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Breakthroughs in Piezoelectric Power: Raising Public Awareness is a Step in the Right Direction for U.S. Sustainable Development

Kim Diamond's picture
Vice Chair of the Carbon and Energy Trading and Finance Committee, ABA,

Kimberly E. Diamond is a Vice Chair of the Carbon and Energy Trading and Finance Committee of the American Bar Association's Section of Environment, Energy, and Resources. Kim has practiced...

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  • Apr 17, 2009

Piezoelectricity is not a new concept to physicists and engineers. The word "piezoelectricity" is derived from the Greek words "piezo" or "piezein," which mean "to squeeze or press." French scientists discovered this technology in the 1880s. In basic terms, piezoelectricity is the ability of select materials, such as quartz crystals and certain ceramics, to generate an electrical charge when a form of mechanical pressure is applied. The applied charge generates voltage across the material. Common devices that use piezoelectrics include quartz watches, sonar, and motion detectors. Gas lighter wands also draw upon piezoelectrics, as squeezing the lighter trigger causes impact on a piezoelectric crystal, which in turn produces enough voltage to produce a spark and ignite the gas.

Applying the "Crowd Farming" Concept

Today, there are many more remarkable uses for this previously little-hyped technology. Through modern research and development, the kinetic energy people produce when walking or dancing can now be harvested through the use of piezoelectric floors and floor mats. Thanks to the piezoelectric dance floors installed in London's Club Surya, an eco-nightclub launched in July 2008, and Rotterdam's Wvatt, a sustainable dance club launched in September 2008, all dancers at these establishments truly have electric moves. The clubs' "bouncing" dance floors are engineered with springs and series of crystal and ceramic blocks. When patrons at each club dance, the pressure they exert on these blocks causes the dance floor to depress slightly and the blocks to rub against each other. The result is the generation of a small electric current. This process effectively captures the dancers' kinetic energy, and feeds it into nearby batteries. In Club Surya, for instance, batteries power the club's lights and air conditioning, and supply up to approximately 60 percent of the club's energy needs. As long as clubbers dance, the floor's movement constantly recharges the batteries. The more dancing, the more power produced. Each person can produce between five and 20 watts, depending on their activity level.

In addition to its application in foreign dance clubs, the concept of "crowd farming," or harvesting power from people's footsteps in crowded areas, has also been applied in overseas subway stations. In an effort to make train stations in the national Japanese railway network more energy efficient, the East Japan Railway Company (JR East) worked in conjunction with researchers from Keio University to embed piezoelectric pads in the floors under the ticket gates in Tokyo Station. Because high volumes of passengers pass through these gates on a regular basis, a respectable amount of electricity is produced. Similar to the mechanics used in piezoelectric dance floors, crystals embedded in the piezoelectric pads convert the vibrations and pressure from people's footsteps into electrical charges. These charges are routed to highly efficient power storage systems that provide clean power to other parts of the station, including the lighting fixtures. JR East envisions using this "people power" to operate automatic ticket gates or electric displays in the near future.

Taking the crowd farming concept a step further, innovators in Israel have recently unveiled perhaps the most novel electricity-generating surface to date: a piezoelectric road. The roadway containing this technology has an asphalt surface in which piezoelectric crystals are embedded. Similar to the way gargantuan footsteps would create pressure on a floor or mat, vehicles' turning tires create pressure on the road. When vehicles pass over the road, the road's embedded crystals transform the vehicles' kinetic energy into an electrical current. The current then runs to a larger transformer, which then distributes the energy. In addition to working in asphalt, these crystals and transformers also work in other surfaces, such as concrete. The beauty of this technology is that the piezoelectric generators not only may be installed in new roads, but they also may be incorporated into existing roadways that are being resurfaced. It is envisioned that due to the generators being only a few centimeters thick and being able to cover expansive surfaces, these generators in the future could be adapted for use in railways and airport runways.

Imagining the Possibilities for a Brighter Future

If U.S. business people and policy makers endorsed the implementation of high-tech piezoelectric devices such as those discussed above, there would be profound implications for investors, business owners, and local sustainable development planners. From a business perspective, entrepreneurs in the clubbing industry who install piezoelectric floors could attract to their venues customers who want to be viewed as hip and eco-friendly simultaneously. Private health and fitness clubs that install piezoelectric floors or mats in their main aerobic exercise rooms could gain additional notoriety, thereby attracting a health-conscious and energy-conscious clientele that may have otherwise contemplated joining other gym facilities.

On a grander scale, for large commercial real estate properties such as office buildings or shopping malls, the owners and tenants alike would reap economic benefits from installing piezoelectric floors or pads. A property containing such flooring would likely draw attention and garner local, if not regional or national, publicity. In the public's eye, the structure would be transformed from an ordinary structure into a unique, landmark location, which could raise the building's property value. Based solely on the panache of being located in one of the first U.S. commercial properties to install and showcase piezoelectric flooring, tenants could benefit in the short term from having an address at such a visible location. Presumably, the novelty of having such fascinating flooring throughout -- or at a minimum, at entrances and exits where foot traffic is the heaviest -- could attract guests and tourists who ordinarily would not have visited such building, thereby generating additional foot traffic and energy for the building itself. In the case of storefront tenants in malls, this extra foot traffic could pay off insofar as the additional consumers visiting the property may generate more revenue for these tenants. Moreover, tenants could benefit from the potential rent reduction they would receive from the building's owner(s) passing to them the cost savings realized through the building's producing its own on-site electricity and its corresponding reduced electric utility bills.

Because wide-scale domestic publicity about piezoelectric technology has not occurred thus far, U.S. cities that could substantially benefit from this clean, sustainable technology may not yet comprehend the realm of possibilities available to them. For instance, select groups of people, such as architects and engineers, may be aware of the piezoelectric sidewalk in Ann Arbor, Michigan, that powers LED lights in the sidewalk itself. However, mainstream newspapers and other media have provided little national exposure about the manifestation of this technological breakthrough on domestic soil. This absence of sufficient news coverage should not result in a failure to spark Americans' imaginations of how to capitalize upon piezoelectric building and infrastructure development. Imagine how much power could be generated by installing piezoelectric flooring at just one dance club, large office building, mass transit station, or sidewalk segment in a large pedestrian area. If sidewalks on the Las Vegas strip or in parts of New York City, such as in the Times Square or Rockefeller Center area, were retrofitted using piezoelectric technology, the constant, heavy foot traffic on these walkways alone could likely generate a substantial amount of energy -- potentially enough to light several city blocks. The continuous foot traffic on piezoelectric floors or mats in major subway, train, or bus stations, such as in New York's Penn Station or Grand Central Station, could power the lighting or automatic turnstiles at these locations.

In the infrastructure development area, piezoelectric technology could benefit states and other private owners of interstate routes, roadways, and heavily trafficked thoroughfares. Congested highways and freeways could undergo a transformation -- no longer would their sole purpose be to facilitate pollution-emitting, fossil fuel-burning modes of transportation. Rather, these roadways could be tremendous lifelines that pump clean energy back into the energy grid. The busier the roadway and the heavier the vehicles, the more energy that could be produced and harnessed. It is mind-boggling to think of the collective amount of electricity that could be generated from the 405, the 5, or the other freeways in the greater Los Angeles area, the Capital Beltway in the Washington, D.C., area, or the turnpikes and parkways surrounding New York City. Interstate routes monitored by local state authorities would reap the benefit of being able to retrofit roadways with piezoelectric technology during standard maintenance intervals, rather than paying an extra premium for having to develop additional sites flanking these roadways to install completely new infrastructure for other alternative energy projects. Even in smaller cities, heavily trafficked streets could potentially produce a sizeable amount of energy.

Investing in Ground Floor Opportunities

Of course, as is true with investments in other cutting edge technologies, investing in domestic piezoelectric flooring and roadway projects entails risks and has its downsides and challenges. Due to the uniqueness of this technology, there are relatively few manufacturers of the necessary piezoelectric materials. This limited supply of distributors, coupled with the scarcity of the products on the global market, causes the price for piezoelectric materials to be quite high. Also, because the technology is still relatively new and in an emerging developmental stage, there are design improvement issues related to durability and power generation efficiency that still need to be addressed. Additionally, the cost of capturing, transmitting, and converting the current generated from the capture of kinetic energy are quite high. This may be problematic for owners contemplating installing piezoelectric flooring or roads on their property for several reasons. First, the costs associated with piezoelectric flooring and roadways may outweigh a contemplated project's projected monetary benefits, particularly in the short term. Second, owners who cannot afford the costs of start-up capital for piezoelectric installations may experience difficulty obtaining financing from traditional sources. Specifically, lending institutions tend to be conservative and risk adverse. Because of the extremely limited history and track record of piezoelectric flooring and roadway projects nationally and internationally, these established financial institutions may deem the piezoelectric project too risky and determine not to finance the project. Securing funding sources for contemplated piezoelectric projects, particularly in the current limping economy, may prove challenging.

On the other hand, there is a definite upside to investing in U.S. projects aimed at incorporating piezoelectric technology at this time. While investing in any relatively new technology is risky, investing in piezoelectric technology while it is still in its infancy could prove to be quite lucrative. With higher risks often come greater rewards. By taking a calculated risk and investing in projected growth areas for future piezoelectric projects, such as retrofitting or building new shopping malls, stadiums, airports, highways, and commercial real estate buildings that employ piezoelectric devices, venture capitalists and other savvy investors could stand to profit greatly over the long term. New advances and breakthroughs in piezoelectric technology could emerge during the approval stages of the project, and be integrated into the building phase of the project, given the time between when the initial investment in the project is made, and the time that elapses before actual construction begins. This could be an attractive feature for consortiums interested in securing a 50-year or other long-term concession for building, financing, operating, and maintaining a fixed stretch of a roadway corridor, such as between interstate routes and toll roads.

Also, companies and business owners who incorporate piezoelectric technology into new buildings' architecture or who retrofit existing structures with this technology will garner positive press and enhance their reputation as being a leader in this futuristic clean technology area. These entities would be viewed as "good deed enablers," due to their promoting and facilitating other people's ability to perform the meritorious, charitable act of donating their own kinetic energy for the greater social good.

Creating a Class by Itself

From an investment banking perspective, if a certain threshold of increased demand is reached over the next decade or two for secured borrowing for large-scale piezoelectric projects, then there is the potential that a new esoteric asset class involving piezoelectric loans or bonds could be formed. The creation of such securities, backed by infrastructure-related or commercial real estate-related debt, could herald additional transaction structuring and trading opportunities in the capital markets. For instance, asset-backed securities in the form of piezoelectric infrastructure or commercial real estate loans could be used in the future as collateral for structured finance transactions such as collateralized loan obligations (CLOs), or other structured investment vehicles. Other innovative fixed income securities incorporating the cash flows from piezoelectric bond receivables could also be formulated, structured, and traded.

As a matter of policy, it makes sense to engage in robust discussions about the merits and feasibility of promising technologies for incorporation into the current potpourri of available alternative energy and sustainable development options. Piezoelectric flooring and roadway technology warrants such discussion. Increased domestic public discourse will not only raise the profile of this technology nationally, but it will facilitate Americans' ability to participate more vigorously in the larger global dialogue focused on the development, refinement, and implementation of this technology worldwide. Failure to partake in such endeavor may have a detrimental impact on the U.S.'s ability to shape or influence the course of how this technology evolves in the global marketplace. A lack of awareness of opportunities involving piezoelectric technology may also preclude U.S. participation in piezoelectric project finance endeavors and other integrated finance and technology transactions being contemplated elsewhere in the world. It may also slow the emergence of future structured finance products based on the expected income streams from piezoelectric bond or loan receivables.

To achieve and maintain the status as a global leader in the sustainable development arena, the U.S. must be more proactive in its communicating to the general public newsworthy achievements and other technological breakthroughs in the alternative energies space, such as piezoelectric flooring and roadways. As a national community, our collective deficient knowledge about groundbreaking projects in other countries that involve piezoelectric technology may limit our ability to take advantage of developments in this growing area and be a future market leader in structuring novel financial transactions involving securities backed by piezoelectric-based assets. Domestic policymakers, business leaders, and others now have the unique chance to capitalize on piezoelectric technology while it is in its infancy. It is to our advantage as a nation to supply such people with sufficient information and public input about this technology so that they will be in a better position to make informed investment decisions and to choose whether to advocate for this technology's implementation at this time. Other countries are testing, financing, and starting to embrace state-of-the-art developments in piezoelectric technology. As a country, it is time we followed step.

Ferdinand E. Banks's picture
Ferdinand E. Banks on Apr 18, 2009
I'm 100% in favor of some of the things mentioned in this article. Some of them! Yesterday I paid a visit to the university gym where I generated quite a few piezo-watts, and tonight I visit Stockholm's great dance 'place' NALEN, where I will be responsible for a few more.

As long as we do not bring scams like the deregulation of electricity and cap-and-trade into the picture, you can sign me up as an enthusiast.

Jason Marks's picture
Jason Marks on Apr 21, 2009
My understanding of physics is pretty rudimentary, but I am pretty sure that generating electricity using piezoelectric principles is not cost-free. For the example in the article of using the pressure/weight of car tires rolling down the road, I have to assume that there are corresponding losses of fuel economy to the vehicles. Piezoelectric devices might turn out to be efficient means of harvesting sources of kinetic energy that are currently undeveloped, such as wave power.
Len Gould's picture
Len Gould on Apr 22, 2009
I was trying to puzzle out what the heck might motivate the installation of vast arrays of costly electronic devices in eg. dancefloors at 60 watts / sq meter with a capacity factor of perhps 2 evenings a week. then I saw :

[QUOTE]there is the potential that a new esoteric asset class involving piezoelectric loans or bonds could be formed. The creation of such securities, backed by infrastructure-related or commercial real estate-related debt, could herald additional transaction structuring and trading opportunities in the capital markets. For instance, asset-backed securities in the form of piezoelectric infrastructure or commercial real estate loans could be used in the future as collateral for structured finance transactions such as collateralized loan obligations (CLOs), or other structured investment vehicles. Other innovative fixed income securities incorporating the cash flows from piezoelectric bond receivables could also be formulated, structured, and traded.[/QUOTE]

That's what it's all about, actually. Back at the same old games.

Xuguang Leng's picture
Xuguang Leng on Apr 23, 2009
Piezoelectricity is surely feasible, but whether it is economically is a whole different question.

You are trying to collect a very low density energy product and make it useful.

If you spend enough money, you can turn desert into productive farmland, but it would not be economically.

If you spend enough money, you can generate piezoelectricity, but it would not be economically to do so.

Jim Beyer's picture
Jim Beyer on Apr 27, 2009
This is an utterly ridiculous proposal. The amount of energy that can be harvested is tiny compared with the investment required. It is articles like these that make me worry that people really don't get the problem we are in. While some may debate just what our problems are, the above article is no solution to any of them.

We need to quit with the funding and advancement of "feel-good" greentech appliances such as this. In the end, it will only hurt us further when the rest of you figure out what a poor use of resources this really is.

Piezoelectric technology is great for powering small things that are hard or inconvenient to power. Check out, for example.

Richard Vesel's picture
Richard Vesel on Apr 28, 2009
Anyone who can do basic math will see that this concept is a COMPLETE hoax.

If you get on an exercise bike, rigged to a very efficient little mechanical generator, you have to peddle your butt off to light a 60 watt bulb. Piezoelectric conversion is far less efficient, from a basic energy conversion principle, as well as from an inefficient connection between the force generator and the so-called "generator". One person, working full out, could not power a conventional air-conditioner for a small room. A roomful of occasional dancers, even energetic ones, could not power the AC and/or lighting for a club environment.

How much energy do you think is coming from someone operating one of the new "hand-cranked" radios or flashlights? You have to crank for about one minute to get 5 minutes of flashlight at about 3 watts, or 30 minutes of radio play, of about 0.5 watts.

Lighting and airconditioners use THOUSANDS of watts, continuously. One thousand people, furiously cranking or peddling away continuously on little mini-generators, still will not power the lights and AC for a small club, by at least one order of magnitude, no less run the refrigeration system for all the drinks they are going to need to consume to keep their bodies and psyches properly lubricated for the futile task...



I will be more than happy to send an excel sheet with real numbers to anyone who needs convincing.

This is a huge article pumping smoke up everyone's

Richard Vesel's picture
Richard Vesel on Apr 28, 2009
Read a recent and reputable study on the topic by LANL and Virginia Polytechnic:

At best, 1-4% efficient, with continuous input power efficiently coupled into the converting device. No dance floor would come close.

Kim Diamond's picture
Thank Kim for the Post!
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