
Thermoelectric Stoves vs. Solar Panels - MaurizioPz
https://www.lowtechmagazine.com/2020/05/thermoelectric-stoves-ditch-the-solar-panels.html
======
Animats
_2.5 kg soft pine wood per hour ... average power output of 4.2 watts_

That's 1.68wh/kg of wood.

Pine has a stored energy of about 15 million BTU/Cord (2380 lb)[1], or
4,396Kwh / 1080 kg, or 4000 wh/kg of wood. 0.04% efficiency.

That's terrible by the standards of 19th century steam engines, let alone
anything newer. It might be a way to get enough power to charge a cell phone
from a stove used for other purposes. But burning wood just to make electric
power this way is going to need a lot of forest for very little energy.

Note that the article has drawings, but not pictures, of a vacuum and scooter
being powered with a thermoelectric unit. They probably can't do that.

Thermoelectric systems are often used to power heating controls, where little
power is required. Some bigger ones can power heating fans as a backup. The
U.S. Army has a portable heater with a fan powered this way.

[1] [https://www.engineeringtoolbox.com/wood-combustion-heat-
d_37...](https://www.engineeringtoolbox.com/wood-combustion-heat-d_372.html)

~~~
makomk
Huge losses at every stage, I guess. A good chunk of the heat is going to go
right up the chimney, then most of the heat that doesn't escape is going to
directly heat the room the stove is in without going through the
thermoelectric elements, and then only a tiny fraction of the tiny fraction
that passes through them is going to get converted to electricity.

What might be better is something more like a steam engine, except without the
complicated maintenance and operation requirements and the annoying tendency
to explode if not carefully maintained. Sadly no-one seems to have been able
to design such a device.

~~~
vkou
> Sadly no-one seems to have been able to design such a device.

Why not a Stirling engine?

~~~
namibj
[https://www.microgen-engine.com/](https://www.microgen-engine.com/) seems to
be a commercial source, and
[https://www.kickstarter.com/projects/672465444/low-cost-
ster...](https://www.kickstarter.com/projects/672465444/low-cost-sterling-
engine/) was a (failed?) attempt at developing a cheap 1kW generator. The more
recent remains are in this blog: [http://volodesigns-
sterlingproject.blogspot.com/](http://volodesigns-
sterlingproject.blogspot.com/)

It looks like the Kickstarter turned into
[https://seftonmotors.com/](https://seftonmotors.com/) , which are about 2000$
for a 1.2kW (full temp, pressurized) engine.

~~~
makomk
Yeah, that's the problem - all the Sterling engine solutions end up as
expensive, exotic, low production natural gas powered devices. Which means
that you need a supply of natural gas, and at that point you have other
generation options. There was a slightly lower-power, but much more compact
and finished Australian product along the same lines a decade or so ago called
the WhisperGen which was intended to replace a hot water and heating boiler.
They ended up going out of business unfortunately.

~~~
namibj
Not sure where you're getting the nat-gas-fired idea from. The more-commercial
link I provided seems available as a micro-CHP setup, with a wood-pellet
furnace. The Melvin Package from Selfton Motors has a combined propane/wood
fire box, but the Melvin engine itself is a separate part, allowing use of a
custom heat source.

I'm not sure though why you want to burn wood on that scale. It's really
expensive to properly filter the exhaust from a wood stove, and economy of
scale doesn't hit in the kW range. I mean, yes, if you're in the middle of
nowhere, sure, but I'd claim that an install cost of 3~4$/W(electric) for the
Melvin Package, including shipping (even to a potentially-remote location,
only 100kg for the largest piece allows transport with e.g. a paramotor or two
humans, with additional trips for the cooling jacket/firebox/vents/piping) is
acceptable for a reliable wood-fueled electricity source.

------
slavik81
Traditional small wood stoves are absolutely atrocious for the environment.
Compared to an industrial-scale power plant, small wood fires don't burn as
cleanly, have fewer scrubbers on their exhaust, and are much less efficient.
Their only saving grace is that they're small, and thus the scale of the
problem is also small, but that only holds as long as they're also rare. Even
with the relatively few wood fires we have today, the effects on air quality
are noticeable:

> Toronto Public Health (2002) estimated that residential wood burning
> accounts for 11 percent of the PM2.5 found in Ontario’s air, 0.8 percent of
> the total particulate matter (TPM) and 15 percent of the VOCs.
> ([http://cleanairhamilton.ca/wood-burning/](http://cleanairhamilton.ca/wood-
> burning/))

~~~
klodolph
Came here to say this. Wood is an incredibly dirty fuel. It makes coal look as
clean as driven snow, by comparison.

~~~
abstractbarista
Looks are not everything. Wood ash isn't (nearly as?) carcinogenic.

~~~
klodolph
Wood smoke is carcinogenic. Compared to cigarette smoke, wood smoke is 12x as
carcinogenic. Of course, it depends on the wood.

------
xt00
One major annoyance of using TEG's (from my own experience) is that they need
heat to _flow_ through the TEG rather than "heat it up".. so if you don't have
a way for the heat to flow through the TEG (such as a fan or heatsink on the
opposite side of the TEG -- the "cold side"), you rapidly end up with a
situation where both sides of the TEG are roughly the same temperature and as
a result you end up generating very little power. So if the wood stove heats
up the ambient air around you, then the result is the efficiency goes down
tremendously. These things are more suited for places where you have a very
high temperature and a cold sink -- like the outside surface of a metal
chimney in your cabin in the woods type thing -- such as outside, where you
have the greatest sustainable delta T.

~~~
gkop
Silly question, but could you use one of those nifty wood stove fans [0] to
move the heat?

[0] [https://www.wayfair.com/Ecofan--UltrAir-Wood-Stove-
Fan-810CA...](https://www.wayfair.com/Ecofan--UltrAir-Wood-Stove-
Fan-810CABX-L181-K~ECFN1004.html)

~~~
energ8
The fans like this I've seen are powered by TEGs, just like the article is
talking about. So, yes, but there is a trade-off. For those familiar with ICE
engines, I'd compare it to the trade-off of a turbo/super charger.

~~~
rcxdude
They are a quite neat niche for TEGs: you have a ready supply of heat, lower
power demands, and the fact that you need to get rid of the heat on the cold
side is also what you're trying to achieve with the fan in the first place. I
don't think they will generate too much excess power though.

------
neltnerb
I just want to comment that the author for this one is a fantastic writer. At
each section I was wondering, "wait, why wouldn't you..." and it was
consistently literally the next section.

Very impressive ability to predict a reader's interpretation of what they're
saying.

But back to the article -- totally makes sense to me, as a materials scientist
with a smidge of chemical engineering, for places that already use a wood
stove for heating. I can't really imagine people redesigning gas stoves and
obviously electric stoves are a non-starter. Though a gas boiler for central
HVAC could probably generate a little bit.

Getting say 100W out of a boiler in your basement seems like a pretty minor
increase, but I suppose it does add up over time since themoelectric modules
are practically indestructible as long as you don't exceed the temperature
limits. I liked the idea of retrofitting places that already use wood stoves
to also heat water a lot though. A replacement for an existing wood heating
system makes a lot more sense if you're off the grid already (which in my
observation is often true even for US homes with wood heating).

But I love the idea of a subsidized (or unsubsidized if it's that easy)
retrofit if it brings people enough power to charge their phone and some
lights and such to get access to communication services.

~~~
acidburnNSA
The author absolutely didn't come through for me.

"Wait, isn't air pollution from wood burning as bad or worse than coal?"

"Wait, don't the carbon emissions from biofuels like wood concentrate in the
atmosphere and cause global warming even though it's technically renewable but
system dynamics matter and the fact that you can burn a log that took 20 years
to grow in an hour is a fundamental problem?"

Yeah this is a terrible idea.

~~~
lowtechmagazine
You seem not to realize that 40% of the global population IS ALREADY burning
wood as their main source of household energy use. What is your alternative
for them?

~~~
acidburnNSA
I am well aware of this. Non-combustion energy sources are what is needed if
we want to solve climate change and prevent the 3.8 million deaths per year
caused by indoor air pollution. Money spent on improving energy systems should
not be invested in infrastructure that further locks in killer+high carbon
energy sources like biofuels.

Alternatives are different in different places, but are some combo of
electrification using wind, hydro, solar, tidal, geothermal, and nuclear.

I get that these things take time. I guess if this article pointed out that
wood energy is generally terrible for air pollution and carbon reasons and
must be moved away from, I would be less upset by it.

~~~
neltnerb
I mean, that's fair, but I also think this is well enough understood as to be
obvious... maybe a comment about it would have been good for context but it
did come across as a technology article.

Of course burning wood produces more particulates, though less sulfur or
radium. These I imagine would be slightly more upscale ovens though than I
think you're talking about, the kind with chimneys so they don't exhaust into
the house at least. For those kinds of ovens I feel like demographic wise
you're talking semi off-the-grid New Hampshire rather than cooking with coal
indoors.

Consider that trees collecting solar energy are maybe 50x worse than solar
cells at converting sunlight to biomass energy. But for the kinds of
situations I'm imagining they have enough land that the wood is free anyway.
And I do believe that in that situation it's carbon neutral, except that the
carbon gets released more as soot than it started which does suck.

------
ip26
_Total system efficiency (heat + electricity) is close to 100% – no energy is
lost._

I saw this the other day. I stopped reading here. A wood stove may be nearly
100% efficient at converting wood to heat, but half the heat goes right up the
chimney. I was surprised to see lowtechmagazine skip over that.

~~~
acidburnNSA
Wait till they hear about district heating from large central power plants.

~~~
lowtechmagazine
Maybe read the article before you comment?

Here's the last two paragraphs:

A thermoelectric heating system that runs on fossil fuels also compares
favourably to a large cogeneration power plant, which captures the waste heat
of its electricity production and distributes it to individual households for
space and water heating. In a thermoelectric heating system, heat and power
are produced and consumed on-site. Unlike a central cogeneration power plant,
there's no need for an infrastructure to distribute heat and electricity. This
saves resources and avoids energy losses during transportation, which amount
to between 10 and 20% for heat distribution and between 3 and 10% (or much
more in some regions) for power distribution.

A cogeneration power plant is more energy efficient (25-40%) in turning heat
into electricity, meaning that in comparison a thermoelectric heating system
supplies a larger share of heat and a smaller share of electricity. This is
far from problematic, though, because even in Europe 80% of average household
energy use goes to space and water heating.

~~~
acidburnNSA
I read it! I meant a large central non combustion power plant with district
heating that doesn't emit air pollution or carbon. Not a biofuel cogen plant!

Yes you have to transfer the power and yes infrastructure is needed. These are
important activities in the quest for not killing people via air pollution and
stopping climate change.

~~~
lowtechmagazine
A "central non-combustion power plant that doesn't emit air pollution or
carbon"? What fuel is it running on?

~~~
tikej
Nuclear or (hopefully someday) nuclear fusion power plant.

------
chewbacha
I think the flaw here is that historically, we have quickly stripped the land
for firewood: [https://www.history.com/news/the-firewood-shortage-that-
help...](https://www.history.com/news/the-firewood-shortage-that-helped-give-
birth-to-america)

While it might be more efficient now, it's still a slightly more locally
finite than the sun is.

In addition, operating a wood stove is still a manual process that needs to be
tended to constantly, making the solar panel much easier to operate, and
likely much safer as there is no deliberate heat source in a solar array.

~~~
joshdance
Pellet stoves are almost 100% automatic. Pellets can be produced from junk
wood, and if we really wanted more wood, we could plant and harvest the
forests.

~~~
biomcgary
Unfortunately, most pellet stoves depend on electricity for the fan and
controller and stop if the power goes out.

Gravity fed pellet stoves exist but have problems with consistency (and
avoiding backdraft fires).

I've thought about building a pellet stove with an integrated Stirling engine
generator, but it's a bigger project than I have time for. It should be more
efficient than thermoelectric.

------
marsdepinski
Much better turning excess heat into steam to drive a turbine or flywheel than
this. If you have a large water tank you can store heat for days to keep a
house warm. I have 27kw cast iron wood burning fireplace and a wood/coal brick
/ ceramic kitchen and oven on the other side of the chimney. If I run both in
-10c the house gets too hot. Once heated the house needs about 4 18inch logs a
day. This is the only heating system. Burn oak, beech and birch. Burning pine
or any conifer is a disaster for your chimney. Burns like gasoline and you
have to keep feeding it.

------
fencepost
I suspect many of the folks who'd be interested in this kind of thing
(lowtechmagazine) are the same ones very concerned about climate change and
pollution. Maybe I missed it by just skimming, but is there any discussion in
there of the particulates and CO2 output of burning wood? In a very real sense
burning wood is the same thing as burning coal, minus millions of years of
pressure.

Perhaps for their next article on low-tech stoves they can investigate the
higher energy density and improved generation capabilities of coal. Why, in
some places you can even find convenient coal chutes!

~~~
tom_mellior
> In a very real sense burning wood is the same thing as burning coal, minus
> millions of years of pressure.

Burning wood only emits CO2 that was in the atmosphere recently. Regrowing an
equal size tree in the same place captures that CO2 again. This means net zero
CO2 emissions (in theory).

In comparison, you would need to plant new trees in new places (and not cut
them down) to offset the CO2 from fossil coal.

~~~
acidburnNSA
Biofuel is almost as bad as coal from a carbon emission point of view.
Lifecycle emissions are about 740 gCO₂-eq/kWh, c.f. 840 for coal (Source:
Schlomer 2014 IPCC meta-analysis). The problem is that you can burn a log that
took 20 years to accumulate carbon in 1 hour. Sure it renews, eventually. But
if lots of people do this the concentration of carbon in the atmosphere would
equilibriate at a level inconsistent with solving climate change.

And the particulate air pollution from wood is a true killer.

This concept is deeply flawed because of carbon emissions and air pollution.

~~~
tom_mellior
Agreed with all your points, I wouldn't want us to return to more burning of
wood. I was just pointing out the categorical difference to burning fossil
fuels, which even theoretically aren't part of the same life cycle and cannot
be offset in the same way -- we can't grow back forests from millions of years
ago.

~~~
7952
But they can be offset in the same way. You just plant trees. I don't see what
difference it makes if the biomass is six months old or millions of years.
What matters is the total amount of CO2 in the atmosphere.

I just don't think the idea of a "life cycle" is meaningful here. It is
similar to labelling something as "natural".

~~~
tom_mellior
> I don't see what difference it makes if the biomass is six months old or
> millions of years.

The coal in the ground isn't a snapshot of a single point in time in the past.
It represents a _succession_ of trees. Some were buried in the ground, and
others grew above them. More were buried, and more grew above. Many layers
were deposited over millions of years. The totality of coal below ground
represents a lot more trees than could ever grow at once on the surface.
Burning fossil coal puts CO2 into the atmosphere that cannot be offset in any
meaningful way by planting trees. Not on a time horizon shorter than millions
or at least thousands of years.

We would have to grow trees, then cut them down, and sequester them below
ground again in a way that keeps the carbon from escaping. Almost like, you
know... coal.

~~~
7952
The difference then is that fossil fuel + tree planting increases the total
amount of carbon above ground. But in the short term there isn't a difference
in the amount of CO2 in the atmosphere. Fossil fuel + tree planting is not a
long term solution, but neither is wood burning. And I don't think wood
burning should get a free pass just because somewhere a tree is growing.
Ideally a carbon tax would apply.

~~~
tom_mellior
> But in the short term there isn't a difference in the amount of CO2 in the
> atmosphere.

Sure. In the short term almost nothing humans do can make a difference at
Earth scale. It's a very big planet. But we have been burning huge amounts of
fossil fuels for centuries now, which has got us into trouble.

> And I don't think wood burning should get a free pass just because somewhere
> a tree is growing. Ideally a carbon tax would apply.

Agreed.

------
ekr
Funnily enough, just the other day I was thinking of a wood gas generator. It
would be interesting to see an efficiency comparison, as the wood gas
generator also gives out a lot of waste heat. The internal combustion engine
is itself not more than 25% efficient so you won't get great efficiency there
either, if you add up the losses from generating the wood gas.

But it should still be much better than these thermoelectric generators.

------
makomk
The trouble with this approach is that the thermoelectric modules are
expensive and don't generate much power compared to solar. Also, whilst the
fact that they can theoretically generate power regardless of the time of day
or the weather is nice, you're probably not going to want to run your stove
all day and produce twenty times as much heat as electricity in the middle of
a baking hot summer.

~~~
Gibbon1
Bought a van that has a secondary battery and a 2kw inverter. It'll run a
toaster, electric kettle, or a microwave no problem. Also runs a Engel Fridge
for 4 days.

Over the years I've read lots of stuff about supposed better mouse trap low
tech stoves for people the third world. I suspect what they'd rather is a
cheaply financed high tech solar powered mini-kitchen.

------
avsteele
If you do any camping or backpacking there is a great little application of
this:

[https://www.bioliteenergy.com/collections#cooking](https://www.bioliteenergy.com/collections#cooking)

This little stick burner can get a super hot fire going and boil water easily,
or grill a burger. With the electricity generated in excess of that needed for
the fan you can charge your phone/devices or use its port for an LED lamp .

That it runs on little sticks is super convenient.

------
ggm
As long as you want heat energy otherwise, why not? But if you want
electricity, and not heat, but have sunlight, I wouldn't run here. It has a
niche, as long as YOU WANT HEAT

------
jccalhoun
I remember seeing reviews of camp cooking stoves that had USB chargers.
[https://www.bioliteenergy.com/](https://www.bioliteenergy.com/) They didn't
seem to be too good at charging but, as the article says, if you are already
using a fire why not make a little electricity as well?

I grew up in a house partially heated by a wood fireplace. After hauling wood
my childhood I'm never using a wood fireplace again!

------
peter_d_sherman
>"Stick a thermoelectric module to the surface of a wood stove, and it will
produce electricity whenever the stove is used for cooking, space heating, or
water heating. In the experiments and prototypes that are described in more
detail below, the power output per module varies between 3 and 19 watts."

[...]

>"The most efficient thermoelectric stoves are those in which the cold side of
the module(s) is cooled by direct contact with a water reservoir. Water has
lower thermal resistance than air, and thus cools more effectively.
Furthermore, its temperature cannot surpass 100 degrees Celsius, which makes
module failure due to overheating less likely."

[...]

>"A much larger and more versatile thermoelectric stove with passive water
cooling was designed by French researchers, based on a large, multifunctional
mud wood stove design from Morocco. [19][22-25] They installed eight
thermoelectric modules at the bottom of a built-in 30L water storage tank,
which not only serves as the heat sink for the cold side of the generator, but
also as the domestic hot water supply for the household. Furthermore, the
stove is equipped with a self-powered electric fan and has a double combustion
chamber to increase combustion efficiency."

------
smileysteve
I was thinking about peltier heated clothes dryer the other day.

Traditional electric dryers heat to approximately 210 degrees using 240v and
about 2500 watts.

Recently, (compressor) heat pump dryers have come to the US for ventless
options.

So to produce 210 degree, 2000 watt of heat where peltiers are at least more
efficient as generating heat than resistors, seems possible with a 750
computer power supply.

~~~
londons_explore
Check your math. Peltiers get much less effective as the difference in
temperature of the hot and cold sides increases.

I imagine a drier would need a hot side ~100C (the equivalent electric
elements get red hot after all!). Peltier units with 80C of temperature
difference between the sides have very very low efficiency.

~~~
smileysteve
I always thought the low efficiency was in cooling, not in heating.

Dryer body is already acting as a heat sink for the (air-gapped) hot side and
heating interior air at 22 degree c

------
kragen
This article is full of errors, from the details up to the overall idea.

TEGs are not "more sustainable" than PV panels. As the article points out,
they're made from similar materials, using the same fabrication technologies,
except that PV panels include some plastic; and TEGs typically use exotic,
scarce semiconductors based on heavy metals, like bismuth telluride or lead
telluride, rather than abundant, cheap semiconductors like silicon. (Silicon
is too good at conducting heat to make a good TEG.) I guess Kris De Decker
just really doesn't like plastic! But a much bigger issue is that PV panels
usually last decades, except for the small minority that get smashed, while
TEGs tend to get burned up because you have to put them in a fire to make them
work, and even aside from the danger of accidental overheating (because your
water tank emptied out, say, or the air currents in your wood stove were
different from usual) the Arrhenius equation governs a wide variety of TEG and
PV failure mechanisms. So TEGs are not "more reliable".

The article argues that solar panels are not being recycled because they have
plastic in them. This is false. The truth is that solar panels are not being
recycled because almost all of them still work, even those manufactured
decades ago, and manufacturing is growing rapidly, so there is not a
sufficiently large pool of broken solar panels to supply any significant
fraction of the demand for silicon.

TEGs are not "less costly" than solar panels. Solar panels are
[https://www.solarserver.de/pv-modulpreise/](https://www.solarserver.de/pv-
modulpreise/) €0.17 per watt now.
[https://www.dx.com/p/yb3981-diy-150-c-thermoelectric-
power-g...](https://www.dx.com/p/yb3981-diy-150-c-thermoelectric-power-
generator-peltier-module-white-silver-2050639.html) is a TEG rated for 150°
which can theoretically produce about 3 watts for US$9: 15 times as expensive.
Typical PV capacity factors are around 20%†, so even if the TEG got a 100%
capacity factor — which it won't, since you don't have a constant 3-watt load
to hang off it — it would be three times _more_ costly. (Is there a cheaper
source for TEGs somewhere?) This also tends to show that more energy and
materials are needed to manufacture TEGs than equivalent solar panels, since
that's what most of your money goes to buy.

(150° is about the limit for bismuth-telluride TEGs — bismuth alloys and
intermetallics tend to melt at low temperatures. It is not true that, as the
article says, that "the hot side of bismuth telluride modules withstands
continuous temperatures of 150 to 350 degrees", nor are Bi₂Te₃ modules "the
most efficient ones".)

The article argues that TEGs are "100% efficient" because any energy not
harvested by the TEG is used to heat your house. Aside from this being
undesirable in the summer — a significant concern for many of us here in the
"global south" that Kris De Decker pretends to care about, from his apartment
in Spain — it's also the case that burning up kilowatts of precious energy
directly into low-grade heat is an extremely inefficient way to heat your
house. The apartment I'm in here is primarily heated by an air conditioner
with the capability of functioning backwards, in which mode it produces about
3 kilowatts of heating in exchange for a single kilowatt of electricity, for
300% "efficiency". (This is not a violation of thermodynamics; the Carnot
cycle is reversible, and the indoor and outdoor temperatures just aren't that
far apart.) Producing the same amount of heating with the oven or a wood stove
would waste two kilowatts of gas or wood.

Additionally, wood stoves are seriously fucking bad for your health. They
produce massive amounts of carcinogenic smoke.

TEGs do have real merits — I've loved them since I was a kid. They can provide
_small_ amounts of power, at _very low_ efficiency, in a totally autonomous,
independent, and portable way. You might be able to charge your phone, run a
reading light, or trickle-charge a battery. But they are not an alternative
power source for your house. They are not going to run your vacuum cleaner or
your e-scooter, contrary to the misleading illustrations in this article. A
normal household vacuum cleaner needs 500–2000 watts, and at 5% efficiency
that would mean running 10 to 40 kilowatts of heat through your TEG, a power
level at which you will quickly cease to appreciate the space heating effect.
However, as John Nagle pointed out in
[https://news.ycombinator.com/item?id=23356206](https://news.ycombinator.com/item?id=23356206),
the end-to-end efficiency in the Lebanese study cited was not 5% but 0.04%,
because most of the energy in the fuel goes right out the chimney, and most of
the rest goes directly into the house, not through the TEG.

So what could have motivated such a mendacious article? Did Low Tech Magazine
get an advertorial contract, similar to The Atlantic's famous _David Miscavige
Leads Scientology to Another Banner Year_ deal? Does Kris De Decker simply
have no interest in whether what he's writing is true or false, scraping
together whatever argument he thinks he can trick people into believing in
order to support his preconceived conclusion? Either way, this article
destroys the credibility of Low Tech Magazine. (Unless it's a false-flag
operation? Maybe someone is impersonating Kris De Decker to discredit him?)

† In polar countries like Germany, the Netherlands, or England, PV capacity
factors may worsen to 10%. Near the Arctic or Antarctic Circle things are even
worse, and within them of course you can't use solar power without a seasonal
energy store, which is totally impractical for most uses.

~~~
lowtechmagazine
You have completely misunderstood the article. Try reading it again with an
open mind.

~~~
rcxdude
Seems like a reasonable rebuttal so me. Care to say something more substantive
about how it's based on a misunderstanding?

~~~
lowtechmagazine
Why would I repeat what is already written in the article?

------
thescriptkiddie
Randall Munroe (xkcd) did a video [0] a while back to promote his book "How
To" where he addressed several (mostly silly) ways of powering a hypothetical
home using only energy gathered on-site. In it, he calculated that 0.2 acres
of trees only produces about 38 watts of usable power, if you burn them to
generate electricity at the same rate they grow.

[0]
[https://www.youtube.com/watch?v=j1tcyEo2tQk](https://www.youtube.com/watch?v=j1tcyEo2tQk)

~~~
slavik81
I look forward to reading about Christopher Robin's adventures in the 19
Kilowatt Wood.

