After watching one of those little Sterling Fan contraptions sitting atop a wood stove, I began wondering about using temperature variants and vibrations to power other things.
The Long Now Foundation’s “10,000 Year Clock” is designed translate the difference between daytime and nighttime temperatures into mechanical energy which winds the clock. But this involves a substantial amount of mass. I was looking for something a little smaller.
It turns out many teams are working on numerous solutions for application in variety of situations. Recently the area of piezoelectric materials has been getting a lot of work and finding many applications. Common ones include imbedding piezoelectric materials into shoes and harvesting energy to power mobile devices. The button ignitor common on propane grills is an example of a high voltage piezoelectric generator.
NASA, MIT, Cornell, Berkeley, and others are working on piezoelectric fibers which can be made into clothing (some of these fibers are also acoustically active).
University research programs have demonstrated many other small scale applications:
- remote structural monitoring with sensors embedded in buildings and bridges.
- asset tracking of items in transit.
- tire pressure monitoring systems.
- embedded medical devices.
At what may be some of the smallest scale applications, biology has shown the collagen in bone tissue has piezoelectric properties; and bio-engineers are working on materials which assist in numerous medical applications.
OK, musical fibers and bio-engineered tissues are interesting. But I was looking for something a little larger and less complicated to work with.
Fortunately others are taking the concept to much larger scales. Here’s a URL with a flash video (simulation) describing how an Israeli company Innowattech is incorporating piezoelectric pads into roads and railways to harvest some of the waste energy from transportation. The harvested energy is used to power infrastructure.
Research has also shown that piezoelectric materials provide a good way to insulate against vibrations and noise. Imagine using insulation materials which transformed that noise neighbors midnight music sessions into electricity to reduce your own utility bills. Anyone living near a busy roadway can appreciate the desire to reduce vibrations and noise. It would be fantastic if the solutions could pay for themselves by providing electricity.
In another large scale application, the East Japan Railway Company installed piezoelectric flooring at the Tokyo Train Station designed to produce up to 1400 kWh per day from passenger foot traffic. Each Japan Railway Company later added the technology to a second station.
Numerous nightclubs and fitness centers around the world have implemented similar flooring (often utilized to power interesting entertainment effects). California, Italy, and Canada are also looking to infrastructure scale implementations of this technology.
There are three more applications I haven’t observed yet, but would be very interested to see.
- Most cities around the world have tall buildings whose foundations and structures have to account for continous wind sway and vibration (in addition to seismic vibrations). The energy potential in these structures most be immense.
- Many communities around the world have areas with cobblestone streets. I’ve observed that many “upscale” shopping and business districts like to install cobblestone paving for the ascetic value and to help ensure drivers maintain slow vehicle speeds in areas likely to contain large number of pedestrians. From the appearance of the Innowattech piezoelectric devices, it seems reasonable to investigate creating some sort of “piezoelectric brick” for use in cobblestone paving. By combining this power source with smart lighting, we could provide street lighting where appropriate relative to the path of the vehicles and pedestrians while avoiding the costs and light pollution of traditional lighting.
- It would be interesting to adopt this sort of technology to embed into the foundations and structures of residential construction for “off-grid” construction.
It would be great if we could soon procure “piezoelectric bricks” for use in construction as easily as we currently find concrete cinder blocks. I would certainly look forward to living a quieter home with lower utility bills.