Even if the planet doubled the amount of solar and wind power available tomorrow, there would still be a shortage of clean electricity. We need to grab energy from wherever we can find it, which is why piezoelectricity—the charge that gathers in solid materials like crystal and ceramic in response to strain—has recently begun to pique the interest of entrepreneurs and scientists alike.
A number of materials are piezoelectric, including topaz, quartz, cane sugar, and tourmaline. That means a charge begins accumulating inside these materials when pressure is applied. Piezoelectrics are already commonly used in a number of applications. Quartz clocks, for example, rely on piezoelectricity for power, as do many sensors, lighters, and actuators. But these are the old uses for piezoelectricity. Scientists today have much more interesting piezoelectric plans in mind.
One of the most popular uses for piezoelectricity in the past few years relies on roads and sidewalks. It all started in 2008 with Club Watt, a dance spot in the Netherlands dubbed the world's first sustainable dance club. The club installed piezoelectric materials in its dance floor to turn patrons' moves into electricity that is used to change the color of the floor's surface.
After Club Watt, the piezoelectric floors kept coming. A Tokyo railway station installed a piezoelectric floor that uses kinetic energy to generate 1,400 kW of energy per day—enough to power ticket gates and displays. Toulouse, France, recently became the first city to put pressure-sensitive piezoelectric modules on the sidewalk, generating enough energy to power streetlamps. And the United Kingdom plans to install power-generating tiles on London streets to light up bus stops and pedestrian crossings.
Piezoelectrics are also increasingly becoming common on roads. In 2009, a British supermarket installed kinetic road plates that collect energy from customers driving over road bumps in the store parking lot. The road plates are pushed down by vehicle weight, which creates a rocking motion that turns generators. The system is used to power the supermarket's checkout lines.
In Israel, a company called Innowattech is installing strips of asphalt embedded with piezoelectric materials. According to the company, the generators could produce 1 MWh of electricity from a four lane highway, or enough to power 2,500 homes.
The technology just keeps getting better, too. Last year, Princeton University researchers combined silicone and nanoribbons of lead zirconate titanate to create PZT, an ultra-efficient piezoelectric material that can convert up to 80 percent of mechanical energy into electricity. PZT is 100 times more efficient than quartz. It's so efficient, in fact, that the material could be used to harness energy from the minute vibrations found in items like shoes and clothing. That means a piezoelectric-equipped shirt could potentially charge up your cell phone after a day of activity.
Piezoelectric sidewalks, roads, and clothing items haven't taken off in a big way quite yet, but they probably will soon. As we become more reliant on having fully-charged gadgets with us at all times, a shirt or pair of shoes that can prevent a device from dying will be incredibly valuable.
Love it! I've been looking at ways to lower energy bills, because they're only going to get higher. The best way is currently to insulate well and conserve. I just paid off a 5 year home improvement loan on new windows, insulation and siding. Wind and solar aren't there yet for the homeowner unless the govt. wants to provide incentives, like Germany.
Nikola Tesla (the guy who invented AC current and, I assume, the namesake for the Tesla Transducer) had worked out a way to get electricity out of the air, but the secret seems to have died with him.
It may be that a combination of devices - wind, solar, piezo shirts, and what-not will be the ultimate solution.
The exponential growth of the "alternative energy" industry in the last few years shows great promise in regards to the energy independence of the United States. For awhile now, the energy responsible for our success has been provided by fossil fuels; petroleum, natural gas, coal, etc. But we all realize that these are finite resources and the energy source that will power our future success lies elsewhere. The future of sustainable, clean power lies in other, more abstract opportunities. Wind, of course, is a viable option. Solar, indeed, will also play a part. Tidal Wave is yet another viable method. Geothermal is particularly appealing due to its simplicity: basically stick a pipe in the ground, and you're done. Well, there's more to it but you get my drift. My favorite that I've been reading about lately is called Piezoelectric energy harvesting.
So generally Piezoelectric Energy Harvesting is based upon thepiezoelectric effect. Yeah, I know. Real ground breaking stuff. The essence of the piezoelectric effect works as follows: by applying a mechanical stress to a crystal, one can generate a voltage or potential energy difference, and thus a current. Also by applying a current to a piezoelectric one can stress or strain the material. The mechanical stress can be supplied by any source. But with so many people walking around from place to place, why not harness that kinetic energy to power stuff, right?
So with the basic idea layed out, how can this phenomenon be but to use in generating electricity. A lot of ways. One highly viable option is to lay piezoelectric crystal arrays underneath sidewalks, stairwells, and pretty much any other high traffic area to power street lights or whatever else you care to plug in. The armed forces toyed with the idea of putting piezoelectric materials in soldiers boots to power radios and other portable electronic gear. This turned out to be not feasible with current technology at the present time due to the extra weight and discomfort of the setup, but it may be possible later on. Several nightclubs, mostly in Europe have already begun to power their strobes and stereos using the force of hundreds of people pounding on piezoelectric lined dancefloors. Several gyms, notable in Portland and a few other places are powered by a comination of piezoelectric set ups and generators set up on stationary bikes. We're really just looking at the tip of the iceberg when it comes to the uses of human kinetic energy of people in motion to create energy.
Every week some new discovery concerning uses of piezoelectric energy is uncovered. Even though the idea has been around for awhile, in microphones, amplifiers, and other applications, electricity production in this area is in its infancy. One cool idea concerns piezoelectric nanowires embedded in clothing to create energy.
In the near future, the lights at your favorite coffee shop or the stereo system at your local bar could very well be powered by foot traffic. If we want to maintain a certain lifestyle in an increasingly competitive, resource strapped world, we need to think outside the box when it comes to energy production. There are a million sources of clean, environmentally conscious power all around us, we just have to explore and utilize these sources in the most effecient manner possible. Ambient energy capture will no doubt play a large part in the future of renewable energy, and there's no time like the present to work on developing new, innovative means of electricity generation. I feel confident in saying that the world of tommorow looks pretty bright, both literally and figuratively.