Savonius rotor (generator)

LockH

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Ummm.. Started out in Victoria BC Canada, then sta
So, still only "Search found 15 matches: +Savonius" on ES, and one "negative" point "Savonius rotors are really not efficient". (Accounting hat/blinkers/red flashing lights/sirens on), but, but, but, ain't "efficiency" = costs "in" vs costs "out"?

And the cost of winds is???


Ed: But the "formula" for "efficiency" might include MAXIMUM costs out versus MINIMUM costs in.
 
Try HERE

The guy is Ed Lenz, and is very helpful. I have one of his designs ready to put up, IF, the damn crate I'm waiting on, for 2 months, ever shows up, :roll:

It's a 3 wing design using lift to help it through the drag part of turning. Efficiency has been tested at around 30%, if I remember correctly. I plan on a couple more for when the sun doesn't shine, or, the rainy season is past. No NEED for high towers, either, within reason.
 
Good stuff, Big H!

(Unfortunately, (the Welsh Canadian in me, I suppose) looking for "simpler" (cheaper) eg scrap cloth from a sail maker, etc.)

Hehe.
 
When it comes to electricity, RPMs really count. The 3-bladed axial that is common is the most often seen for a reason. I am a fan of the vertical axis wind turbine (VAWT), but they have decent torque with unimpressive RPMs. If you build a large enough one, you can add a 2:1 gear-up to increase the generator RPMs, due to the good torque.

The biggest problem with wind gens is that the best wind is usually 30 feet or more above the roof of your house. If you attach it to your house, it will send a resonate vibration through the house when winds are high. Most jurisdictions don't allow them as an eyesore. Most homeowners insurance won't cover your house if you install one. If you have property out in a rural area, you have to put the wind gen far enough away from all buildings so there is a safe "fall zone" during a storm.

If you get past all these concerns, it's a fun project. The Lenz-2 is an efficient design, and it is also pretty affordable to build. If you attach a 1:2 reduction, (to slow the output and add torque) you can have it turn a small air compressor to a check valve into an old propane tank. Free non-electric air pressure to run an air-tool for a few minutes.

When air pressure builds up in front of a wind gen (of any type) any additional wind "goes around" it.
 
Ed shows a video of a 1 wing on a turntable with a fan blowing across it. That 1 wing will fully revolve. I'm building mine with a 36" center to center of the 3 wings, and 6' tall, by using 2 sets of 3 wings.

I'm as rural as one can be, so, I have full open access to the prevailing wind direction, and soon, will be cutting a couple rows of our tree thinnings, to allow the wind to proceed past the turbine(s), before stacking up, as you stated.

I will be doing an axial PM alternator on each turbine I build, so, slow speed torque will be good, and also gearing it to run at LEAST 2:1 or 3:1, alternator to turbine.

I still don't have a large enough battery to need a great amount of generation. I am experimenting and adding to the system, so, one day, I can open the knife switch to the meter of the power company, and can always close it if needed.

Trying to get the computer and all lights off the power company, then, TV @ 12v and then, refrigerator, if only at a reduced usage of power company, as I get more batteries and power generation going.

Need to come up with an alternate clothes washer and dryer. Washers here, start, spin, stop. Reverse start, spin, and stop. etc., etc. Mostly using surge voltage on every cycle, which draws more than steady running. Need to move a couple of big rocks up near the house, and a system to spray water over them, as a Rube Goldberg device thrashes the clothes against the rocks. :roll:
 
"RPMs really count."
Sooo... a really large diameter gear spinning a tiny gear/axle?

"biggest problem with wind gens is that the best wind is usually 30 feet or more above the roof of your house."

Currently trying to interest a neighbour of mine (Club manager) in the idea:
https://www.torontohunt.com/

... so a long waterfront property, only less than 100 feet from the lake (and about 300 feet above same).

Sooo, multiple smaller rotors standing upright planted in the ground or held up by ropes/wires to surrounding trees maybe.

Good thought about the small air compressors!

And re "air pressures going around it", so Dutch windmills anybuddy?
 
LockH said:
"RPMs really count."
Sooo... a really large diameter gear spinning a tiny gear/axle?
You just added a gearbox. Wind is free, but components to harvest it are not.

Use a savonius for low speed torque applications, like a slow grinder or trommel. Don't make electricity with one. You'll get about 15% of the Betz limit out of the wind - so about 7% at best.

LockH said:
Sooo, multiple smaller rotors standing upright planted in the ground or held up by ropes/wires to surrounding trees maybe.
You'll need to get the cost of one unit comparable to a tenth of the cost of one ten times the size. Build a Miller Rotor, not Ed Lenz's design.

LockH said:
Good thought about the small air compressors!
Air is a really poor working fluid. If you want to store energy mechanically, use potential energy and pump water or lift a weight.

And re "air pressures going around it", so Dutch windmills anybuddy?
Still happens. You can't escape the Betz limit.

Anarchistic answers to engineering questions which suggest that "science doesn't know everything" doesn't make sense with wind turbines. You just end up making yourself look silly.
We have all the formulas and we know all the optimisations. We just need to get the build costs down. It's not being negative because science doesn't care about our opinions.

I started a new wind turbine recently, 3d printed the VAWT blades to get the cost down, and mounting on another Maglev bearing to reduce friction. Wish I'd known about Miller rotors, I wouldn't have started trying to put lipstick on the pig that is the VAWT blade.

10326652_679024872176428_1475710060_n.jpg
10518094_936010763092036_1411124251_n.jpg
 
Good stuff Samd! Sooo... the cost of wind is? (Remind me again, please?) So perhaps the question might be watt MAX output (for a given/fixed costs of manufacture and maintenance). Yes?
 
Perhaps, if Mr LockH doesn't mind, we could discuss this "Miller Rotor" some more ? I did a Google, and, very little info is available. Someone on the "Backshed" forum, mentions corrugated roof tin ?? for the wings ?? It needs bracing, so, lets compare home made construction between the Miller and the Lenz ?? I'm a perfect example of having very limited material selection down here, BUT, I DO have several sheets of 28 gauge corrugated roof tin, 3.7 meters long X 815mm wide.

There is NO NEED for condescending conversation. I, for one, am very interested in finding the maximum output of the least expensive design out there. I also have a 1.37M dia 3 blade wood carved horizontal rotor that I had flying a short time, for balance, which, I believe, is going to be the hardest thing to accomplish with the 2 winged Miller rotor.

I used to sell wind turbines and install them, including building up to 120' tall telescoping towers, and, built from scratch, a 4KW, 15' span, 3 blade turbine, with feathering blades for overspeed prevention, so, lets get this discussion revved up, EH ??
 
"Perhaps, if Mr LockH doesn't mind"... Not at all Big H! (My middle name starts with an "H" BTW. And ends with a "D". Six letters long, though is sometimes shortened, to only five letters, ending with a "Y". For some reason.)

But yah. "Nutshell" explanation here, this thread all re sucking "FREE ENERGY" from our environment (in this case, solar via pressure gradients.)
http://en.wikipedia.org/wiki/Pressure_gradient

(Watt some may waste away, riding around by bettery-electric (sp?) traction and not spilling their "drinks".)













So lessee... Four parts?
1) Harvesting.
2) Storage.
3) Consumption.
4) Taxation.













(May have been joking `bout that fourth thingee.)

Okay, storage and consumption are... "open" for some other threads (see eg "water", also "height" etc. - And on and on. And so forth.) Leaves this thread primarily re *harvesting*. Si tout le monde s'il vous plaît?

(Hence the title of this thread.)


















(Emphasis here on low costs to install and maintain "machine".





... or machines. ;))
 
Previously Mr.L stated "used scrap sailmakers cloth". For EXAMPLE, the Lenz type can be fashioned from scrap exterior grade plywood. The strips can be from the same type plywood and epoxied/screwed to the plywood ends. The covering can be sailcloth, Muslin, whatever scraps can be found and PAINTED with exterior paint, after covering the wings, to stiffen the fabric and help with decomposition from the sun.

2 sealed bearings required to fit whatever shaft (pipe) used for the axle. I'm going to use pipe with solid shaft fastened in each end for the 1" pillow block OR flanged bearings. Pipe is laying here at my place. Bearings I can salvage from another project, for now. I have VERY strong weather resistant wood here, so, 20' (6 meter) 2" X 2½" pieces dug into the ground as sine posts and more as cross braces for each turbine, as needed. That will give me roughly 8-10 feet from the ground to the bottom of the double wing turbine. This is not ideal, but, will catch suitable available winds for my needs. As stated earlier, add another 2-3-4 turbines as needed.

Need some form of structural bracing. More 2 X 2½ pieces from the top posts to pieces set into the ground will be sufficient. Top wind speeds here are MAYBE 50-60 MPH gusts. I will install hydraulic motorcycle brake rotor and caliper on each shaft, to manually shut down in high gusty wind conditions.

My problem is, not enough batteries at this time to take whatever charge I can gather.

The examples I saw with the Miller Rotor, fastened to the F&P motor shaft, is not very strong and the out of balance will fracture the shaft, resulting in seperated flying rotor. No other examples found to offset this concern.
 
"enough batteries at this time to take whatever charge I can gather. "
Sooo... Nowhere to pump water "UP"???
 
Water is 450 feet away from the house, and, 100' below the house level, AND, it's all at the bottom of the hill where wind never blows because of trees, elevation, etc.

I've been studying this for 7 years to try to get max results from hydro/wind/solar.
 
So, no chance for windmills etc on the part of the property where the wind DOES blow? (EG flown hanging off wired "zeppelin". Just how high IS this property?)
 
Harold in CR said:
There is NO NEED for condescending conversation. I, for one, am very interested in finding the maximum output of the least expensive design out there.
Degree qualified engineers take hack advice by the unqualified in just the same way as qualified medical doctors take people recommending home remedies to those with a terminal illness. We naturally find it offensive. You need to see yourself as the root cause of the condescending response, not the recipient.
Installing turbines doesn't help you much with designing and fabricating them from scratch. I can install a television - wouldn't want to be in charge of building one.

So step through the design videos at Caleb's site and once you have decided what sort of power you need to make you can then focus on a cost effective design to harvest it. Going on a rambling romp through different designs and topics will be less productive.
http://www.calebengineering.com/basic-small-vawt-design.html
There used to be a VAWT site just like endless sphere, called VAWTs.net. Not sure what happened to it.
 
A nice little rotor for making about five watts. His single phase generator is really suited to a faster windspeed.
A multi phase generator would step it up a bit - a stepper motor ripped from an old printer or a low kV outrunner motor.
If you want a similar one, I have an old instructables to show how to do it.
http://www.instructables.com/id/Build-your-own-Savonius-VAWT-Vertical-Axis-Wind-T/

It still suffers from the low yield of the savonius design however.
If you just want to make heat you can drop the cost a bit by getting rid of the rectifiers and charge controllers and batteries and doing away with storage - just run the three or two phase wires in your window and dump the AC power directly into a bar heater or oil heater.

Have you studied the kinetic energy in the wind video yet? How big do you want to make your first rotor? If you let me know I can show you the effect of wind speed and why a faster bladed turbine is a good idea.
 
Well, say for example your land ends at the lake (and maybe is 300 feet up:
Bluffs.jpg








... and could shove a looooong pole to stick well out over the lake and from the cliff. (Think of it maybe as a tall flagpole, but lying on side.)




So, loooong spinning cable hanging from pole, supporting rotor, generator, wires back to shore, (Christmas decorations)










Anyway... I'm ball-parking maybe 5 percent output. Sometimes. For many DECADES.








(Also been trying to interest my neighbours in building a FUNicular device to go up/down those cliffs. Hehe)
 
Then just put a HAWT on it for 40 percent for many decades.
 
Cool. (Hope it's OK for an old raver/ebiker to say that here.)
 
Got an old DD ebike hub?

Pop some of these on it and orient it towards the direction most of your wind comes from.
http://www.reuk.co.uk/PVC-Wind-Turbine-Blades.htm

More blades means more torque and better startup.
Less blades means better top speed and peak power.
Find the best combo for your local wind profile.

Who would have thought you could combine ebikes and turbines as a hobby.
http://www.reuk.co.uk/PVC-Wind-Turbine-Blades.htm

A DD hub is pretty similar to a rewound Fisher and Paykel alternator.
 
"This drag-type VAWT turns relatively slowly, but yields a high torque. It is useful for grinding grain, pumping water, and many other tasks, but its slow rotational speeds make it unsuitable for generating electricity on a large-scale."

Hehe... "large-scale" (when I just want to recharge ebikes, hedge trimmers, etc. Above re Savonius from:)
http://www.teachergeek.org/wind_turbine_types.pdf
 
If you want to charge with a savonius at ~80 watts,
assuming you have wind at 10mph, or 15kph, equals ~4mps.

Power in wind for a square meter = 0.5*1.4*4*4*4*0.07(percent) = 3.1 watts per square meter.

So you'll need 80/1.8 = 44 square meters of savonius swept area.
Six meters high by six meters wide.
Nice Sav mate.

Grab a 20W solar panel or build a HAWT
 
Samd said:
Got an old DD ebike hub?

Pop some of these on it and orient it towards the direction most of your wind comes from.
http://www.reuk.co.uk/PVC-Wind-Turbine-Blades.htm

More blades means more torque and better startup.
Less blades means better top speed and peak power.
Find the best combo for your local wind profile.

Who would have thought you could combine ebikes and turbines as a hobby.
http://www.reuk.co.uk/PVC-Wind-Turbine-Blades.htm

A DD hub is pretty similar to a rewound Fisher and Paykel alternator.

Don't forget to fit some conical bearing to the hubbie. The bearings in bicycle hubmotors don't like the side loads.

Harold is on top of a hill, but plenty of trees there too. With 500W of solar cells in a box and a sheet of EVA to seal them, it's seems obvious which direction to go.

Lock has that lake and height, so start digging that pond. What about winter though?...kinda hard to make much electricity with ice. Plus ice has such a tendency to stuff.

I've got no room to talk. I have panels, blades for a 10ft turbine, motors, and even batteries and LED lighting, yet all I do is charge my ebike. :oops: I've got adjustable switchers in route, so soon I'll be able to do solar balance charging to eliminate my one concern about a big home based lithium pack.
 
`Been considering lead sheeting (available locally for old roofing repair) + sulpheric acid, (think big glass "fish tanks"):
http://endless-sphere.com/forums/viewtopic.php?f=14&t=57046

NOT for rolling transportation, but to store via PBA, to charge bettery packs (sp? sorry, meant "battery" there. My mistake.), etc.
 
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