Tri-Polar
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Post by Tri-Polar on Oct 4, 2021 14:22:14 GMT 10
So, been thinking about it again lately. I was thinking of adding some wind turbines to the shed roof to generate power at night. Why only at night? Because the solar controller would overload with sun and wind at the same time.
Has anyone something along these lines?
Ive tried searching for such tings as, time delay, remote switches, time switch and a few other variants to try and research this thought.
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frostbite
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Post by frostbite on Oct 4, 2021 14:28:19 GMT 10
Is your night time wind reliable?
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Tri-Polar
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Post by Tri-Polar on Oct 4, 2021 14:42:48 GMT 10
Im not looking to run power form it, but would like to supplement grid power. Itll be a stepping stone for when i either get a larger inverter or 2.
But as it sits now, plenty of wind around which is why i sparked up a thought again.
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malewithatail
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Post by malewithatail on Oct 4, 2021 15:53:17 GMT 10
Grid connect wind is possible, but due to the intermittent nature of it, its not popular with the power authorities.
I have installed grid interactive wind generator, integrated with solar and a battery bank. Trace made a series of inverters that could run stand alone and grid interactive, where they fed excess power back to the grid and took power from the grid when needed. Obviously, the grid metering was a bit different as two meters were required, a demand meter and a feed in meter. Now metering is available that has smarts in it that can sort out which direction the power is flowing and log it appropriately.
The system would also drop off the grid when it failed, and run stand alone for as long as the solar and/or batterys held up. In one case after a bad storm that felled power lines, the system ran for over 5 days without issue, and the neighbors were visiting the chap wanting their mobile phone and computers charged ! A great way to get to know the neighbors.
There are issues with sources, such as wind and hydro, and that is what to do with the power when the batterys are charged, or the grid fails. For safety, a shunt regulator is usually used to dump all the power as turbine will speed up and could self destruct on no load. Simply turning out of the wind isnt enough and the consequences of failure can be very very bad.
That said, on the east coast here, the combination of wind and solar works very well together, especially in places such as Robertson on the highlands above Wollongong and along the coastal fringe where sea breezes are consistent after dark.
The last point I want to make here is that of wind quality. Just having wind isnt enough, it has to be not to strong and not too blustery or changing direction to often as this puts extra mechanical stress on the turbine and its mounts.
There are many different types of wind generators, and yes, its possible to make your own, although grid connecting it may involve certification issues with homemade gear thats not approved. Darranious rotors are easy to make and many designs exist, see Mother Earth News for some.
Having been in the industry for many years, since its beginning in the 1980's and writing the original installation guidelines, I think with the cost of solar panels, 2nd hand, being almost freely given away, solar with a large lead acid battery bank is the way to go, to give 20 + years of off grid service. not withstanding, we have over 2 weeks of battery storage with no solar input, plus a silenced diesel 12 kva backup, a Honda 8.5 kva that run duel fuel (gas and petrol), and a 3.5 kva Honda that runs from wood gas via a pyroliser unit. And that doesn't take into account that the reliability of the grid is falling, and it will go down. It is a blessing to be able to run a couple of dehydrators, irrigation pumps, solar hot water boosted by the solar electric system and several freezers, fridges, all the light we want, whenever we want, all for nothing, nix, free. The added security such a system gives can not be overstated. Its nice to stick the finger up at the electric companies, and lead on these companies always sending you e-mails giving their latest and greatest solar deals. When I ask them if they are going to buy back our 50 kwh + per day, they never reply !
Seeing a severe storm approaching, then reading or hearing about 50,000 people without power, saddens me as its so easy with today's technology to be relatively free from that stress point.
Your independence from the grid should be as vital as food production, storage water supply and so on is. To have some semblance of normality after a collapse, electric power will become a neceesity for society to recover.
Start off small, run your radio gear and the shed, progress to a fridge then as you learn, expand the system. Yes, it will be expensive and its a learning curve, but on line tutorials are available to explain watts, volts, amps etc.
I have put together several tutorials over the years and if enough interest is shown, can find one or two and post them.
Our society is collapsing, Government is corrupted, the system will fail, are you ready to start rebuilding ? Electric power, or the knowledge to create it from the duterious of a failed society, will make you a vital person in the new world. Ive always said that knowledge will be the new currency after the collapse, and electric power and the know-how to make it, will be a sought after skill, even a tradable one, especially for those who have stocked up on the gear needed, or know how to make a regulator, or charger etc from junk left lying around.
Civilization isnt going back to oil lamps and open cooking fires, well, it might for a while, but if you are prepared for collapse, you will be back up and running sooner.
There will be enough stress in just living, growing enough food for survival without worrying about having light so you can mend things after dark, ready for the next day. Enough ramblings.
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Post by Joey on Oct 4, 2021 16:49:08 GMT 10
Failing to find anything automated, you could also just do bare basics to get you started and have a switch on the input wires to the charge controller from the turbines and just have to make the effort to remember to switch them on and off each day.
Another way you could do it simply is maybe run the wires from the turbines into a standard 240v wall socket (not connected to mains of course) and put a plug-in timer on that before it goes into the invertor. This would depend on finding a programmable timer that doesn't need to run on 240v to power its timer
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Tri-Polar
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Post by Tri-Polar on Oct 4, 2021 18:08:52 GMT 10
I had thought of this, but i had the impression (perhaps from research) that generating power from them with no where to go is bad for them?
Im all for manually switching it Its not that im lazy, just worried it might end up damaging something during the process.
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malewithatail
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Post by malewithatail on Oct 4, 2021 20:02:19 GMT 10
Thats right, tri polar, you cant run turbines on no or light loads as the speed increases dramatically and they can destroy themselves, and possibly you too. Shunt regulators, or some form of mechanism to turn the wind turbine out of the wind, or shut off the water flow to a hydro is required. (Don't forget water hammer, always turn off a turbine slowly as the pipe can be split apart from water hammer)It is possible to build a turbine that can withstand such forces without damage (A 3 phase induction motor connected as an induction alternator can do it), but the tower etc still has to withstand the forces involved, especially if its spinning at 10,000 rpm and the wind changes direction. Then catching that spinning load, that's running at perhaps 10 X its normal speed, and has stored up a lot of energy in the process, is difficult and the sudden shock of slowing down can damage windings by ripping them out of the slots, or impose forces on the blades and other gear that they were not normally designed to withstand.
Somewhere here ive got the spare pelton 4P turbine wheel that I got for our water turbine on our last farm. It generated over 1 Kw at 240 volts directly, using a 2.2 kw 3 phase motor as an induction alternator, and some capacitors to excite the magnetic field, at a head of 100 meters (800 kpA), and a flow of about 3 liters/second. (I think, it was nearly 20 years ago).
Just do it.....
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bug
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Post by bug on Nov 24, 2021 7:50:51 GMT 10
Really wouldn't bother with a small wind generator. They just aren't worth it. Too many moving parts to fail. The small 'off grid' ones generally require much higher wind speeds to work than the big wind farm ones do.
Given how cheap solar is now, you're far better off getting a larger PV array and angling some of the panels in sunrise and sunset directions rather than due north. The total kWh generation will be slightly less, but crucially, the period you rely on your battery will reduce. Even on crappy solar days, if you've got a decent battery you'll be fine if you do this.
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Tim Horton
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Post by Tim Horton on Jun 22, 2022 10:46:43 GMT 10
A small bit of trivia I can add...
Way back when I was a kid, my grandpa had an old 1930s-40s (?) wind generator on the roof of an old shop building.. Note this was a propeller driven generator, not alternator... It may have been only 6V capable (?) He used it to top off an old car, or tractor battery occasionally..
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I know a lot of "homemade" engine powered alternator set ups use a General Motors style, 1 wire alternator as they have a voltage regulator, and maybe other controls built in.. I have very little electrical knowledge, but think a wind system like this is reasonably simple to set up with a battery and all to run some lights and other simple applications.. I suspect where complications come about are with higher consuming appliances, and multiple systems in use ??
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malewithatail
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Post by malewithatail on Jun 22, 2022 11:30:55 GMT 10
A few comments all.
1) An conventional alternator needs a field current, usually supplied via the ignition light, to exite and produce power.
2) This creates a 'knee' or kink in the power input needed to kick it off, hence, it takes up to 1 hp for a fraction of a second to get it going.
3) The turbine has to supply this power. Its no issue when connected to a car engine as its power is almost infinite to the alternator.
4) Permanent magnet alternators are usually used for small wind and hydro generators, overcoming the need for excitation of the magnetic field as its permanently there, hence the term permanent magnet.
5) A reasonably efficient alternator can be made from a 3 phase, low voltage motor, like from a pancake or muffin type cooling fan. They have permanent magnets and a wound stator. U swill need a 3 phase rectifier bridge, but that's not hard to make from Jaycar bits n pieces. Also called a dc induction motor.
6) Using a second shunt or bypass regulator and a couple of 'steering' diodes gets around the issue of overloading the solar regulator, which is probably a MPPT or PWM type and totally unsuited to regulating a wind generator. (Note Some Plasmatronics regulators can do shunt and series regulation at the same time).
7) A shunt regulator is needed as when a turbine is unloaded, as when the battery's are full, it can speed up and destroy itself.
8) If 'steering' type diodes are not used, the regulators can fight each other and the battery's wont/might not, fully charge.
9) It aint as simple as it seems, a bit like life I suppose.
10) There are other types of ways of making an efficient wind or hydro generator, using the C2C configuration of a 3 phase motor and the correct delta (220 v, 3 phase), connection. But this is not low voltage any more, but generates at 240 volts. Be careful, you are now in licensed electricians territory.
11) Old style DC generators didn't have the issue of excitation, as most had a residual magnetic field that when the generator was spun, kicked itself off easily. But, brush wear was an issue. My first hydro generator was made from a Pelton 5P runner, and a 12 volt, 22 amp generator from a landrover. Brushes lasted a week or so, then the commutator was worn out a month later. Didn't work. My neighbor used a car alternator and replaced the brushes every few weeks and rebuilt the slip rings every few months or so. Not very good either. My hydro generator was a permanent magnet motor/generator set with the 3 phase, 220 volt motor removed and the 400 volt, 200 cycles alternator rewound to output about 36 volts. Frequency didn't matter as it was converted to DC anyway. A homemade shunt regulator completed the setup. That worked for many years, until I installed the 3 phase induction motor, configured as above, and generated directly at 240 volts ac. Apart from replacing the bearings every few years, the system was still running 20 years later when we sold that farm.
12) Wind-power Australia produced a range of wind generators based on their own specially made alternator and regulators. They were very efficient, and ranged in power levels from 500 watts, up to many Kilowatts.
13) I made a small wind generator from a permanent magnet alternator (from a Honda Zot car) and the blades made from heavy duty sewer pipe Worked well enough, but the constant flexing of the blades broke them off after a while)
14) An aeroplane propeller wont work, its designed to 'pull' air around, not be driven by the air. The twist, etc is all wrong.
15) Look at Diraneous rotors, no slip rings or tail needed, as its a vertical axis turbine.
16) Have a go mate, you will soon learn what works and what doesn't, but be careful, keep away from it in strong winds in case you've made a blue and it throws itself apart.
If you believe in telekinesis, raise my hand.
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