Tapping Trees for Electricity?

dr_agonfly writes "Despite many skeptics, a Massachusetts company is getting investor interest in developing a process to tap electric power from trees. MagCap is looking to boost the current power from just under 2 volts to a more useful 12 volts with investor funding." From the article: "Jim Manwell, director of the University of Massachusetts Amherst's Renewable Energy Resource Laboratory, questioned the potential of MagCap's plans. 'I'm wildly skeptical,' he said. 'I would need to see proof before I believed it. It strikes me as pretty questionable for a number of reasons.'"

The guy made an electrochemical cell ("battery")

[ClayJar]

When you hook up two dissimilar electrodes through an electrolyte (which in this case is nicely packaged within a tree and the nearby ground), you get an electrochemical potential. In the case of copper and aluminum as your electrodes, the potential is about two volts.

An easy way to get 12 volts? Connect six tree-cells in series.

Clueless Dweeb, he created a classic battery...

[nweaver]

The guy sounds like a clueless dweeb, he just created a classic battery with different anode and cathode (Al and Cu in his case, forget which would be which) in an electrolyte (the tree/dirt).

My guess is that iss no different from the classic lemon battery [hilaroad.com], just replacing the galvanized (zinc-coated) nail with an aluminum nail.

Answer to his problem

[Marxist Hacker 42]

From the article:Lagadonis said tests have generated 0.8 volts to 1.2 volts by driving an aluminum roofing nail half an inch into a tree attached to a copper water pipe driven 7 inches into the ground. But the electricity is useless because it's unstable and fluctuates.

Here's the answer: 13 aluminum roofing nails, 13 copper pipes, hooked up in series to an automotive voltage regulator and an ampmeter. If you get a fluctuation between 5-20 amps, take out the ampmeter and replace it with fuse and a cigarette lighter adapter, and plug in your iGo charger to charge your cell phone off of it.

This is how it works

[MillionthMonkey]

From the article:

Lagadonis said tests have generated 0.8 volts to 1.2 volts by driving an aluminum roofing nail half an inch into a tree attached to a copper water pipe driven 7 inches into the ground.

The real source of the power is the aluminum nail, which is converted from its oxide using electricity- massive amounts of electricity. (Remember back in 2000 when aluminum producers started reselling that electricity to California during its power crisis, instead of just making aluminum with it?)

When the nail completely corrodes, the tree will stop "producing electricity" and this company will have moved on to impressing investors with potato clocks.

Re:The guy made an electrochemical cell ("battery"

[Pedrito]

An easy way to get 12 volts? Connect six tree-cells in series.

Precisely what I was going to say, and I'm sure anyone with a basic knowledge of electricity would say the same thing.

Of course, the real problem probably isn't the voltage so much as the wattage. 12 volts is great, but if it's at about .01 milliamps, it's not going to power a whole lot. Unfortunately, the article doesn't mention amps or watts, and without at least 2 of the 3, there's not really much to say about the potential (pun sort of intended).

As Gregory Hines said in Running Scared about hitting the third rail on the subway, "it's not the volts that kill you, it's the amps". A taser hits with 50,000-150,000 volts. The reason you don't burn to a crisp when you get hit by one is the amps are so low.

You want to get the voltage to a usable level, but you also need enough amps to run whatever it is you want to run. Frankly, I doubt a tree can produce enough amps, at least without permanently damaging it, for any serious period of time. The act of being a battery will cause a chemical change in the tree which I have to think wouldn't be a healthy one. Since the tree is alive, it will probably repair the damage, but whether it can repair it fast enough to keep from dying is another question.

Needless to say, I have some serious doubts about this "technology".

No mystery - check the electrode potentials

[vik]

He has indeed made a battery, and has made a cunning choice in using an aluminium nail because of its electrode potential. It works like this:

Copper(II) electrode potential: 0.337V
Aluminium electrode potential: -1.662V

(Source http://www.ami.ac.uk/courses/topics/0157_corr/ [ami.ac.uk])

String them together in a condictive electrolyte (tree sap & humic acid in the soil will do) to get a cell with 1.999V potential - magically matching his 2.0V

Of course, his aluminium nail is corroding and will need replacing - which is where the energy comes from.

You can't connect the trees in series to increase the voltage because they share a common ground.

Vik :v)

Nothing to see here, move along.

[pla]

First of all... Increasing voltage has a trivial, known solution. Starting with DC makes it a bit harder, but still a well-understood problem with a wide array of solutions to choose from. Since none of the sources of information on this company (and I looked into this one before it hit Slashdot) mention either wattage or ampereage, I have to suspect the real problem involves not volts, but watts. Yes, magically increasing voltage would increase watts via "W=V*A", but not if you do so via a voltage conversion rather than a "real" increase in output.

Second... An aluminum nail and a copper pipe, both embedded in a slightly corrosive fluid... Hmm, where have I heard something like this before? Oh yeah, the basic galvanic battery. Sorry MagCap, the Babylonians beat you to the punch on this one.

Finally... Do trees particularly like having a few thousand aluminum nails driven into them? Not making a flakey "tree rights" argument, but rather, does using tree sap as a battery electrolyte really count as sustainable, or will it just kill the tree? Not to mention that both aluminum and copper salts tend to have deleterious effects on many organisms native to this planet.


In summary - Listen to the skeptics on this one. I'll tolerate the zero-point folks before I'll let some MBA try to sell me a massively overblown version of the "potato clock".

Step by step procedure

[GillBates0]

Step 1: Cut down said tree
Step 2: Chop into firewood sized chunks
Step 3: Burn chunks obtained from (2)
Step 4: Harness heat from (3) boil water
Step 5: Use steam generated in (4) to turn steam turbine generator
Step 5: ???
Step 6: Electricity!!!

Exactly!

[PaulBu]

Google for "potato battery", you'll find plenty like this [uiuc.edu].

I remember there was a story about some guys demoing their tiny microcontroller chip (or single-chip webserver, or something) running it off a "potato battery" to show how little power is required.

I guess I should start teaching physics to VCs, charging $300/hour -- will save them a lot in the long run... ;-)

Paul B.

Re:IPO

[AnotherBlackHat]

I think they have already proven that there is not enough sun energy per square yard of surface area on the earth to meet even a small percentage of our yearly hydrocarbon energy consumption.

Who ever told you that was wrong.

With special care, algae can produce 50 grams of oil per square meter per day.
But with more typical care, algae produces about 5 grams of oil per square meter per day.
Even using that typical figure, you could still produce the trillion gallons of oil needed annually with an area only slightly larger than the Great Sandy.

In other words, not only is there enough sun light hitting the earth, there's enough sunlight hitting in the earth in places were plants aren't currently growing.

Usefull Wattage info.

[tmortn]

According to the faq and press release on the home page for the company they do talk wattage. They essentially wire multiple taps into a capacitor circut that cleans the power a bit and ups the voltage by swapping the capcitors from parrallel for collection to series for pulsing when full.

They think they can scale the basic idea to 12 volts and 1 amp. So 12 watts of energy.

Interesting to note the faq clearly states this is not a galvanic reaction. And there is no destructive anode/electrode errosion. There seems to be no practical limit to the number of taps per tree (other than damaging the tree itself) and that the tree size dosn't make any difference. Also the power harnessed goes up during winter.

In the end it looks like it is tapping into a store of energy held universally in the ground by using the tree spike as a positive pole while the ground spike is the negative.

What I don't get is... this seems to mean it is something independent of the trees and it seems you could create an more efficient element for tapping the energy. All in all this sounds a lot like the old work of Tesla. He found that that the ground did indeed carry a charge along with the atmosphere. Heck lightning itself is indeed proof enough of the atmosphere... same for ground lightning with respects to the ground. So this isn't really all that crazy. Cloud based lightning is a difficult potential energy source to tap. However ground lightning should result from charge potentials in the gound. If you can find a way to tap that potential and release it in a measured manner you could then tap lightning as a basic source of energy. Since those potentials are driven by forces of nature it is essentially limitless.... though I suppose there is the potential to tap the energy at a higher rate than it is stored.

Re:IPO

[Kyosuke77]

I'll do one better. The best rough estimate I could find of the power transferred from the Sun to the Earth was here (link) [digital-recordings.com]. According to that we receive about 1.7x10^17 W from the Sun. Since Watts are Joules per second, we can do a little math and find that the energy total for a year comes to around 5.4x10^24 J/year. Now, the best estimate I could find for total worldwide energy consumption (link) [saving.nu] puts us at around 5.418x10^20 J/year.

What does this mean? It means the Earth receives each year from the sun, approximately ten-thousand (10000) times the energy that we consume. What this in turn means is that the sum of our methods for capturing this energy and putting it to use needs only to achieve 0.1% efficiency.

If you're going to be proclaiming something as grandiose as the statement that the sun cannot possibly deliver enough energy to earth to meet our needs, then you really should have something better to back it up. Furthermore if you're talking about something at a global scale, you should analyze it at a global scale, not a unit scale.

Re:Long way to go yet...

[Walt Dismal]

The issue is a bit more complex. There is an atmospheric potential difference on objects relative to ground. That is, there is an electric field strength in the air that increases with height. I forgot if it's 200 volts per meter, or something like that. But you can demonstrate it with a wire suspended above ground and a high input resistance voltmeter. A tree is actually immersed in an EMF because of this. Being tall, there is a significant EMF difference between crown and roots. As the tree's inside cells contain water, it is a tall conductor (well, more like a resistor). Therefore there should be some division of the EMF depending on the place you tap the tree and measure to ground. You're not going to run motors from it, but the effect is real.

Re:This is how it works

[Burz]

In some circles aluminium is more commonly known as congealed electricity.

Some companies [evionyx.com] understand this, and are beginning to make metalic (not H2) fuel cells with exceedingly high power densities using zinc or aluminum fuel.

Re:Usefull Wattage info.

[tmortn]

Ok clarification. They think a single tap can be refined to produce a useful 12 volts at 1 amp via capacitors wired in a circut. Doing some quick and dirty numbers this thing looks real if that number is accurate.

Aluminum nails are cheap, copper tubing is about a buck a foot, capacitors are pretty cheap. Just rough numbers it looks like you could wire up 1 kw worth of generating power with about 85 connections IF you had a circut capable of delivering 12 volts at one amp from a single tap. Round it to 100 for marigian of error and it looks like it is doable. Larger trees could probably stand 100 nails being driven into them if you spaced them out properly... certainly 25 per tree in a four tree setup.

This is constant power so that would be 24kw-hr's a day which is a good bit more than the average home use. Raw Materials cost would be under 1000 bucks... heck under 500. Catch would be the circut... inverter and a battery bank to deal with peak usuage, and some means of discharging of excess energy.... probably just a ground rod to sink it back into the ground.

But heck... they have already done a circut generating 2 volts. Single Tap generating around .8 volts run to 3 capacitors in parrallel which are switched to series when discharged generating 2.1 volts. They did not give an amp number on it. But if 12 volts at 1 amp is a reasonable refinement then they would have to be seeing roughly 6 amps from a 2 volt system... and they would need to be seeing roughly 15 amps from a single .8 volt connection.

Again they do state explicitly in their faq. (it is a PDF link)

http://www.magcap.com/pdf/faq.pdf [magcap.com]

"
Q: Is the voltage potential between an electrode inserted in the tree and one grounded both having different electro-potential characteristics due to electro-chemical reactions e.g. Galvanic batteries?

A: In a Galvanic reaction there is metal to metal contact. Henceforth the word "galvanized". Validation and voltage measurement does not involve metal to metal contact. In addition, a chemical reaction requires a very elevated or very low PH level in order to create this alkaline or acidic condition. Impossibility of this concept is verified by the neutral PH levels of trees. A chemical reaction requires hours if not days to manifest. Voltage per our validation occurs instantaneously upon tree tapping. Consequently, a chemical reaction would result in breakdown of the electrode and thus resulting in loss of voltage. Data collected confirms no electrode breakdown and thus no loss in voltage.
"

They also refute the possibility that the tree is simply an RF receiver due to the fact various sizes of trees used have no effect on the amount of power harnessed. This makes me wonder if you could simply drive a post into the ground and get a similar effect... or some other material with similar conductive properties to wood.

Can read the companies press release here

http://www.magcap.com/pdf/press_release.pdf [magcap.com]

Also a PDF. Much more coherent than the linked to article.

Re:IPO

[Rei]

I don't know where you got that strange (and WRONG) idea from (sorry, I had to use your words!), but the total accumulation of solar energy on the surface of the earth at midday in the tropics without clouds is 1.4kw/m^2. Most places have an average midday solar exposure of a few hundred watts per square meter. It is not midday 24/7.

What else to cover. The price of solar cells isn't the only issue like you claim, as the overall cost is mostly efficiency*cost, so efficiency must be factored in, Also important is the nature of the fixture (for example concentrators), and cells aren't the only way to harness solar power. And oil companies actually lobby relatively little compared to the size of their industry, mostly for reduced environmental regulations and for better relations with other countries (yes, they're pro-pollution, but the big oil refiners and producers are actually somewhat antiwar because you can't pump oil when guerellas are sabotaging your fields and pipelines). Their main interaction with solar is actually positive - BP and Shell are some of the world's biggest investors in solar research. There's stating to be a movement to shift from being "oil companies" to being "fuel" or "energy" companies, not limiting themselves to one particular source.