The whole concept is based upon two core technical ideas:
Idea #1. Use electrical Capacitors to replace batteries (primary or
re-chargeable) in portable appliances ("Power Capacitor").
Idea #2. Use innovative electrical generators driven by human muscle energy
to charge this "Power Capacitor".
The combination of these two leads to the development of environmentally clean 100% renewable alternative energy source with high readiness. This concept in a form of simple one-line equation could look like this:
Mobile Electricity = Muscle powered electrical generator + Electrical Capacitor as energy storage
In a short form : E (Energy) = M (Muscle) + C (Capacitors), or very familiar: E=MC, without square (just a joke).
WHY CAPACITORS ?
Here I will try to provide the popular explained, thus a bit over-simplified Capacitor-replacing-Batteries concept.
In the context of the GEL Initiative the core difference between Capacitors vs. Batteries is a maximum number of charge/discharge cycles. Standard non-rechargeable Batteries by definition has a single discharge cycle: after that they must be disposed. This generates a huge environmental problem of proper batteries disposal as they could contain a potentially hazardous materials (more on this topic you will find later in the article).
Rechargeable batteries slightly improve the situation, providing typically 200...500 charge/discharge cycles. Their is a substantial performance degradation as a battery goes closer to its limit. After the battery exhausted the charge limits, it should be disposed. Battery performance is highly dependent on the proper charging, thus the charge cycles could lasts for hours in order to preserve the batteries performance spec. Rechargeable batteries are very sensitive to the discharge mode: some of them could be severely damaged by short circuiting and can even cause the fire.
Capacitors, to the contrary, have practically unlimited number of charge/discharge cycles; it could easily go to millions and tens of millions cycles. They are mostly immune to the short circuiting and high charge current, thus the charge cycle could be made very short: seconds vs. hours required for the batteries. And on-the-shelf life time of the capacitors are much higher than of any battery type.
There are also some differences in terms of Power and Energy density: Capacitors typically provide better Power Density while Batteries (some of them) are doing better in terms of Energy density.
I would like to notice, that this quick introduction in no case can replace the thorough engineering discussion on this topic It was not even intended to do so. The goal of this popular explanation is to highlight the essence of GEL Initiative, i.e. the revolutionary transition from Batteries-powered portable electronics to much more environmentally friendly Capacitor driven design.
HISTORICAL MILESTONES
It's relevant to mention, that the use of capacitor as an energy backup has a pretty long history. I could trace the idea of using electrical Capacitor instead of Batteries 30+ years back, to mid 70s. At that time space era just started (2 decades before, to be exact, in 1957) and brought a lot of excitement to teenagers over the world. The whole generation was dreaming about space exploration and rocket science was a buzz word of the day. Building small rockets in our back yard I was using electrical Capacitors with tiny filament as a portable ignition system, so I saved some money on the Batteries (that time batteries were relatively expensive stuff, especially rechargeable ones).
I have published the design idea of using electrical capacitor instead of batteries (primary or re-chargeable) to power commercial portable audio appliances in 19971; it brought me the “Best Design Idea” award based on the EDN Magazine readers vote. At the time of publication Capacitors were already widely used as power backup (for example, in a car jump-start devices, or as a memory power backup in personal computers, etc), but practically all of the varieties of such known applications utilized the Capacitor as an auxiliary energy source. To the contrary, the article1 was focused on the idea and design principles of of total battery replacement and using electrical Capacitor as primary energy source in portable applications (battery-free application concept).
Funny enough, long before this practical design idea was published, I had plenty of discussions about the feasibility of such solution. Once the friend of mine made a "strong scientific argument" against even theoretical possibility of such devices: "It's known that ideal Capacitor has theoretically infinite equivalent internal DC resistance; so, how it can generate any DC electrical current if the circuit is open?" Good example of pseudo-scientific paradox, isn't it ? I guess my readers with some basic knowledge of Electrical circuits and systems could easily find the logical deficiency in that statement made against Capacitors' DC power capabilities.
Here I just want to reiterate key advantages of Capacitor vs. any rechargeable battery: practically unlimited number of charge-discharge cycles, high endurance to short circuits and simple requirements to the charging device as there is no theoretical limit to the charge current (the circuit just needs to protect capacitors from over-voltage). The capacitor charging cycle could be made very short, thus increasing the overall device readiness. As the life cycle of the capacitor is practically unlimited, there will be no disposable parts, thus the whole solution is potentially very environmentally clean.
In the year 2002 I have expanded the idea of battery-free portable applications to the concept and design principles of what was named at that time an “organic” electrical power: muscle-powered electrical Generator with big Capacitor or rechargeable battery as energy storage. Such alternative “renewable” DC power supply could be used either totally autonomously or in conjunction with other alternative energy sources (solar cells, for example) to power the vast variety of portable electrical and electronic devices: cellular phones, CD/MP3 Players, AM/FM radios, PDA and handheld PCs, digital cameras, flashlights, etc. It could also serve as a valuable part of any emergency and survival kits.
I have tried to introduce this revolutionary new solution to
the wide engineering community through
the popular trade publications.
One of my submissions was titled as: "Alternative
energy source is muscle-powered: New York City Blackout-2003, The Day
After”. I would assume that readers still remember that event; I even
got a dedicated T-Shirt (see the picture to the left).
This slogan/campaign-style title did not help me much,
though I still think that the idea was quite in time. 2 years later my article was
eventually accepted by the highly popular EDN Magazine 1 .
The article describes practical design solution of using muscle power to
be converted into electrical current and subsequently to charge the big
capacitor. It was written for engineering community, thus containing the
variety of highly technical details and design consideration.
The same time my "GEL Initiative" managed
to climb to the top of the list on Google search engine.
So, let's talk a little about the
technological and environmental issues "GEL Initiative" is able to solve.
ELECTRICAL BATTERIES DISPOSAL: HUGE ENVIRONMENTAL PROBLEM
The following pictures were taken at NY Subway station, pretty close to my home. Any regular day you could see the pictures like this in the areas not limited to just Subway stations, but almost everywhere in the City (probably, with certain extent of generalization: everywhere in the State, Country, planet... except for some uninhabited isles somewhere out there, may be).
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FIG. A, B, C, D: ENVIRONMENTAL CONTAMINATION WITH DISPOSED BATTERIES
These scenes are brought here NOT for the purpose of blaming someone, accusing or finger pointing, but in order to highlight the epic proportion of the environmental problem that the whole mankind are facing now, namely: Batteries Disposal. It is a huge environmental issue. It was mentioned above, that though Rechargeable Batteries provide some relieve, but still, after 200...1000 (2000 at best) charge-discharge cycles they should be disposed. If you look for a totally environmental clean solution, then read the statement: 100% Environmental Clean = Muscle Power + Capacitor.
PRACTICAL EXPERIMENTS WITH GREEN ELECTRICITY
Here I would like to present the core idea in a simplified form, understandable by wider audience. For better readability I have included several pictures, which makes the whole idea pretty much self-explanatory. As you can see the experimental base is rather simple (see Fig 1...4)
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| Fig.1. Hand Crank Flashlight AKA "Pinch Flash Light") is muscle powered: it produces electricity as you squeeze it. | Fig.2. After 30 seconds of exercise you can see it glowing. |
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| Fig.3. Muscle-powered Flashlight: Transparent case provides an excellent view on internals. | Fig.4. This Hand Crank Generator was used in the experiment to produce electrical energy from hand muscles: quarters are shown to give a size estimate |
This simple hand-crank flashlight was used in the experiment to produce electrical energy from hand muscles. You can find plenty of such stuff currently available COTS (commercial-of-the-shelf), priced quite reasonably (btw, this stuff is pretty well suited for middle school the Lab works on the basics of electricity).
Light bulb was removed as it's shown on the picture. Instead, the output was connected to the rectifier (AC/DC converter) and then to the capacitor charge circuit. Eat some nutrition food (example to the left) first, then start the exercise: your goal is to pour electrical power into capacitors (to the right).
That’s it, folks! Just exercise your muscle for 5…10 minutes and this “organically” produced electricity can power LED lantern, or MP3 player, or FM/AM radio. etc. Capacitor can serve as intermediate electrical energy storage to replace the batteries in practically any portable applications.
Energy stored in capacitor (in Joules): E = 0.5 * C * V2, where C stands for the capacitance (in Farads) and V stands for Voltage (in Volts). Thus, for example, one 100F X 2.5V Capacitor fully charged stores approximately 312 J (J = W * sec)
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| Fig.5. Here we can see the starting-ending points of producing the “organic” or “green” electricity: food to the left and electrical capacitor to the right | Fig.6. Triumph of the idea: Capacitor as energy storage replacing batteries in LED lantern |
MUSCLE-POWERED CAPACITOR CHARGER CIRCUIT
Now, couple words about charger circuit (see Fig. 7 and 8). It is pretty much straightforward and understandable for any person familiar with the basics of electronics and electricity. Please notice Zener Diodes labeled Dz: it is a MUST have components, providing Capacitors over-Voltage protection. For the same purpose of over-voltage protection active components (e.g., linear voltage regulators) could be used as well. For practical example of capacitor-powered electronics read the Reference1
Fig.7. Capacitor charger circuit with voltage limiting Zener diodes
Fig.8. Dual-Capacitor Circuit with voltage balancing/limiting Zener diodes:
output voltage is doubled while equivalent
capacitance is decreased: Ceq = C1*C2 / (C1 + C2)
Alternative energy sources, like quite familiar solar, wind and more exotic ones like ocean waves, ambient mechanical vibration, etc. also could be used to produce electrical current for >charging the Capacitors. They can be used in conjunction with muscle powered generators or in any other combinations.
This idea of using "hybrid power" (new term coined to replace the original "organic electricity") in military, industrial and commercial applications is now getting more and more attention from engineering as well as business communities. Hopefully soon I will be able to provide you with more encouraging news on this topic. I see a big road ahead.
In the meantime I will welcome any efforts to support GEL Initiatives, and also would like to thank for your time and kind attention. Join the GEL Initiative now!
Regards/wishes,
Dr. Alexander Bell, NY
References
1. Alexander Bell, Single capacitor powers audio mixer EDN, Mar 1997
2. Alexander Bell. Muscle power drives battery-free electronics,
EDN, 11/21/2005
DISCLAIMER OF WARRANTY AND LIMITATION OF LIABILITY
This Document, ideas, concepts and design samples are presented for Demonstration and/or Evaluation purpose only on 'AS IS' basis without warranty of any kind. In NO CASE the Author and/or his affiliates could be held liable for any damages related to this publication.
Copyright © 2003-2009 Alexander Bell. All rights reserved