Turquoise Energy News #162
2021 (Posted December 4th 2021)
Lawnhill BC Canada - by Craig Carmichael
Feature: Efficient, Quiet, Low-Speed
("Savonius" flavor) "Wind Wall" Windplant for Light to High Winds
(Project Summaries etc.)
- Wind Wall: New design has it all: low noise, high
(40%?), power in low winds, bird grille, to be made of abundant
recycled PP plastic. - New Grid Tie Solar Inverters - Handheld Bandsaw
Mill Kit Status - At Last:
A Superior way to fasten magnets to an axial flux rotor!
(Miscellaneous topics, editorial comments & opinionated rants)
- Grass Building Insulation (R4.2 per inch) - Smol
Thots - ESD
Transport - Electric Hubcap Motor Systems
* "Low Rolling Resistance Tires" -- So Called? -- An Adverse Report
& Electric Equipment Projects (no reports)
* "Wind Wall" with New "Savonius" Rotor Design, Vanes, "Darrieus"
level performance, even in low winds
- "Wind Jammer" rotors - Mini Wind Tunnel - better flat "air
scoops" rotor - new "compound rotor" design better yet - These
plus stationary wind guide "vanes" improve performance to "Darrieus"
levels: around 40% instead of under 20%.
* My Solar Power System:
- New Grid Tie Solar Inverters: One installed
- Power Outage and "Off-Grid" System Improvements
Solar Production log et cetera - Monthly Summaries and
November in Brief
I've shown views of the broad beach below my
home at low tide before.
This time I thought I'd try for high tide in a storm with a new moon,
5th. (Drying foam says I missed highest tide by a 1/2 an hour or so.)
Big logs were rolling and
tossing around. Surely there is power in waves!
It's nice to know that in all the inflation
some things have been getting cheaper:
Solar PV, Wind and maybe Geothermal power.
(When I was a kid in Edmonton, CH4 "natural" gas was dirt cheap. Now
out of the
former permafrost in the Arctic, but in Europe the winter heating
supply is in question.
But it was never "sustainable".)
Early in the month I had a short vision one night
featuring my warmest winter jackets, then snow. I figured it must be
serious for it to have been brought up. Gosh, could it be it would it
even be hard to get from the house to the far firewood shed? It was
that in Victoria in 1996.
I have a large hallway closet with plywood walls intended
for firewood. I don't like to keep firewood in the house and had used
it for general storage instead, but I emptied it of its riffraff and
filled it with the wood from part of my new firewood shed, carrying it
up in bulk in a trailer behind the lawn tractor.
About a week later the forecast was for snow all across
Canada & USA, and there was snow in some places. On the 9th some
news said even North Africa was getting a dusting of it. I suspect that
the highway will be impassable for a time. Are we going to have long
power outages going along with this? It seems more than possible around
here. By the end of the month nothing special had happened in Northern
BC. (It did start snowing on the evening of December 1st with more the
next day. Still not unusual.)
Oh, there was one thing: on the 8th there was a strong
wind and the power failed. Trees often fall across the power lines in
storms. Nothing special in that either, but I tried a few "off grid"
things out - running the freezer and the microwave, and monitoring
power and the little charging the DC system was capable of in dark
clouds - and I planned some improvements to my solar systems,
especially DPDT switches to make it simple to switch solar panels from
the grid tie inverters to the DC power system. This plan was rudely
interrupted before I got anything much done by the following:
VAWT (Vertical Axis Wind Turbine) - the Wind Wall
The month was proceeding smoothly when on the 10th Kamil
dropped by with an idea for making a windplant from a fishing float. I
think much of it but I had just seen in youtube suggestions the idea of
a "Wind Wall", a frame with rotors on the inside. An artist had started
it, I believe, with rotors linked together that formed pretty patterns
as they turned. Then Robert Murray-Smith had made one filled with small
Savonius rotors connected to small generators in a compartment below.
We watched the video.
Robert Murray-Smith's Wind
Wall - from his video
(I also found a gigantic megawatts "wind wall" computer concept set on
pillars over the sea, which seemed totally unrealistic. If it had at
least been floating it could have aimed itself into the wind.)
I said winds usually blew straight up my driveway from the
ocean so my "wind wall"
didn't need to turn to get most of the wind, and Perry had the great
idea to mount the unit on
the gate, right in the best wind, but thus it would swing out of the
with the gate for cars.
Of course I had some ideas of my own tucked away in the back of my
mind too, and I thought again after the power failure of how little
solar power there is here in the winter. So somehow I got sucked into
this new project, unwanted and
seemingly not very promising in the big picture. I made a tall,
thin Savonius rotor (why a bunch of short ones?) and stood it in front
of my big box fan. Of course it turned, more or less.
Then I cut it
down to half the height and I made a mini wind tunnel: a box the size
of the fan from
scraps of plywood,
open at both ends. I put a bearing in a hole at the bottom and drilled
a hole for the shaft to stick through at the top. Every rotor tested
would then be mounted in exactly the same place relative to the fan and
I measured the Savonius rotor at 80 RPM. I also measured
wind speed in the tunnel with the fan on "high" as 3.1 meters/second,
which is a little below where most propeller and Darrieus windplants
even start turning. So I was testing for the more frequent case of
light winds instead of rare storms.
"Light winds capable" was the target - a few tens of
watts often instead of hundreds of watts rarely.
Then I thought
I'd search on line and see if there was anything better. I found a
paper that mentioned a "slightly better" shape and had a diagram of it.
I printed the diagram. "Full page" was just the right size for the
plastic PVC pipe I was using. I heated the pipe in the oven and bent it
to the right shape to fit on the pieces of wood I cut by cutting out
and tracing the drawing. It turned at 82 RPM. But the first rotor was
only 7 inches diameter while the new one was 10 inches, so the same RPM
actually represented considerably more outer rim speed and more power.
(With the black cable tie on the shaft you can count the
"R"s. On the left top is an "M" meter. You can't find RPM without an
"R" counter and an "M" meter. Luckily it didn't get too fast to
count "R"s by eye for 30 seconds.)
thought, the new shape was flat both on the back (the main part of the
advantage) and the front - a disadvantage. The front would have more
air resistance returning upwind to the "top" of the power cycle. I
added a second layer (screwed on alium. sheets) that made it a rounded
front face again, which created a further improved "Savonius" rotor
that turned at 90 RPM. That seemed rather thrilling. How much - or was
it how little - creative thought had been given to Savonius rotor
shapes in the last 100 years or so?
The profile now had "thickness", like an airplane wing
with a different top surface shape than the bottom. I have never seen
that for a "Savonius" type rotor before.
Next I put a
stationary vane in to direct the wind toward the side of the rotor
being pushed downwind, and away from the side pushing its way back
upwind. This also concentrated the wind and increased its speed. This
time the rotor hit 160 RPM, and took some actual bit of force pinching
the shaft to slow it down much. Potential tens of watts, I think. With
a couple of vanes it hit 172 RPM. The vanes would of course be built
into the frame of the wind wall. (Further testing might optimize vane
sizes, placements and shapes, but even one flat board works wonders!)
occupied only about 10 days. I made a somewhat
long and rambling video Evolution of a Windplant
and put it on Youtube:
The Hayes Hybrid Rotor
Setup. U of Utah wind tunnel
The actual subject of the same
paper was about making and testing a hybrid rotor,
where the Savonius bottom half was the means to start the Darrieus top
half spinning, even in low winds, thus harvesting power with something
toward the efficiency of a Darrieus rotor (~40%) at catching the wind's
energy. (Straight blade Darrieus rotors only work once they are
spinning, so they need some way to start them.)
Up to this point doing this had also become my idea.
However, it seems a typical "good" Savonius rotor is about 18-20%
efficient. The first better shape should thus have been over 20%. My
third shape then was surely at least 25%. When I added the vane and
nearly doubled the RPM, I felt I must have achieved at least similar
efficiency to the Darrieus type, around 40%, with the improved Savonius
type of rotor and the vane.
So then!, why would I make a Darrieus or hybrid rotor at
Since the "wind jammer" types turn a little slower than the wind speed
instead of 4-6 times faster, they will surely be far quieter.
there was nothing more that needed to be developed. No figuring out the
best Darrieus shapes and configuration, or how to make the optimum
hybrid to get best performance out of both parts of the rotor. An
improved "Savonius" "wind wall" with vanes had it all!
A viable "Wind Wall"
product would be worth selling, and I started thinking seriously about
how to produce them on at least a limited production basis - probably
formed out of recycled polypropylene fish nets, which have been
collected off beaches here recently, representing thousands of pounds
of free material.
The tricky part would be the electric generators
themselves. My "Improved Piggott Alternators" would be great, but
overkill. (except maybe in a hurricane!) I ordered some small
generators from China, but the speed will probably have to be geared up
higher for them - that's noise and inefficiency. Flat or poly-V belts
are supposed to be highly efficient and might work well, with little
There was another rotor shape variation I wanted to try.
It would be a simplification if a single sheet rotor surface could be
used. I tried it on December 1st. It didn't work as well. I think, like
the airplane wing, I have discovered the basic best profile in the
"compound" rotor and future profiles are likely to be variations on
this essential theme.
I also got an oven from the refuse station, to put the
molds into to melt the PP into the desired shapes. I intend to cut off
the back and make it a much deeper insulated oven box, so that it will
molds at least 5 feet long. It is 23 inches wide. (I'll use it outside
the laundry room and run the 230V power cord from the dryer plug out
through the window.) The idea of an oven large enough to hold any mold
make, and using the fishnets that only have to be cut to fit in the
of shredded, should revolutionize the way I can make
flat-ish plastic components. But for starters I'll just use the oven
as-is and make first the rotor molds that will fit into it. (Or I may
just open the windows and use my kitchen oven for the first one or two.)
Then I'll have to try making the alium. molds and actually
molding the plastic in them. (The PP plastic won't stick to alium. once
I intend that they'll be a bottom "box" piece with sides to hold the
plastic, and a top "lid" piece that fits just inside it. Then I'll have
clamps with springs that push the lid down into the box, and as the
melts, the springs will push them more and more closed until the
plastic is solid with no air gaps, and it won't compress any farther.
The thickness will be controlled by weighing the plastic before putting
it in. (If necessary there can be end stops that stop further
compaction together of the pieces at the desired thickness. These may
be in the mold, or adjustable "end stop" bolts on the clamps.)
New Grid Tie Solar Inverters
I didn't have
enough grid ties for all the solar panels in summer sun, and I wasn't
happy with the way the present ones kept jumping back to zero and only
gradually ramping up again when a cloud came along. By the time they
were back to full power, another cloud would come and it would start
all over again. So when I ordered 3 new grid ties they were a different
brand, 700 watts rated.
At long last they arrived on the 29. On the last
day of the month I replaced the one in the cabin with a new one to see
what improvement there might be. Soon after the cord to the cabin came
unplugged and so it was off all day. The next day snow covered
the panels, and they were still half covered on the 4th. Well, at some
point I'll be able to compare them and see if the improvement is 2% or
Handheld Bandsaw Mill Kit Status
On the 19th I took the mill to Wayne to take and send pictures to the
engineer. Then I typed up the notes I had made when I was sawing and
sent them along with the CAD drawings of the plates.
In the meantime the stainless steel plates had been
waterjet cut and were mailed to me. The price was rather shocking for
such a small, simple job, and made me all the more determined to get
the CNC table and the HHO torch running in order to be able to do such
things for myself.
At Last: A Superior way to fasten magnets to an axial flux rotor!
Eureka! After repeatedly thinking about this problem since
2008, I woke up on December 4th with a better answer. The problem of
course is the centrifugal forces on the magnets on a spinning rotor. I
epoxy them on, and I have sometimes wrapped them with PP webbing and
epoxied that on. But I have had glued-on magnets fly off rotors with
force when a motor gets spinning too fast. And I've had them come off
commercial motors, too (a lawnmower motor and my lawn tractor starter
motor). A few months ago I came up
with the idea to drill holes in the rotor so 'plugs' of epoxy reach
through to the other side to help hold, and also epoxying half way up
the sides of the magnets.
Now it occurs to me that the best and also easiest thing
would be to rough
up the surface of the rotor with an angle grinder where each magnet is
to sit - maybe even dig in some grooves. There's just about no way the
epoxy could lose its grip on all those rough surfaces.
Then similarly rough up the underside of each magnet, even
going through the protective layers. Once it's epoxied onto the rotor
it's protected again.
To be even more sure one would apply the epoxy also around
sides, which would ooze down before it sets and become a thick skin
around the magnet
where it meets the rotor. Roughing up the sides of the magnets a bit
along with the bottom might be a good idea too. So might a second coat
once the first has set.
I have previously broken rectangular magnets loose from my
twisting them with a 15 inch crescent wrench. With such a technique as
this, I could see the whole magnet breaking into fragments as one
twisted, without the epoxy ever breaking off. I would think the large
rotors for the
planned unipolar Electric Hubcap motor should be good for about 3000
RPM instead of 2000, or 2500 as I was more opimisticly hoping for! That
will mean it can be geared down that much more and have 1.2 to 1.5
times more torque and power at a given vehicle speed. or that the top
vehicle speed can be raised that much.
If I ever finally get to making the motors, they're going
to be really great ones!
(Miscellaneous topics, editorial comments & opinionated rants)
Missed the Eelgrass
Excited by hearing that eelgrass makes great building
insulation and thinking of my cabin, on the 3rd I walked almost to the
far end of the beach looking for some, a couple of kilometers(?), and
there were some small drifts of it near the far end, high up on the
beach and in a spot I could park the utility trailer near. I thought
I'd grab it the next day before the tides got too high and it was
washed away at high tide. But I miscalculated. The 4th was in fact the
day of the new moon and hence highest tides per fortnight, and I
arrived with car and trailer and Perry almost at high tide. Also it was
stormy and there were big waves washing in. We managed to get 3
wheelbarrow loads into the trailer before the water got too high for
comfort and even the highest-up eelgrass started washing away before
our eyes. Not much of a load! Anyway there was a lot of kelp in it too,
and perhaps it would best be used as mulch on the garden. Some big
piles washed in later, closer to home, but by then I didn't want it.
Forget the Eelgrass... How About Lawn Grass?
up eelgrass, I went farther and looked at
just grass grass. Sure enough, a company is processing that into batts
for insulation, too. The "R" value is around 4.26 per inch, which is
27% better than fiberglass. (~3.3. I never did get an exact figure for
eelgrass - perhaps 3.5?) That would mean R 15 in
a "2 by 4" wall (actually 3.5 inch) and R 23.5 in a "2 by 6" wall (5.5
inch). With such an improvement, might we return to making "2 by 4"
walls as was done up until... hmm, 1980 or so, was it? Around that time
exterior walls started being made of 2 by 6es to get a higher "R" value
than R12 with fiberglass.
processing does it need? Those making it
were first "de-juicing" it to extract "the cellulose". Their pictures
were pretty tiny, but to me the batts looked
like they were made of bits of straw, so I suspect the process wasn't
very involved and that simply drying it would do almost the same. Then
they added jute and PETE. It was said the PETE could be replaced by
PLA. Starch was also mentioned, and borate. (More info:
I can cut grass from the lawn any time during the summer!
(There's a bagger for the lawn tractor that I've never used but
certainly could. With luck I can even dry it.)
I started to think that something similar might be
accomplished by installing grass between wall studs or ceiling rafters
and then spraying it with something. Or maybe make a horizontal form,
lay the grass in it and spray it to make batts? The spray substance
would be expected to bind the grass into a matt or batt, and to provide
anti-flame and anti-mildew properties. But does it need to be made
"less green" by adding plasticiser or anything at all?
If the wall is dry it shouldn't rot. And does it even need
to be "fireproof"? A gyproc wall with grass insulation would surely be
far better fire protection than the cedar board walls with fiberglass
insulation in my garage! (Now there's scary construction for
fire safety, and which has been bothering me since I bought the house!)
The safety is in the gyproc, also in the alium. exterior of my cabin.
It would be hard for a fire to get into the wall. I could do small
fiberglass areas around potential sources of heat: electrical boxes and
hot water pipes.
I looked on line. Gyproc is
considered an adequate thermal
barrier for flammable "spray foam" insulation. So it should likewise be
considered sufficient for grass even if flammable.
I think maybe I'll try that: raw but fully dried grass for
cabin wall insulation. Not in the ceiling with open rafters to be sure,
but in the outer walls with gyproc and alium protection. That would cut
the need for fiberglass way down and provide better insulation.
Cellulose Fiber Insulation
To continue with the
topic, I've mentioned eelgrass and grass grass building insulation. In
a more "conventional" vein, did you know that compared to fiberglass
insulation, recycled cellulose fiber insulation has a higher "R" value
per inch, isn't itchy to install (but is dusty), doesn't attract pests,
rot or mold, is cheaper and has better fire retardant properties. The
explanation for this last rather unintuitive feature is that when a
fire reaches the inside of a wall, fiberglass will shrivel away from a
flame, allowing it to spread into the cavity. Cellulose fiber
doesn't and as loose fill it fills the entire cavity, and so the flame
has to char it bit by bit to get into the wall.
This was in fact tested by building 3 identical "large
outhouses". One had no insulation, one had fiberglass, and the third
cellulose fiber. All three were lit on fire at the same time. The
uninsulated one burned down in (I am going by memory and rounding off)
40 minutes, the fiberglass one in about 60 minutes and the cellulose
fiber one in 80. I was impressed. The video is on youtube somewhere.
(Could grass be better than one might expect, too?)
* On the 21st, big news. My friend Tom
phoned and said there was no food - or gasoline - in Victoria (BC). He
was probably exaggerating, but there was petrol rationing, and a week
later he sent a picture of big
empty shelves in Wallmart there. This sort of trouble has been coming
on for years with overpopulation, the economic disenfranchisement of
the public at
large, the increasingly wild weather destroying crops and manifold
But exactly how and when it would and will unfold, the
actual events in any given area, are bound to be a surprise. With the
most common weather word lately in play, "unprecedented" rains and
flooding created washouts on all the major highways in and out of
Vancouver/"the lower mainland" of BC along with the rail lines and fuel
pipeline. This is or was also BC's biggest farm and food belt. Since
Vancouver Island's transportation and supplies also come through the
lower mainland, Victoria and the whole island is also cut off. Tom's
family has only a
month's food on hand, and they are doubtless more prepared than most. I
trust essentials will be restored within a month - for now - but the
roads is severe, and more heavy rain savaged repair and recovery work.
* Other parts of the world are having their own troubles. China's
industrial northeast, already short of fuel, has had severe blizzards
and so have many parts of the Northern hemisphere. There was even snow
in Tunisia (and Texas again), and more floods in Soggy Arabia - and
places in South America where in the past it has rarely and lightly
rained. And I'm sure I've left a few things and places out.
* Presently things are still fine in the BC North. Highway 16
(and I believe a rail line) is still open to Alberta and the East,
where many of our supplies come from. The ferry to Haida Gwaii is still
running. But one can also visualize many "not unlikely" problems that
could close long, thin arteries through the mountains. The highway from
Prince George to Prince Rupert is often closed owing to mudslides or
But "Dairyland" is in the lower mainland and "Island
Farms" is in Victoria, and as I have lamented before about the laws
eliminating local dairy farming, there are almost no dairy cows
anywhere else. It is inevitable that that if North-South
transportation is virtually cut, or the dairy farms or plants are too
flooded out, northern BC will surely soon have no milk
from those drowned cows in Abbotsford - not for many months if ever.
(So far no problems at the groceries here, but grocery stores on the
mainland have been shopped out by people stocking up.)
* Africa continues to have by far the lowest rates of Covid in the
world and a far lower death rate from it. Most African nations don't
lock people down or shut down their economies or force citizens to wear
masks, and have no money
for vaccines, hospital treatments, and so on. But lots of Africans get
enough vitamin D (from sunshine) to be more resistant to viruses, and
outdoors in the warmth a lot. Their buildings probably don't have
recirculating air to spread whatever someone breathes out to the rest
building. Plus Africans tend to be younger, and Covid is mainly harmful
in proportion to age. They also have ready access to free or low cost
Ivermectin and hydroxychloroquine owing to the presence of a multitude
of parasitic infections endemic to that continent. It seems all these
things add up to "no Covid".
But why are the rest of us not being advised about getting
sufficient vitamin D to ward off cancer and Covid virus? Why do we not
have Ivermectin and hydroxychloroquine "over the counter" in our drug
stores? Why are we so often being told to stay indoors instead of
getting out in the healthy outdoors? Why are we being told to wear
masks after they have been demonstrated in studies to be
virtually ineffective? What happened to "follow the science"? And why
is any of it "government edicts" instead of "medical advice"?
* The new "omicron" (AKA "moronic") variety of Covid discovered in
South Africa appears to have already been in many other places around
the world - it was just identified there first. However, it seems it is
very mild, with just "feeling really tired" for a couple of days, no
hospital admissions and no deaths.
* It is said that government governs by the consent of the governed. I
saw a new "declaration?" going around on the internet: "Withdrawal of
consent to be governed by [your] government. [fill in the name of the
government - your nation, your province or state, ... Signed by - you.]
If a few people fill out such a declaration, they are
probably flakes. If millions do, when it becomes a considerable portion
of the population, the legitimacy of that government is probably in
serious question and if it is incapable of meaningful change,
alternatives to the "status quo" should be diligently sought after.
* Michael Dowd has a great two-part video set on youtube, "Collapse in
a Nutshell" and "Overshoot in a Nutshell" - both subtitled
Our Predicament". He defines a "predicament" as a situation incabable
of solution that one must live with and adjust to. As it is much too
late to prevent severe climate and earth changes, it is a "predicament"
rather than a "problem".
Whenever a civilization starts to degrade its
environment, when nature can't renew and keep up with what is being
done, it is in "overshoot". Without managing its population to maintain
a sustainable level and taking
immediate corrective actions at the first appearance of environmental
overshoot, that civilization is doomed to collapse.
population will continue to grow and the environment will become more
and more degraded, more and more rapidly, until vital resources have
been fully expended and the civilization collapses with great loss of
Dowd quotes someone as saying "Civilizations start with a forest and
end with a desert."
* I was surprised to learn that in the last 4000 years, at least 88
civilizations - that all thought they were "eternal" if they gave it
any thought at all - have arisen, thrived for 200-400 years, overshot
and ruined their environments with too large a population, and quickly
afallen. Only when our ambitions to espouse the root values of
being human and humane, to be fair and considerate to all for today and
for the grandchildrens' grandchildren into the indefinite future,
become embedded into our culture and
way of living, will we learn how to create sustainable societies.
[reminder? 7corevalues.org ]
* Globally we have entered "overshoot", and with the advances in
technology many global "tipping points" of environmental and ecological
nature are already behind us and the consequences can't be avoided. We
will have to live and die with them. Some would pinpoint 1974 as the
year we started going too far, when we started using resources faster
than nature was replenishing them. I would put it about a decade
Dowd points to charts of things that go "hockey stick" - suddenly
rising up -
Dowd's two 1/2 hour videos are well worth watching!
(Eccentric Silliness Department)
* The kitchen cabinet place manufactured several items, but most of
their efforts were counter productive.
* Their installers guaranteed their jobs to be "counterfit".
* Pharmaceutical school adage: "A patient cured is a customer lost."
* They call it a golf "tee", obviously meaning "T". But isn't it really
more of a "Y"? (or is it?)
* Last year my vision was 20-20. This year it's only 20-21.
* Bagger, beggar, bigger, bogger, bugger... Which word is out of place?
Answer: D. All of the above. None of them have anything to
do with each other, although I'm not sure what a "bogger" is.
* "Find" is the present tense of "found". But it is claimed that Samuel
de Champlain "founded" Quebec. Since "ed" makes a verb past tense, the
present tense must be "found". So on his way up the St. Lawrence
Champlain says, "Here I found Quebec." But if he found it, it must have
already been there to find. So how could he be the founder? Somewhere
it doesn't make logical sense... I've foundered!
"in depth reports" for
each project are below. I hope they may be useful to anyone who wants
to get into a similar project, to glean ideas for how something
might be done, as well as things that might have been tried, or just
of and not tried... and even of how not to do something - why
work or proved impractical. Sometimes they set out inventive thoughts
almost as they occur - and are the actual organization and elaboration
in writing of those thoughts. They are thus partly a diary and are not
extensively proof-read for literary perfection, consistency,
completeness and elimination of duplications before
publication. I hope they may add to the body of wisdom for other
researchers and developers to help them find more productive paths and
avoid potential pitfalls and dead ends.
"Low Rolling Resistance Tires" -- So
Called? -- A Report
In the summer I was very pleased with my new Bridgestone
Ecopia low rolling resistance tires. But when the temperatures started
dropping to 12 or 15°C or below - typical for 3/4 of the year -
they turned into werewolves. Rolling resistance shot up like a rocket.
Instead of say 1.2 to 1.3 kilometers for each percent of battery usage
at 80 KmPH highway speeds, it
dropped to maybe .9 or so - a 25 to 30% drop.
Instead of hitting town with 82% battery as I had in the
summer, it was more like 72%, more percent drop than kilometers driven!
And instead of getting home from there with 56-61% battery remaining,
it was down often to barely over 40%. To drive to Port Clements and
without hitting the low battery warning at 20% - or perhaps even
if I was careless - I had to drive the highways at about 55 to 70 KmPH
instead of 80+. I don't think it's ever been that bad before. So it's
taking much longer to do that
drive, and with pulling over to let others pass. It's well that the
highway is less than busy, but it doesn't give electric cars a good rap!
I went from being very happy to wishing I hadn't said I
didn't want to keep the old "Ironman all season" tires. Very
disappointing! They dropped in the winter too (which was why I wanted
to try something different in the first place), but not as badly as the
"Ecopias" did. 1.0 to 1.05 kilometers per percent of battery drop
seemed to be typical in colder weather, but not under 1.0 except in
I must conclude that the people giving the glowing
reports on the Ecopias must live in California or other warm
weather climate zones.
Then it got colder. At 2° the performance actually
seemed to improve, sometimes - to about what the old tires did. Now if
temperatures around here weren't usually in between.
Interesting... in the last few days, I've twice gone out
to the car
(plugged in) and found the heat on! I've never seen that before. So it does
do preheat - but
when it wants to, not when I do.
Other "Green" & Electric Equipment Projects
HHO Gas Torch
[4th] In a video 'Rulof Fai da
Te' (Italian, = "Rulof DIY" AKA 'Rulof Maker') showed making an HHO
and torch using 3 cylinders of water. In this one could blow into one
through a tube and pressurize the water, making a fiercer flame. Much
was visual but I'm sure I missed some details in his Italian
presentation. He showed quickly cutting through some can - I think it
was a steel spray can.
Raising the HHO gas pressure, or perhaps instead adding
air or excess oxygen into the torch flame, might be a perfect thing to
do for cutting thicker steel. For adding oxygen, instead of costly
welders' tanks, one might make a water hydrolyser that separates the
oxygen from the hydrogen and discard the hydrogen?
(Conversely, if one was say trying to melt down copper or
silver, extra hydrogen could be used instead, to make it a
Either way one would need a two input torch to mix in the
extra gas. I just ordered a one-input one. Oops!
[10th & 11th - Rememberance day! "The
Great War", "WW I", "The War to End All Wars", ended 103 years ago this
month. I'll bet that no one alive today ever met and would remember
anyone who died in that war.]
that day the frost and damp started to get to it.)
I had just seen a couple of
"wind wall" titles as youtube "suggestions". I hadn't watched the
videos, but the idea seemed intriguing somehow. One by Robert
Murray-Smith had several Savonius rotors beside each other on a common
frame. In a sense each rotor was a separate windplant. I thought it
might be less unwieldy than a big propeller, especially with the frame
around the outside. One could put a screen or grille over the front and
rear to keep the birds out. (wouldn't want their bodies - or nests -
jamming the rotors, after all!)
Furthermore, one could extend the frame front and rear
with wood at angles to form a square sort of venturi duct, speeding up
the wind where it hit the rotors and hence providing more power in
lower winds - as I have wanted to try for some time. (The difficulty of
the compound curves for a round propeller windplant venturi kept me
from making one. A square venturi would be much easier!) Furthermore,
individual "slats" could deflect air from the "wrong" sides of each
rotor to the desired side, a good way to increase the effectiveness of
most "VAWT" windplants. Thus each rotor column could have its own
venturi section within the outer venturi, easily attached to the outer
frame at top and bottom.
Kamil, living "off grid" and wanting wind power, came over
and knowing nothing of my thoughts showed me a fishing float he had
found, and said "If we cut it Here and Here and heat the plastic and
twist it, and do that all around, it could be a wind turbine. I didn't
really think much of the idea per se. OTOH I am distressed at the tiny
amount of solar on bad days in winter here in the north compared to the
minimum daily needs for the house, and so I started thinking... (oh,
no, not thinking!)
We watched a couple of the videos. "Stepper motors" were
mentioned as generators. I had some. (I'm not convinced they're very
good for that application, but they're a start.)
There were objections that the wall (in spite of being
made up of multiple VAWTs) was aimed in one direction. I said the wind
usually came off the water at Kamil's, and at my place it usually
blasts straight up the driveway, and so it wouldn't need to pivot.
Perry said then it (mine) could be mounted on the driveway gate. That
seemed brilliant. The gate was in almost the right place for maximum
wind, and it would all swing out of the way for cars to pass.
I decided to build a roughly one square meter wind wall.
If it was good but insufficient, one could add more wall sections.
took 4 of the 8 pieces of PVC pipe that had made up my previous VAWT,
sitting unused outside the door of the shop all this time, unscrewed
them from the wood and put them in the oven. The oven always turns
itself to 350°F, and I casually just left it there. It was much too
hot. Except for the first one I pulled out, the pieces bubbled up,
turned a brownish color and stank up the house. (What was I using
before... 250°F?) Then they took much to long to cool and harden
again - back to their original 1/2 round shape, and I had to trade
simple leather gloves for oven mitts to hold them against the cylinder.
(And nothing cured the fact that I had originally bought pipe with
holes in it.)
[12th] I made a template of two overlapping circles with a compass for
the simplest Savonius windplant rotor, then cut one out of plywood. I
traced out 4 more from that and made the first column for the wall -
two sets of rotors set at 90° from each other. I didn't see any
good reason for making 6 short rotors in each column. It seemed to me
that that was just more, smaller parts that would catch the same amount
I figured I'd have the motors (generators) in a housing at
the top, pointing down, and simple bearings at the bottom. Hopefully
rain and salty spray would leave the motors alone and drip down on
cheap bearings instead. Another change would be to have each pair of
rotor columns counter-rotating WRT each other. having them all going
the same way means the air columns are "fighting" each other instead of
reinforcing, and would require twice as many, thinner, inner "venturi"
[13th] I also wondered whether the simple semi-circle "Savonius" rotors
were anything like as efficient as they could be. Why not find one with
"the best" profile? I did a web search for "most efficient Savonius
rotor". The first thing that became apparent was that most of them had
a substantially smaller overlap between "buckets" than my 50% (which
somehow I thought I remembered as being "typical" from long ago).
Then I ran across a paper
by T. Letcher of trials done at Ohio State University, titled Small
Scale Wind Turbines Optimized for Low Wind Speeds. (Undated but
with references as late as 2009) It specificly aimed to create a
smaller VAWT design that would be the most efficient at low wind
speeds. The Savonius was the sure starter in low winds, but the
Darrieus is more effective, harvesting up to 40% of the passing wind's
energy instead of 19%. So they made a hybrid: the bottom half was a two
piece Savonius and the top half was a 3-blade Darrieus. (So ~30%
It seemed to me that getting near 30% of the wind's power
with half being of each rotor type, and optimized for low wind speeds,
was a goal more worth aiming at rather than just getting 18-20% with
all Savoniuses, and I studied the paper in detail.
"In for a penny, in for a pound!" So much for keeping it
The discussion continued with a couple of variations of
Savonius and mention of another "slightly" more efficient one with a
different "bucket" shape (than a split pipe). They didn't make it
because "it would have been hard to produce". It didn't look hard to
me. The "buckets" were the same shape as I had made previously in my
earlier designs. I tried it for the next rotor(s).
They rejected the idea of directing the air onto the right
sides of the rotors and away from the wrong sides to improve
performance, because such directors would have to be aimed depending on
the wind direction. In this 'wind wall' idea I'll use it because it'll
be simple and when there's a good wind it's usually coming straight up
my driveway from the east southeast.
Then they moved on to the Darrieus rotors on the same
shaft. They tried out three airfoil shapes, two symmetrical and ending
with the asymmetrical "S2027". They tried 3", 4.5" and 6" blade widths.
It's easy to see why an unsymmetrical blade will work better: The
blades go around in a circle, not in a straight line, so the curved
blade is the one cutting straight through the air. Indeed the 6"
symmetrical blades performed poorly in the small diameter rotor. They
would be "plowing" through a lot of air.
The team also tried (or at least mentioned) different
blade angles. Since the blade angle does a complete circle as the rotor
does, I don't expect the angle relative to the direction of travel
makes a large difference, and they only showed results for in-line
They also tried different diameters to set the blades at.
This is not only important relative to blade width and overall wind
cross section to sweep, but as a relationship between the Darrieus
blades which perform best going faster than the wind speed, and the
Savonius rotors which perform best at a little under the wind speed. If
the Darrieus diameter is double that of the Savonius on the same shaft,
and the Savonius is going 3/4 of the wind speed, the Darius blades will
be going 1.5 x. Hmm... on looking up a general rotor performance chart,
the Darrieus should be turning around 6 times the windspeed to extract
maximum energy! That suggests that it should be 6 times the diameter of
the Savonius? I hadn't realized it was so high. That's certainly not
how their unit looks, and a 48 inch diameter rotor sure distorts the
thin 'wind wall' idea! The funny thing is, in their report they charted
better performance setting the blades at 12" diameter than 14".
Let's see... other graphs show Darrieus peak performance
as being at 4 x or 5 x wind speed instead of 6, and all show steep drop
offs on either side of "optimum". Is 4 x for three blades and 6 x for
two? Then what's 5x for? What to believe? Of course, the width of the
blades must be a factor in the best RPM, as well as the number of
blades. It's about catching more wind and letting less slip past
unused. Certainly more blades sweeps it all at a lower RPM, and the
Letcher group only tried a 3 blade design. Presumably 6 blades would
cut the best blade speed, and hence the diameter to best match the
Savonius, in half? Darrieus rotors of twice the diameter of the
Savonius rotors would be more in keeping with the small diameter rotors
desired for the wind wall. Too bad the Letcher group didn't try more
blades. They said they couldn't find any information on advantages of
different numbers of blades. Apparently they didn't consider that they
should try to match optimal speeds with the Savonius in their own
hybrid rotor. I suspect they would have got better results by adding
more. (Although again they got better results with 12" diameter
Darrieus than 14", which doesn't seem to fit the theory. OTOH, both
diameters should have been way under "optimal". As they didn't mention
the diameter of their Savonius, the "ideal" diameter of the Darrieus
can't be exactly calculated.)
But the proportions and with just three blades would seem
to indicate a mistake in the design. Either the Savonius is being
over-revved by the Darrieus and hence is a drag rather than a
contributor, or the Darrieus is being held way under its good producing
speed, or both. But perhaps I may be using "conventional" logic that
works at higher wind speeds? Their unit is intended to work well in low
wind speeds. Also, they got the best results with 4.5 inch blades
rather than 3 inch (or 6 inch), so maybe the relatively "fat" blades
compensated for the smaller number. All these variables!
I think I'll try having the Darrieus rotor double the
diameter of the Savonius, but with 4 to 6 thinner blades instead of 3
fatter ones. My first Savonius is 7 inches, so the Darrieus should be
around 14. (I wonder how far I want to go in trying variations myself
without having a wind tunnel for reliable comparisons between them?
Hmm... I must remember I do have a good anemometer... and a fan!)
After getting some performance graphs in a wind tunnel,
they looked up typical wind speeds for 4 Ohio cities and compared
expected performance against a commercial "Windspire" 20 foot tall
Darrieus VAWT. In all cases, at the expected wind speeds over a year,
the hybrid design at just 12 feet tall produced substantially more
power - from 69% to 177% more. (I'm leaving out one city where they
calculated 707% more - apparently owing to very low present production!)
Finally, not thinking very highly of using stepper motors
as generators, I spent 80$ and ordered four small 20W DC generators for
4 columns in the wind wall. (With larger diameter Darrieus rotors,
there certainly wouldn't be 6 rotor columns in a meter long 'wind
wall', which would also take on more of a 3D aspect with substantial
thickness from front to back.)
But I expect to turn every second hybrid rotor upside-down
so the wider Darrieus rotors overlap each other, top, bottom, top,
bottom. Thus the width of the wall will be two wider Darrieuses plus
two narrower Savoniuses. rather than four wider Darrieuses with gaps
between the Savoniuses.
[15th] I tried holding the double Savonius I had made in front of my
big square 3-speed fan. At top fan speed it turned lazily around, and
sped up a bit. At 20 inches square it wasn't as tall as the rotor, but
if the rotors were all to be just half height, about 17 inches, it was
big enough. So I had at least one option for testing each rotor under
similar low wind conditions.
[16th] "In for a penny, in
for a pound..." I went out to the shop (Brr - freezing out!) and made a
plywood box with open ends to blow the fan into. That strengthened the
air flow and made a mini wind tunnel with fairly "linear" air flow to
allow better comparisons of different diameter rotors. I put a hole to
mount a bearing at the bottom and another at the top to stick a shaft
through. That was convenient and also ensured that every rotor would be
in the same place for every test.
Then I cut my
Savonius rotor down to size (2 * 8.5 inches tall) and mounted it in the
"wind tunnel". It turned about 60 RPM on high fan, 30 on medium, and
came to a stop on low. (At that rate I won't need anything except a
clock with seconds to measure RPM!)
What else was needed? A
variable load with watt readings, the anemometer, and and RPM counter.
To get an adjustable load I could use a DC to DC universal converter,
feed a power resistor through a power monitor, and adjust the voltage
or the maximum current limiting of the converter until the rotor was
outputting the most watts it was able to (which would be unit watts, if
not fractions of a watt), and measure the RPM. Ooops, and a generator.
Hum ta tum...
That way I could try a few different things, and adjust
until the Savonius and the Darrieus rotors gave their highest power at
the same RPM. (Since they'll be tested separately I would start the
Darrieus rotors with a hand spin.)
[17th] I formed pieces of
the plastic into the "scoop" shape for the "a little more efficient"
Savonius(?) rotor. This time I set the oven to 250°F and got better
results - no burning the PVC plastic. I printed out the template from
the Letcher document. "Print to fill page" in "Landscape" mode printed
it just the right size for the 4 inch pipes, 10 inches end to end. I
cut it out and traced it on wood, then cut the four wooden end pieces
and screwed the rotors together.
It was visually, intuitively obvious that although made of
virtually the same materials and the same size, the shapes would make
them far superior. And if one couldn't form their blades, they were
just 1/4 of a round of pipe and a flat piece of about the same width.
Nothing in that seems "hard to make".
In the evening I finished by drilling holes in the wood
pieces for a 3/8 inch shaft, and put it together. The free-spinning
rotor results were a little better than just lazily, almost barely,
turning. It was just more energetic all around. Here is a table of the
(with no rotor
in wind tunnel)
with rotor spinning
|2nd "FLAT SCOOPS"
|2.1 (8) 
|3.0 (11) 
|3.6 (13) 
Air speed was measured at the distance of the rotor axis
from the fan. The point of the highest steady speed reading was
recorded. A second anemometer gave virtually the same readings as the
first. Even the highest speed is pretty slow, as typical windplant
cut-in speed is around 4 meters per second. (But it sure felt
breezy sitting in front of it - I'd have thought it was more! Maybe
because the shop was so cold?) Of course a plant designed for low wind
speed will give more power on more days. One designed for high winds
will have great output on the few days per year when there are storms.
With the second rotor air was measured right beside the
rotor on the side going upwind, the right side. I thought it was
interesting that it was higher than the airspeed with no rotor in the
tunnel. On the left side, the speeds were lower.
RPM was taken after steady speed was attained, by counting
turns over 30 seconds and doubling the number. (...counted each time
the black cable tie went by the clock.) The outermost diameter of the
old rotor was 7 inches, and the new one spun faster in spite of being
wider: 10 inches diameter. Doubtless I should have spaced the "air
scoops" on the old one father apart with less overlap, but I have no
doubt that the new shape "scoops" is better.
Now I don't understand why anyone ging to the trouble of
making a wind plant would make the "two half barrels" shape instead of
the newer one. Even if you can't form the "scoops" into the shape you
want at will (plastic too big for oven?), they are simply 1/4 to 1/3 of
a circle plus a similar area flat section, which could be made in two
If the Darrieus rotor is to be twice the diameter of the
Savonius, that'll be 20 inches. That will certainly tax my 22 inch wide
wind tunnel. (And make for a fat "Wind Wall"!)
[18th] The trouble with giving thought to a subject is that thoughts
lead to more thoughts, which lead to more things that should be tried
out. So far I had been been looking at "flat" shapes, shapes with a
one-dimensional cross section that can be made from a single flat sheet
of material. And that's all I can remember seeing anywhere for "wind
jammer" rotors. The new scoop shape is doubtless better at "scooping"
the wind when going downwind, but it does make an area of flat
leading surface facing into the wind for part of the rotation, and the
most counterproductive part of Savonius operation is the adverse torque
of the rotor returning upwind. Here the flat profile must have more
drag than the semicircles. But the shape of the leading surface could
be different from the trailing surface, giving the rotor cross section
a volume. This would be analogous to an airplane wing, which has a
different upper surface shape than the underside. This could be
accomplished by using two shaped flat sheets, such as adding
something like this (thin lines - two variations) to the upwind section:
Thus it has the "scoop" profile when the wind is pushing it, and a
"rounded" profile when it's pushing up through the wind to the front
side again. This might even give it better "airplane wing" lift to pull
it forward through some parts of the rotation.
The fact that the profile must be considered through
360° of rotation makes consideration of what the best shape should
be - and surely there must be an "optimum" compromise shape -
complicated. (It took decades after Savonius before someone even came
up with the center gap idea, and still later (1990) the better "scoops"
shape instead of "half buckets".)
Perhaps there's some means for computer modeling at many
angles of attack and finding what it might be, but I'm going to have to
go with my intuition and sense of proportion. I didn't want to glue a
piece of PVC to the original PVC in case I wanted to change it. I
wanted something easily reshaped and reattached for at least a few
trials. I had some thin aluminum sheets. They could easily be cut and
bent, and screwed onto the plastic rotors.
I did the bottom two and tried it out. The free spinning
RPM seemed entirely unchanged.
Okay, how fast was it turning compared to the wind speed?
Radius is 5 inches or .125 meters. Should sweep the circumference each
turn: 2 * π * .125 = .785 meters per turn. Windspeed 3.1 m/s. If the
outside of the rotor was going the wind speed, it should turn 2.58
turns per second: 154 RPM. 82 RPM is 1.37 turns per second. So even
free-spinning it was only turning half the speed of the wind. Much of
this could be bearing friction, but not all. (RPMs seemed to go up as
the month went on. Perhaps the spinning shaft was gradually smoothing
out the hole in the plywood?)
upper section of rotor was more in the center of the tunnel and its
airflow. In spite of the disappointing performance so far I decided to
try "compositing" the upper one as well. This time there was
improvement in no-load RPM, especially with the fan on "High". The
decreasingly improved figures on "Medium" and "Low" probably result
from increased friction from the increased weight of the rotors.
Friction rules much on "low" and "medium" - and doubtless still even on
"high". It would have been nice to turn the fan up another notch or
two, but it didn't have it.
no rotor in
(OD = 7")
|2nd "FLAT SCOOPS"
If a regular "overlapping semicircles" Savonius rotor is
18-20% efficient per some charts and figures, then an improved "scoops"
profile rotor is surely at least 20% efficient. The "composite" shape
was clearly better than either - perhaps around 25%, then? With this it
seem I have indeed made a better "wind jammer"/Savonius rotor. Well, I
don't seem to embark on these sorts of projects without ending up
somewhere, in some way, advancing the "state of the art".
BTW First Rotor Retry: I couldn't find the video of the first
rotor spinning. Perhaps the camera wasn't actually recording when I
thought it was. I reassembled it (ie, with the axle) into the wind
and ran it again for the camera. To my surprise it visibly spun faster
than the first time. The friction must have been reduced somewhere in
there since the first tests. (I had put in some oil. Also the two
piece shaft can be crooked if not screwed together far enough at the
coupling nut. That would cause increased friction.) I checked the RPM
and put the new figures in the table above. On the first try I read 84
RPM. On subsequent tests it seemed to be around 76. Notwithstanding
that it hit about the same RPM as rotor #2 on "High", with a diameter
of 7 inches instead
of 10 that's lower linear "tip speeds" at the outer rim. And at lower
fan speeds it slowed down more than the newer rotors, indicating that
as expected it had less torque to overcome friction - or to drive a
generator. (At least it turned - barely - on "Low" this time) Power is
torque times speed, so it was quite obviously less powerful.
I could rebuild the first rotor re-setting the "buckets"
with less overlap, diameter 8 or 9 inches overall instead of 7. The
figures might be interesting and somewhat better, but they obviously
wouldn't equal the new design, so I'll probably skip it. The 2nd
"scoops" rotors are 10 inches with the same amount of plastic and wood,
and the 3rd rotors are the "scoops" with the more streamlined
"bucket-ish" front edge added to provide the best advantages of both
the others, so they're bound to be better. I'd rather experiment with
proportions and placements, if I do, on the ones that are actually
proving by comparison that they are better than any existing "Savonius"
[20th] More scary thoughts... To progress further along these lines,
rotors could be made with moving parts that shift to more optimum
orientations depending on what part of the rotation they are in. For
instance, what if sections "p" (ref. drawing above) were hinged at the
inner end, and could swing back maybe 20 or 30° when going upwind?
Air would spill behind toward the "q" area, giving it lowered
resistance to moving upwind. But that gets complicated to make, and
will probably have a noise penalty when moving parts bang shut. Not to
mention they'd probably be a maintenance nightmare.
Instead, next it seemed more logical to try vanes to get
the "venturi" effect to increase the airspeed and better direct it onto
the rotors. That would reduce the drag on the rotor returning upwind by
deflecting the wind from in front of it - probably an even greater
improvement. "Vanes" or "venturis" is disagreeable in principle to many
as the rotor no longer will accept wind equally from any direction. But
for the "wind wall" it is assumed there is a prevailing wind direction
which covers most good winds, or perhaps that the whole wall can be
re-oriented (with a steering vane - or simply by hand?) to face the
present wind direction. I put a single 7" wide flat plywood vane at
that would deflect the wind normally buffeting the returning side, and
aim it toward the power stroke side. It almost touched the
rotors with the inner end maybe 2" to the right of center (with
rotor going counterclockwise). Anything that pushes more air per second
through the rotor on the power stroke greatly improves performance. And
for vertical rotors, appropriate deflection also reduces the load
against the sections returning upwind. The no-load 160 RPM result
more than worthwhile:
no rotor in
ROTOR no load RPM:
(OD = 7")
|2nd "FLAT SCOOPS"
ROTOR no-load RPM
no load RPM
WITH WIND DEFLECTOR VANE no-load RPM
(/try 2, 21st)
|80 / 104
|120 / 138
|160 / 166
A "typical windplants(?)" graph on the left
shows 15(?)% efficiency at capturing the wind's energy for Savonius
rotors, but the U of Utah paper said it was 18-20% and their own unit
(bottom section in picture below) hit 19%.
And it shows best Darrieus speed as 6x wind speed, but in the graph on
the right optimum is clearly 4x.
Perhaps this is a difference between 2 and 3 blade models?
For the first time I could
feel a pretty significant pinch on the shaft was needed to slow the
little 10" * 19" area rotor pair, so that it would be capable of
a few watts - maybe even tens of watts - in a low wind. If the #3
composite rotor was capturing 25% of
the wind's energy, then with the vane it must surely be 35 to
45%. 40% is the efficiency figure commonly given for a Darrieus rotor.
A Darrieus rotor with a deflector vane might achieve
better than 40%,
perhaps even 50%, but at this point I'm thinking I've attained the
efficiency range with a 'low wind speeds' suitable rotor also more
suited to the "wind wall" idea, and that I should drop the Darrieus
part of the plan entirely. It is superfluous! And blades turning much
faster than the wind speed are bound to be noisy (and more
trouble-prone WRT maintenance - and in storms). The whole 'wind
wall' idea with the 'slightly under wind speed' rotors will be much
more acceptable to potential users. The whole next area of R & D
for the project has magicly been eliminated, owing to the unexpectedly
effective achievements in the first area!
The Hayes/T. Letcher/Ohio State University,
hybrid Darrieus/Savonius windplant.
From what started as a pretty casual project, I
engaged in what turned out to be a step-by-step development of a
superior "Savonius" type
windplant - one that would be actually worth producing to sell for
off-grid power. Of course it is scalable to any reasonable size. The
humdrum project actually became exciting!
I tried moving the deflector vane around but only days
later found a spot slightly better than its original position, which
gave 160 RPM. ("/try 2", on the 21st, above)
But was there also an optimum shape for the
deflector vane? "Flat" works - obviously quite well - but surely
"optimum" is something more like the profile of a venturi front
opening. And then there's adding a second vane, and vanes on the
downwind side. Not tonight! How close to the Betz limit of capturing
58% of the wind's power could one actually come by optimizing this idea?
What has occurred to me tonight is that one might adopt
the idea of having the magnets spinning on a disk(s) at the top or
bottom of the rotor, with stationary iron-free coils next to that
sending off the electricity. No gears, belts, friction or noise, ultra
high generator efficiency.
Later it occurred to me that the optimum vane shape might
be modified as a compromise to better accept wind from, say, 30° to
either side of straight on, since even "prevailing" wind direction can
vary. The rotors will probably turn with wind from most any direction
in spite of vanes, but we do want a range of the most common wind
angles where the power is greatly enhanced by them.
[21st] If I added a vane on the downwind side similar to the one
upwind, the wall would be bidirectional. The wind could come from
either face. Oh, wait... the downwind one would be counterproductive,
creating low pressure just where high was needed and vice versa. It
should in fact aim the other way. Hmm... So much for "bidirectional"!
I tried placing a downwind vane in various positions but
didn't get more than a very few more RPM out of it - if any. Going back
calculations of the 18th, it would seem it was already spinning as fast
as the wind... but that was the un-accelerated wind speed. But might it
have more potential torque, even if the speed wasn't much more?
With the downwind vanes adding so little, at night I had a
new idea. Instead of the "venturi", the vanes should concentrate the
wind but also direct it around into a counterclockwise vortex to push
the vanes' rotation along as much as possible. Here is the idea as a
diagram (clockwise rotor instead of counterclockwise):
I tried putting in a second vane in various places, which
maxed it out at 172-174 RPM but after I tried moving it I never got
quite such a good result again.
[22nd] At this point I decided I had something and I decided to write
something up for a funding proposal as an "any infrastructure
improvement". Along with making the wind wall I proposed to make the
rotors out of recycled polypropylene fishnets. I finished it as a
"preliminary proposal" the next day, printed it out, and took it in to
"Community Futures". I didn't mention money, only that it was a "game
changer" for wind power with the most important technical details and
some of the same photos and performance charts as here. [25th] I talked
to the director, Mike. It appeared they might be
more interested in it if it was already in production, or very close to
it. (What else is new? Nobody funds the "D" in R & D.)
Well, what do I really need to get to that point? A means
to produce everything. Some of the things are simpler than others. What
do I need to produce rotors, wind guide vanes... and perhaps the outer
frame parts? I need to melt down PP fishnets in molds to turn them into
solid plastic parts.
Rather than make complex molds with heaters in them, I
would rather just make simple molds and heat a whole space with the
mold inside it. So first I need a heater big enough to hold any or all
the molds. If I make the parts small enough to fit into a kitchen oven,
then I just need an oven from the refuse station rather than to create
a special heater. And a long cord to the dryer plug inside.
My own oven is about 2 feet wide. But some pieces of the
outer frame will need to be at least 4 feet long or so. Maybe even 5
feet? Probably the simplest thing would be to make a kitchen oven box
very deep by ripping the back off and extending it back to 5.5 feet
long with sheet steel. I could put extra legs at the back, and wrap it
in rock wool insulation. Same oven door, same thermostat and heater
(It also occurs to me that if it'll hold pieces long
enough and about 2 feet wide, I could also use it for my other project
idea of making transparent greenhouse wall & roof panels from
recycled transparent plastic - PP, PS or PETE. That would again be much
simpler than my previous idea of making a press mold with heaters built
Okay, so an oven for all heating. Then molds for all the
frame and rotor parts and pieces? Probably, nearly everything could be
made from the recycled PP!
Starting from the inside with the rotors, two 2-piece
alium. molds for the trailing and leading faces are required. I got the
4 foot by 8 foot piece of
alium. I've been wanting from Steve, and I can probably have him do any
welding they might need. The
molds will need some way to press the two faces together. Perhaps some
metal "spring clamps", that will continue to squeeze the plastic as it
melts until the mold is compressed to the desired thickness? In fact,
that sounds about right for all the parts. For these large pieces,
melting down un-shredded fishnet for plastic, that's surely simpler
than big vats for melting the plastic and pressing it into injection
I'll try doing rotor molds that will fit in my kitchen
oven first, and make sure a few rotors work out well before hauling
home an oven, extending it, and making the larger molds for the big
All assuming I'm actually going to tackle the
project at all. But there's revenue and even "export" (from Haida
Gwaii) potential! It's all part of the "off grid infrastructure"
[Still 25th] I had been shooting video of the various rotors and then
the vanes, and late in the evening I made a video and uploaded it to
youtube. It might generate some interest, or at least it'll show people
some new and improved wind technology.
My video "Evolution of a Windplant": https://youtu.be/S8c06FUBrpg
[29th] Interesting... on a whim I started the fan and checked the RPM
of rotor #3 with no vane, and got 104 RPM. then 106. Nothing changed...
what happened to 90 RPM?
I noted that in the "scoops" design the gap at the center
is "up-down" while the Savonius is "left-right" with no "up-down" gap.
I wondered what would happen if one made the Savonius design but with
"up-down" gap instead? Has anyone ever tried that? If it worked as well
as the "scoops", it would also be simpler
to make the "from a single sheet" shape.
[Dec 1st] I made this profile (#4) and tried it out. It spun about 102
RPM, just about the same as #3 at 104 RPM. But #3 is 10 inches across,
and the new one is only 8.5 inches, so the same RPM represents lower
outside edge speed and lower power. The compound faces shape (#3)
The four rotor profiles tried: L - #1, Original
Savonius with half-circle edges all ending along a line.
R - New profiles, #2 with plastic scoops only, #3 same with rounded
leading faces (metal) added on.
Center - #4, Savonius "half circles" with gap more like #2 & #3. It
wasn't as good.
Have I attained the
ultimate "Savonius" type rotor shape? I seems to be better than
anything else anyone has come up with. I note that if I insert flat
sections inside the #4 "half barrels" it could be shaped very similar
to #3 and would surely spin faster. Perhaps like airplane wing and
propeller profiles it's the basic best, and so future profiles are
likely to be variations of the theme. I'm happy. It's time to move on
development of other aspects of the wind wall and then production.
As a footnote, I'm not the only one to notice wind
directing vanes significantly improves performance. Here is an
"omnidirectional" unit with six stationary wind-aiming vanes by Alex
Erauw (Youtube - he called them "AVP"), that greatly improved
performance of several of his VAWT rotors.
With the wind wall one or two(?) vanes can be tailored
optimally to the prevailing wind direction.
His RPM performance chart. Great
("AVP" ...something Vortex something...)
New Grid Tie Solar Inverters
Why? I had noticed that the Y-Solar grid tie inverters,
while reliable enough, would stop producing whenever the light level
quickly dropped by a noticeable amount owing to clouds, and take tens
of seconds to ramp up from zero to max again. By then the next cloud
would come along.
They were okay in a completely clear sky, but we rarely get those here.
Far too often I would look at the meters and see and they were be busy
ramping up from zero again instead of producing full power. How much
energy was I missing out on? Plus I didn't
have enough inverters to handle all the solar panels in summer
sunlight, so I wanted another one or two more anyway.
I ordered 3 new 700 watt grid tie inverters, model
GM1700/120VAC for 18 to 50 volt DC solar panels.
[30th] These having arrived on the 29th, I swapped out the one on the
Cabin system in the morning. I noted that it read about 55 watts before
I disconnected the old one, but it took the better part of an hour to
hook up the new one. (Wiring mistake - had to redo: +/- swapped - ouch!
don't know if it's protected against reverse polarity or if there just
wasn't enough daylight to fry it. Anyway the unit was okay.) After
connection to the AC line it waited 3 seconds to ensure the AC was
and then ramped up in a second or two to 108 watts. Too bad it was too
long between readings to compare them. The output stayed pretty steady
compared to the Y-Solar inverters, which jump up and down more.
A month or two of operation should show whether or not
there's a notable improvement in overall production.
Power Outage and "Off-Grid" System Improvements
[8th] at around 7PM in high winds and storm, the power went off. It was
out (except for a 5 or 10 minute reprieve midday) until 4PM the next
day - about 21 hours. I had lots of light in the livingroom with a 12V,
.2 or 6 watt COB light I made a while back as well as a 36 volt, 12 by
24 inch ceiling light panel, which I had just made a cord with a 10 ohm
resistor for the previous day, with which it drew 13 watts and gave
lots of light. (The panels' rating with their AC power adapter is 24
watts. I have now bought 12 the same, specificly because in addition to
being fabulous lights, they work nicely at 36 volts DC. A 5 ohm
resistor at 39 volts makes it about 20-25 watts.) The computers and
internet being off, I did some reading off printed pages - a book, and
later reorganized much of the chaos that was my electronics lab by
adding a big set of shelves.
Even by bedtime, the ice cream in the freezer was notably
softer. In the morning [9th], not knowing how much longer it would be
out, I thought I should start running the fridge and freezer.
First I unplugged the old yellow set of lithium iron
phosphate batteries on the garage floor ("100 amp-hours" but some of
the cells are really less), and plugged the house DC into the Sprint
car instead (240 amp-hours). Everything is 36 volts. Then I got out a
36VDC to 120VAC inverter and plugged it in to the high current
porcelain "T-plug" socket under the kitchen sink, and an extension
cord, which I ran to the freezer in the hallway. I ran it for an hour
on that, an hour on the kitchen fridge (135W with inverter) and an hour
on the garage freezer(also 135W), then pretty much repeated the
process, watching that the fridge didn't turn its "430W freezer coil
defrost heater" on.
Once I had this started, I connected the charging also to
the car. Then I disconnected one solar panel from a grid tie inverter
and added it to the DC system. The charging in the cloudy weather went
from 44 watts to 88. Then I tried to add the two panels on the pole,
but nothing changed. There was no voltage coming from them. On fixing a
bad connection they brought the charging up a little more. But the day
was cloudy and the sun low, and only a few times did the charging
roughly match the drain from the fridge.
Only when running my small freezer (80W with the inverter)
in the afternoon did the charging start to catch up with the drain from
Once again, this practice run showed serious deficiencies
of my system for "off-grid" operation of the house. This time, the
biggest one was the solar panels being mostly connected to the grid tie
inverters, so they weren't helping to keep the batteries up. I decided
to put in DPDT switches so that all the panels could tie into either
the grid ties or the DC system, individually or in pairs.
The second one was that running one appliance at a time
and switching them manually won't go very far without being a nuisance
and probably often neglected. It doesn't take an unwatched freezer too
long to thaw the things stored inside and ruin them. Running at least
two items requires two inverters, and three would be better. Three
would also require another circuit from the 'solar garage' into the
Another consideration is the total power usage. If an
extended outage does occur in the cloudy winter with low sun, the
kitchen fridge is the one to 'abandon' first, as it uses the most
power, and quite a lot (430W) when doing a defrost cycle. It would be
better to use the smaller freezer as a chest refrigerator by turning
its temperature control to above freezing, and have one fewer
appliances to feed. (I'll need to use up some frozen groceries before
It would be good to have another power source besides
solar - one that didn't use gasoline. What besides wind? After the
power came back on, I got sidetracked by the wind power project and
hardly gave another thought to adding switches on the solar panels or
any other improvements.
Daily/Monthly/Yearly Log of Solar
Power Generated [and grid power consumed]
(All times are in PST: clock 48 minutes ahead of sun, not PDT which
is an hour and 48 minutes ahead. (DC) battery system power output
readings are reset to zero
daily (often just for LED lights, occasionally used with other loads:
Electric car, inverters in power outages or other 36V loads), while the
grid tied readings are cumulative.)
Solar: House, Trailer, (DC@house) => total KWH [grid power
meter reading(s)@time] Sky conditions
Km = electric car drove distance, then car was charged.
31st 2384.71, 1073.69, .09 => 5.89 [88134@17:30] Sunny
with haze at times
01st 2386.58, 1074.72, .00 => 2.90 [88170@16:00] not bad
2nd 2386.96, 1074.89, .14 => 0.69 [50Km; 88225@19:00]
Wind & rain, dark.
03rd 2389.42, 1076.20, .00 => 3.77 [88257@17:30] Much nicer.
04th 2389.89, 1076.39, .14 => 0.80 [88291@17:30] Rain
05th 2391.23, 1077.03, .14 => 2.12 [85Km; 88342@19:30] Sunny
AM with storm, rain & blah.
Oops!?! (1/2 of 2 days)
3.13 [55Km] quite a bit of sun
07th 2395.22, 1079.16, .15 => 3.14 [88420@17:30] Mostly sunny
(6.27KWH over 2 days: 3.13 + 3.14)
08th 2395.45, 1079.18, .00 => 0.25 [88469@19:00] Storm - wind, rain,
09th 2395.47, 1079.21, .54 => 0.59 [88477@17:30] Grid power was off.
Mostly cloudy. Ran fridge & freezers from DC system with inverters.
10th 2397.43, 1080.62, .41 => 3.78 [55Km; 88516@17:00] Some sun
11th 2397.56, 1080.70, .11 => 0.32 [88572@17:30] Dark and windy
12th 2399.11, 1081.54, .15 => 2.54 [90Km; 88620@18:30] Some sun,
13th 2399.67, 1081.82, .09 => 0.93 [55Km; 88668@16:30] I've seen
14th 2401.78, 1083.00, .11 => 3.40 [88702@16:00] Mostly sunny except
for the rain.
15th 2403.53, 1084.04, .10 => 2.89 [88753@17:00] It snew a bit.
16th 2404.23, 1084.69, .10 => 1.45 [55Km; 88801@18:00] 0° ? low
17th 2405.45, 1085.26, .02 => 1.81 [88850@17:30] 9° ? high
18th 2406.37, 1085.83, .58 => 2.07 [88892@17:00; 55Km] "Longest
eclipse of the moon in 600 years." (11:19PM to 2:43AM IIRC) The clouds
had the decency to part a couple of times so I could see it. Also
several telescopes were following it live on youtube.
19th 2407.40, 1086.44, .64 => 2.28 [90Km; 88944@17:00]
20th 2407.63, 1086.58, .17 => 0.54 [90Km; 89001@17:30] Why did the
DC system charge up another KWH+? The PowMr charge controller lost its
settings somehow and decided it was charging lead-acid batteries to 3 *
14.4 volts = 43.2 volts. If it had got that far, it would have been bad
news, maybe even fire or explosion. Luckily it only got to 41V, under
the 42V limit. Not to be trusted, these charge controllers! Isn't there
any reliable solar charge controller for 36V lithium ion batteries???
I'm disconnecting the solar panels from the charge controller until the
voltage is below 40 again.
21st 2407.93, 1086.71, .00 => 0.43 [89048@16:30] Dull, wet. No storm.
22d 2409.69, 1087.47, .00 => 2.52 [89088@16:30] Some sun
today. Still no storm.
23rd 2411.02, 1088.08, .00 => 2.37 [55Km; 89131@17:30]
24th 2411.26, 1088.26, .00 => 0.42 [89178@17:00]
25th 2413.50, 1089.40, .00 => 3.38 [55Km; 89219@17:30]
26th 2415.42, 1090.46, .05 => 3.03 [89257@17:00] Running LED lights
(& the charge controller) for almost a week, the batteries have
finally dropped down in voltage to where the charge controller has put
in a bit of juice.
27th 2417.02, 1091.10, .06 => 2.30 [60Km; 89308@17:00]
28th 2418.16, 1091.96, .00 => 2.00 [89355@17:00]
29th 2418.60, 1092.19, .12 => 0.79 [89402@16:30] Ticking away, the
hours that make up a dull day.
30th 2419.40, 1092.61, .00 => 1.22 [55Km; 89444@16:30] New grid tie
at cabin but missed an hour in AM while installing.
01st 2420.53, 1093.20, .09 => 1.81 [55Km; 89489@16:30] Started
snowing in evening.
02 d 2421.50, 1093.20, .00 => 0.97 [89542@22:00] More snow. I
brushed snow off 2 panels on post & 3 on lawn. Sun for a while.
Cord to cabin had come unplugged... when and for how long? no power
there! Probably not much under snow covered panels anyway.
03rd 2422.13, 1093.21, .05 => 0.69 [85Km; 89608@24:30] The solar
panels at the cabin were still 1/2 covered with snow.
Daily KWH from solar panels. (Compare November 2021
with October 2021 & with November 2020.)
(14 solar panels)
(2 doing not much!)
(12 solar panels ->
14 by end of month)
(12 solar panels)
| 917 Km
Monthly Summaries: Solar Generated KWH [& Power used from
March 1-31: 116.19 + ------ + 105.93 = 222.12 KWH - solar [786 KWH
April - 1-30: 136.87 + ------ + 121.97 = 258.84 KWH [608 KWH]
May - 1-31: 156.23 + ------ + 147.47 = 303.70 KWH [543 KWH] (11th
solar panel connected on lawn on 26th)
June - 1-30: 146.63 + 15.65 + 115.26 = 277.54 KWH [374 KWH] (36V, 250W
Hot Water Heater installed on 7th)
July - 1-31: 134.06 + 19.06 + 120.86 = 273.98 KWH [342 KWH]
August 1-31:127.47 + 11.44+91.82+(8/10)*96.29 = 307.76 KWH [334 KWH]
(12th solar panel connected on lawn Aug. 1)
Sept.- 1-30: 110.72 + 15.30 + 84.91 = 210.93 KWH [408 KWH]
(solar includes 2/10 of 96.29)
Oct. - 1-31: 55.67 + 13.03 + 51.82 = 120.52 KWH, solar
[635 KWH used from grid]
Nov. - 1-30: 36.51 + 6.31 + 26.29 = 69.11
KWH, solar [653 KWH used from grid]
Dec. - 1-23: 18.98 + .84* + 11.70 =
KWH, solar + wind [711 KWH + 414 (while away) = 1125 from grid]
Jan. - 6-31: 17.52 + ------* + 10.61 = 28.13 KWH,
wind [1111 KWH from grid]
Feb. - 1-29: 56.83 + ------* + 35.17 = 92.00 KWH,
solar + wind [963 KWH from grid]
* The solar DC system was running the kitchen hot water
tank. Now it's only running a couple of
lights - not (usually) worth reporting. So there's just the 2 grid tie
house and "roof over travel trailer".
One year of solar!
March - 1-31: 111.31 + 87.05 = 198.37 KWH solar total
[934 KWH from grid]
April - 1-30: 156.09 + 115.12 = 271.21 [784 KWH
May - 1-31: 181.97 + 131.21 = 313.18 KWH
Solar [723 KWH from grid]
June - 1-30: 164.04 + 119.81 = 283.82 KWH Solar [455 KWH
July - 1-31: 190.13 + 110.05 = 300.18 KWH Solar [340
KWH from grid]
August- 1-31: 121.81 + 83.62 = 205.43 KWH Solar [385KWH
Sept. - 1-30: 110.68 + 65.09 = 175.77 KWH Solar [564
KWH used from grid]
Oct. - 1-31: 67.28 + 42.55 = 109.83
KWH Solar [1360 KWH from grid -- Renters!]
Nov. - 1-30: 35.70 + 20.79 = 56.49
KWH of Solar [1301 KWH from grid]
Dec. - 1-31: 19.78 + 11.31 = 31.09
KWH Solar [1078 KWH used from grid]
Jan. - 1-31: 25.47 + 18.58 = 44.05
KWH Solar [1185 KWH used from grid]
Feb. - 1-28: 47.18 + 33.22 = 80.40
KWH Solar [1121 KWH used from grid]
Two years of solar!
March - 1-31: 81.73 + 55.22 + 2.2 (DC) = 139.15 KWH
[1039 KWH grid]
April - 1-30: 161.83 + 112.35 + .44(DC) = 274.62 KWH
[680 KWH from grid]
May - 1-31: 156.25 + 97.22 + 1.29(DC) = 254.76
Solar [678 KWH from grid]
June - 1-30: 197.84 + 112.07 + 2.21(DC) = 312.12 KWH Solar
[& 448 KWH from grid]
July - 1-31: 204.35 + 121.21 + 4.06(DC) = 329.62 KWH
Solar [426 KWH from grid; 150(?) KWH used by Nissan Leaf]
August- 1-31: 176.19 + 102.91 + 5.37(DC) = 284.47 KWH Solar [477 KWH
from grid; 165 KWH (est) used by car]
Sept. - 1-30: 94.35 + 51.34 + 3.30(DC) =
152.29 KWH Solar [590 KWH from grid; 155 KWH (est) used by car]
Oct. - 1-31: 77.52 + 41.85 +
4.10(DC) = 123.47 KWH Solar [1066 KWH from grid; 150 KWH (est) used by
Nov. - 1-31: 34.69 + 18.92 + 3.82 = 57.43
KWH Solar [1474 KWH from grid (ouch!); 140 (est) used by car]
Things Noted - November 2021
* Toward the end of the month tree shadows even from across the highway
and from the acreage to the south were seriously interfering with solar
collection. It's another reason there isn't much solar in the winter.
* I don't drive every day but when I do it's generally a 55 or 85 Km
trip. Looking at the power usage, the car isn't a very big part of the
total load. In winter electric heat is most of it. The solar production
accounts for substantially more than the car uses, and the solar
equipment cost a lot less than the car did.
March 2019-Feb. 2020: 2196.15 KWH Solar [used 7927 KWH from
March 2020-Feb. 2021: 2069.82 KWH Solar [used 11294 KWH from grid]
(See TE News #156 for the two year writeup... which technicly should
have been two months earlier.)
Haida Gwaii, BC Canada