This is exactly what pragmatic stewardship is all about.