Harvesting Electricity from Wood and Water

I read this morning in Anthropocene Magazine about this study where researchers worked toward optimizing electricity harvesting from, essentially, the evaoporation of water through wood.  

In this study,

an efficient hydrovoltaic wood power generator is reported based on wood cell wall nanoengineering. A highly porous wood with cellulosic network filling the lumen is fabricated through a green, one-step treatment using sodium hydroxide to maximize the wood surface area, introduce chemical functionality, and enhance the cell wall permeability of water.

They use words and phrases like "nanoengineering" and "chemical treatment", but that should not be a deterrent to permaculturists.  Essentially, they soak a wood block in sodium hydroxide (lye brine) for 48 hours, breaking down some of the the cell wall structure, which allows the treated wood to more readily transfer water.  They then placed the resulting wood blocks in water.  The wood soaks up the water, which evaporates from the exposes wood surface above water level.  

By passing water through porous media assisted by water evaporation, a streaming current and voltage can be achieved due to the presence of an electric double layer (EDL) at the solid–liquid interface.[8] This is called the electrokinetic effect.

By adjusting the ph of the water, they further optimized electrical harvest capacity.  


source: Advancing Hydrovoltaic Energy Harvesting from Wood through Cell Wall Nanoengineering, also attached.

At this experimental stage, the researches were able to illuminate an led bulb, and power a timer with lcd screen.  They add, "the devices could also be used to charge a commercial capacitor for energy storage."



As you can see in the above video, the samples were incredibly small, and yet achieving an output greater than 1 volt.  

My low-tech homestead tinkerer brain has me thinking - these are very simple and abundant materials.  Could this be scaled up in a forgiving, affordable manner, so that homesteaders with an abundance of wood (or other cellulose-based organic byproducts) could potentially use lye to treat wood and charge batteries in, for instance, a solar rig during low-sun seasons for ecologically sound, self-sustaining supplemental electricity?

As I continue to think about this process, it occurs to me that a similar lye brine wood-soaking method is used to pasteurize woody material prior to bulk inoculation of wood substrate for bulk mushroom production.

It occurs to me that it might be possible to add the production of electricity as a process byproduct of mushroom farming.

If this were coupled (tripled?) with my proof-of-concept for mycelium insulation panels, then one could conceivably stack the following functions at a homestead scale:

*mushroom farming
*insualative building material production
*electricity production

Beau, that's pretty cool. I love lo-tech/hi-tech hybrid stuff. Thanks for the link!

Ok Beau.  You win the prize for thinking out of the box!  I admire your imagination. No telling where this development might lead.

It would be interesting to see if in a Jean Pain type of composting heating set-up you could pull some kilowatts out of the pile of wood that is being broken down. If I am following this right, that break down that produces current, also produces heat in that type of system.

Myself, I always thought a Sterling Engine coupled with a Jean Pain system might work. Use the heat from compost heat, with collected ice from the winter to get a heat differential and power a Jenny that way. But maybe this direct approach would work better?

It would have to be coupled to an inverter though and all the problems associated with that but may produce some worthwhile electricity.

A very interesting concept.

This is so cool. Has anyone heard of/experimented with the magnifying effects of old rear projector TVs? Apparently, you can take the screen and magnify the suns rays up to 2000 degrees F is the claim from one YouTube video.

I’ve never fact checked any of this, but I was wondering if that concept could be used to heat a core of some kind, or a water tank for thermal mass. Perhaps its already being done?? If you could mount the screen on something like a solar panel tracker it could potentially charge something quite large.

Here’s the link to the video. Like I said, no idea if its legit but it seems pretty cool.

Has anyone heard of/experimented with the magnifying effects of old rear projector TVs? Apparently, you can take the screen and magnify the suns rays up to 2000 degrees F is the claim from one YouTube video.

That is called a Fresnel lens. Not sure about the 2k degree claim (I tend to not believe most youtube claims) but it definitely focuses the sun and creates a lot of heat. The problem is the tracking. So far I haven't seen anything but net energy loss with those (automatic tracker) unless you have a large solar array that can power the tracker as a fraction of the PV gain. So the concept is solid and you can certainly heat water or run a sterling engine. Here's a neat article about using a Fresnel to directly create electricity. https://www.sciencedirect.com/science/article/pii/S0038092X11004129

Beau Davidson wrote:  

By passing water through porous media assisted by water evaporation, a streaming current and voltage can be achieved due to the presence of an electric double layer (EDL) at the solid–liquid interface.[8] This is called the electrokinetic effect.

By adjusting the ph of the water, they further optimized electrical harvest capacity.  

I bought a load of firewood and when it was delivered it was mostly really rotten. Hardwood firewood that was so eaten up by mushrooms that it felt like a sponge and was very lightweight. I wonder if this would be sufficient to try and generate electricity from? I just need to figure out what brine solution to use. I've got alligator clips and wires. This is fascinating.

As you can see in the above video, the samples were incredibly small, and yet achieving an output greater than 1 volt.  

Reminds me of telluric current! Telluric current is generally under a volt and that at one point remotely powered networks of telegraph repeaters.

https://www.instructables.com/DIY-1kW-MPPT-Solar-Charge-Controller/

Here's a cool (and difficult)  project that could turn that into friendlier voltages for use. The designer did a great job explaining the tech that converts these low and variable power sources into something like a nice smooth 12v

Safe tinkering!

I notice in the  40 seconds YouTube clip the charge dropped by 10 percent (or maybe even more, depending on what that actual initial voltage was). This concerns me as to the sustainability of the set-up: does the wood need replaced every 10 minutes? Was there simply not enough water? ... ? I imagine maybe the full description of the experimentation explains the drop?

I have another wondering: are standing/live trees producing electricity? Evaporation is occurring drawing water from the soil up through the trunk to needles/leaves, so is seems the same thing is already happening in every orchard and forest; one just need to figure out where to hook up the wires. (I am not trying to be a smart-ass here, this is a serious curiosity).

Hi Abe,

Welcome to Permies.

Did you do a control study with just the water alone? That would tell you the effects of the energy production contributed by the wood.

Barbara Kochan wrote:I notice in the  40 seconds YouTube clip the charge dropped by 10 percent (or maybe even more, depending on what that actual initial voltage was). This concerns me as to the sustainability of the set-up: does the wood need replaced every 10 minutes? Was there simply not enough water? ... ? I imagine maybe the full description of the experimentation explains the drop?

I have another wondering: are standing/live trees producing electricity? Evaporation is occurring drawing water from the soil up through the trunk to needles/leaves, so is seems the same thing is already happening in every orchard and forest; one just need to figure out where to hook up the wires. (I am not trying to be a smart-ass here, this is a serious curiosity).

I imagine that the video is indoors, in a lab, with relatively still air. I would think that a supply of dry, moving air would improve the production. Also, maybe heating? or vacuum? or both? would greatly boost production (I've just leaned about vacuum kilns for wood/lumber drying...). The "water"(lye solution) would probably need to be monitored and adjusted to account for the evaporation, possibly recirculating to keep it all the same (unless it needs to be in separate cells?). The exposed surfaces of the bath would ideally be minimal to reduce unwanted evaporation, and the whole setup could be optimized for space-savings.

Something like this could possibly be a closed loop, rather than rejecting the water vapor. It might also be a way to use "waste heat" from some other process, or as a regenerator within a process, and provide an electrical output... and it might not need a "lot" of heat, so that "low-grade heat" might be useful, or give a second use after "high-grade heat" got used.

Barbara Kochan wrote:I have another wondering: are standing/live trees producing electricity? Evaporation is occurring drawing water from the soil up through the trunk to needles/leaves, so is seems the same thing is already happening in every orchard and forest; one just need to figure out where to hook up the wires. (I am not trying to be a smart-ass here, this is a serious curiosity).

Yes they would (no pun intended) and by their very height.

While negligible, a small amount of electricity can be generated just by having a conductor at height. You can easily simulate this by taking a drone, attaching it to a wire, and going high with the drone. With a fluke meter attached to the wire, you can see the increasing amount of electricity produced the higher the drone flies. It is enough to power a small flywheel that will illuminate a LED light.

So it stands to reason, living trees would produce a neglectable amount of electricity as well.

If you like the idea of living trees though, you might like to consider something I always have. What if a living tree was hooked to ropes from various angles, then drawn back through pulleys and weights. As the tree sways in the wind, the sway pulls on the rope being drawn through a pulley that powers a generator. The weight on the other end then brings the rope back as the gust of wind is eased. Then as another gust hits the tree, the generator is spun again. One beauty of generators is, they produce electricity no matter how they are spun in AC configuration. In this way the living tree, from many angles so as many wind directions is caught as possible, is making power. As the generator turns, it flows to an inverter that charges batteries.

I think more electricity could be produced in that manner, without killing trees or from the production of lye tan generating current from wet decaying wood. I am not saying it is wrong, just that there may be an easier, cheaper method to glean more electricity from trees.

Man, I wonder if we could scare up the talent and resources to rustle up a project like this at this year's Permaculture Technology Jamboree.