Dickson Piezoelectric Generator

From PESWiki

Richard Dickson proposes using the piezoelectric effect for generating electricity, where pressure turns into electricity, from environments such as wave action or roadway impact. The question is one of cost and feasibility, not whether or not it would work.

There would have to be a large-scale manufacturing process developed using benign crystal materials, strung together electrically, for this idea to have practical merit.

A provisional patent has been filed.

About Piezoelctricity

Piezoelectricity is the term for electrical current generated by mechanical stress, or pressure, applied to certain non-conductive solids. The effect was first discovered by the Jacques and Pierre Curie brothers in the 1880s. The Curie brothers applied pressure to common crystalline materials, such as cane sugar, salt, and quartz, and found that electrical charges appeared, and these charges were proportional to the stress applied.

Piezoelectric materials science has evolved from natural crystals, such as quartz, to exotic manufactured piezoceramic materials, which can produce various voltages under stress.

Subsequent developments in the field since then have led to the development of high voltage source devices, sensors, and actuators. Perhaps the most well-known application is the car cigarette lighter, airbag sensor, and the common doorbell buzzer. But the technology has also been useful in sonar development, ultrasound medical and non-destructive inspection applications, as well as electronics equipment.

Currently, the latest research revolves around “power harvesting” from vibrations using piezoelectric materials. Power harvesting is the term used to describe the process of acquiring the energy surrounding a system and converting it into usable electrical energy. This research has been sparked for the need for wireless power sources for the new wireless technology (WiFi laptop computers, cell phones, etc.). However, the research has been into mostly low voltage applications. [See Ref 1].

Power harvesting research has delved into piezoelectric applications mainly due to the development of powerful new composite piezoelectric ceramic materials. The lead titanate zirconate group and even newer lead-free ceramic materials seem to show the most promise for future applications over a range of compositions. [See Refs 2 &3].

Ref (1)

A Review of Power Harvesting from Vibration Using Piezoelectric Materials by H.A. Sodano, D.J. Inman and G. Park, Shock and Vibration Digest, Vol. 36, No.3, pgs 197-206 (2004).

Ref (2)

Piezoelectric Ceramics by Hans Jaffe, Journal of the American Ceramic Society, Volume 41:11, Page 494, November, 1958.

Ref (3)

Processing and Piezoelectric Properties of Lead-Free (K,Na) (Nb,Ta) 03 Ceramics, Journal of the American Ceramic Society, Volume 88:5, pages 1190-1196 (2005)

Energy Harvesting

• See Eight-page explanation and diagrams (http://www.freeenergynews.com/Directory/Piezoelectric/Dickson_Piezoelectric_Generator_061118.pdf) - includes much of the information that is contained here.

Mr. Dickson is pioneering ideas of using changes in water pressure for power harvesting, and has an earlier invention, the “hydrosphere”, which converts hydrostatic pressure to electrical current via pressure differentials and secondary effects.

However, “piezoelectric mats” represent a more direct way to convert the resonating pressure in the ocean or lake water column into electricity.

Essentially, this patent pending idea consists of embedding shaped (round, square or rectangular) piezoceramics, hereafter referred to as “piezoelectric cells”, into sealed, rubber coated mats, which would then be placed on sea or lake beds at depth. The mats are linked together via electric cable connections, and can be spooled onto the wenches of cable laying ships for laying down a large array in oceans or lakes. The embedded piezoceramics cells are linked in series within the mats, so that the combined effect of all the electricity generated from the vibrating water pressure in the water column directly above the mats is harnessed and transmitted to shore via power cables on the sea or lake bed.

Possible land-based applications include embedding large arrays of piezoelectric cells in close proximity at key, high-traffic chokepoints beneath the nation's freeway system. Good locations would be high volume freeway off-ramps or key intersections. Considering that over 100 million auto trips are made per day in the U.S., this is a considerable potential renewable, clean energy source that has been completely over-looked.

Additionally, auto and truck wheels could be designed (and possibly bicycles)to include piezoelectric cells embedded around the wheel axis with a mechanism for directing pressure onto each cell at the moment of road contact. If enough cells were used, this might generate sufficiently useful amounts of electricity to power batteries and electric motors.

In any case, due to the low voltage output of individual piezoelectric cells, ideas utilizing large arrays with piezoelectric cells connected in series are the only practicable options for use. However, this is not insurmountable, and analagous to similar problems with solar cells, since solar cells are also only commercially useful in large arrays due to their individual low-voltage output.