building microwind and microhydro generators

[Dominic-Luc Webb]

Looking for some tips on homemade microwind and
microhydro generators.

I have a site near the top of a mountain far from any
power utilities. It is intended for camping trips and
will end up with either a quite small cabin or
small motorhome. It is hard to predict what my power
needs will be, but much less than a typical home. I
am guessing 1-10 kW*hr generation is my goal with
intermittant use, like only on weekends.

The wind can be very strong, but variable. There is
a creek running through the property. I am told the
flow is 144 miner's inches per second, and that this
is roughly 1 cubic foot per second.

Here are some questions:

1. My understanding is that an induction generator
would be a good choice as long as I make sure I build
up sufficient RPM. Assuming I have access to junk and
scrap yards, what is a good source?

2. Assuming induction generator is good choice, are
planetary gear or belt drive arrangements used with
these to maintain high RPM?

3. Assuming total electric need is not great, I have
heard of using water pumps. Anyone know if the pump
from an old washer machine would work? Seems to me
that in their usual config, they pump a lot of water,
so I wonder if running water through this would generate
enough current to charge, for instance, a couple marine
batteries. I do not have sufficient specs handy to make
a sane guess.

4. As for the wind generator, are the powerful neodymium
magnetics found in hardware stores a good choice?

5. Schematics? Anyone know websites with reliable
instructions on how to build either of these from
scratch on a micro scale?

Dominic

 

[Dominic-Luc Webb]

I should maybe add to this that as regards the microhydro,
I would really like to find out about the the most eco
friendly method since this site is otherwise pristine.

Dominic

 

[Ecnerwal]

Looking for some tips on homemade microwind and
microhydro generators.

Lord knows where you are getting your info now, (induction generators
make no sense off grid) but try

http://www.otherpower.com

Lots of useful info, especially if you take the time to read through
"the old stuff" (what they used to do) and learn from what they have
changed after experience, rather than re-inventing the wheel yourself.

 

[Dominic-Luc Webb]

Lord knows where you are getting your info now, (induction generators
make no sense off grid) but try

Wikipedi, amongst others. My understanding is that it is
convenient way to get a stable AC frequency.

http://www.otherpower.com

Thanks!

Dominic

 

[Eeyore]

Looking for some tips on homemade microwind and
microhydro generators.

Try the energy groups, esp alt.energy.homepower

This one's well considered btw.
http://www.scoraigwind.com/

Graham

 

[Eeyore]

I should maybe add to this that as regards the microhydro,
I would really like to find out about the the most eco
friendly method since this site is otherwise pristine.

Define 'eco friendly' !

In one energy group there's a poster who has made his own microhydro
using a Pelton Wheel method. He posts often. Look in the archives.
As well as the homepower group look at alt.energy.reneweable.

Beware of the 'free power' overunity cranks around esp in sci.energy.

Graham

 

[Eeyore]

My first guess at a quick & dirty generator would be a car alternator,
at least if you just want 12VDC from lead-acid batteries. It's very
best feature is that if you pick one that's common then replacement
parts can be found at the nearest junkyard (or the nearest neighbor with
the right vehicle, if you're not terribly scrupulous).

They're pretty inefficient. Permament magnet alternators can do much better.

Graham

 

[Eeyore]

If you can't do the calculations, I wouldn't attempt the project.

100% agreed. Beware the shysters selling garbage too.

Graham

 

[Eeyore]

That's nothing new. Fuel cells have been a joke for 50 years at least.

Never mind the 'hydrogen economy'. Sadly most greens and politicians have no
brains, so they think it's the greatest 'new thing'.

Graham

 

[Dominic-Luc Webb]

I'm pretty sure that neither are feasible, certainly at the 1 KW power
level.

You can calculate the power possible from 1 cf/sec water flow, but you
have to know the head (pressure) available. I knew a guy who had a
stream on a hillside; he built a small dam uphill and ran a pipe from
there down to his house, diverting part of the stream's flow, and ran
a pump backwards, spinning an alternator. He had over 200 feet of
vertical drop, so got close to 100 psi pressure to work with. I don't
think it was worth the effort, and you'd probably have to divert your
entire stream to get useful output. Figure under 50% efficiency for a
good water-wheel and a good generator, much less if you use makeshift
stuff.

If you can't do the calculations, I wouldn't attempt the project.

John

Thanks for ideas. I am quite able to do some math, but need
to get some tips on reasoning this correctly. My friend now
tells me that he made a mistake and the flow is more like
100 liter/s. I do not think we can realistically get that
level of vertical drop you mention.

Dominic

 

[Dominic-Luc Webb]

Try the energy groups, esp alt.energy.homepower

This one's well considered btw.
http://www.scoraigwind.com/

Graham

Thanks!

Dominic

 

[Dominic-Luc Webb]

Define 'eco friendly' !
Graham

I am not yet sure what is and is not eco friendly, but
I am not going to dig up the entire area. Ideally,
when I leave this world, the generator can disappear
without a trace of having been there. This can be
done with a wind generator.

Dominic

 

[Dave Saum]

http://www.alternative-energy-news.info/micro-hydro-power-pros-and-cons/

 

[Dominic-Luc Webb]

They're pretty inefficient. Permament magnet alternators can do much better.

Graham

I am not following this actually. From what I can find, the
conventional, at least classical, automomotive and marine
alternators are 3 phase brushless generators with no
commutators and the schematics I have been able to find for
these show a slotted stator with coils and a rotor with
permanent magnets. This looks essentially same as the
homemade wind generators I have seen so far. I know that
some "alternators" are actually DC generators with solid
state diodes. I do not know how to tell one from the other
when I am in the junkyard, but that is maybe a separate
question.

Is is not so that a true automotive/marine alternator uses
permanenent magnets? I know the marine ones are built to
not produce sparking that could ignite fires in engine rooms.

I now think 3 phase is my starting point, so let us assume
I will stay on this track. For wind generation, I note
that nearly all the small scale and home made wind generators
are using 12-18 slot stators (and 3 phase). As compared to
the 2 slot alternator, this implies the goal is to be able
to get 50/60 Hz at comparatively low RPM. The automotive
ones achieve their relative high RPM by using a pulley ratio
with the comparatively slower engine at idle, engine
have the larger pulley.

Is there any reason why I should not just use a car
alternator (if they have permanent magnets) and similarly
also use a pulley to get more RPM if needed?

Also, does anyone know how many poles or slots on a car
alternator and roughly how many RPM when the engine is at
idle (ballpark)?

Dominic

 

[Dominic-Luc Webb]

Thanks Peter!

I just found this, as a further answer to my question. It
is taken from an advert for a high output alternator in
Ebay:

This alternator will drop right in place of your existing
(factory) 90-amp unit and operates with the existing ecm
voltage regulator.

65-70 amps capability at 800 engine rpm
165 amps at 1600 engine rpm.

If a common truck alternator can actually generate 90 amp
at ~12 volt at the stated RPMs above, then it if a
homemade wind turbine can physically get it to turn at
this RPM, as with a pulley ratio, this would compete
extremely well with the very best homemade wind generators
I have been able to find online in which the actual
alternator components were handmade.

So even if these alternators are not efficient, and even
if they are not of optimal design, as in lacking
permanent magnets, they are quite efficient compared
to the handmade alternators that do have permanent
magnets.

Having would coils by hand, I know this is a delicate
process and am not surprised if a factory made car
alternator is better than what I could make by hand
with what is theoretically superior design and
materials.

If there are no serious objections, I think I should
just go ahead and try the car alternator.

Dominic

 

[Jamie]

Thanks Peter!

I just found this, as a further answer to my question. It
is taken from an advert for a high output alternator in
Ebay:

This alternator will drop right in place of your existing
(factory) 90-amp unit and operates with the existing ecm
voltage regulator.

65-70 amps capability at 800 engine rpm
165 amps at 1600 engine rpm.

If a common truck alternator can actually generate 90 amp
at ~12 volt at the stated RPMs above, then it if a
homemade wind turbine can physically get it to turn at
this RPM, as with a pulley ratio, this would compete
extremely well with the very best homemade wind generators
I have been able to find online in which the actual
alternator components were handmade.

So even if these alternators are not efficient, and even
if they are not of optimal design, as in lacking
permanent magnets, they are quite efficient compared
to the handmade alternators that do have permanent
magnets.

Having would coils by hand, I know this is a delicate
process and am not surprised if a factory made car
alternator is better than what I could make by hand
with what is theoretically superior design and
materials.

If there are no serious objections, I think I should
just go ahead and try the car alternator.

Dominic

You most likely are talking about a brushless alternator.

Still functionally the same as the old style brush alternators
except for the method used to energize the rotor.

Instead of brushes, they use a DC coil that surrounds the
rotor into a slotted groove of the rotor or a side plate, in this
area, the rotor has a pick up coil that generates energy from the DC
magnetic field as its moving through it. This will excite the field and
not much current is needed for this.

This removes the need for brushes and also allows for a tighter
moister seal on the encasement of the coil..



http://webpages.charter.net/jamie_5"

 

[Jasen Betts]

I am not following this actually. From what I can find, the
conventional, at least classical, automomotive and marine
alternators are 3 phase brushless generators with no
commutators and the schematics I have been able to find for
these show a slotted stator with coils and a rotor with
permanent magnets.

often the rotor has an electromagnet which is powered by slip-rings
, and this power is switched to control the output of the altenator.

This looks essentially same as the
homemade wind generators I have seen so far. I know that
some "alternators" are actually DC generators with solid
state diodes. I do not know how to tell one from the other
when I am in the junkyard, but that is maybe a separate
question.

very few automotive altenators provide external AC terminals, most
have the rectifiers built-in, the aotomotice mechanics still call them
altenators though.

Is is not so that a true automotive/marine alternator uses
permanenent magnets? I know the marine ones are built to
not produce sparking that could ignite fires in engine rooms.

marine ones could be permanenent magnet, all the auto one's I've seen
had an electromagnet rotor.

On the other hand marine ones could have a stationary field
winding and a rotor that redistributes the field.

I now think 3 phase is my starting point, so let us assume
I will stay on this track. For wind generation, I note
that nearly all the small scale and home made wind generators
are using 12-18 slot stators (and 3 phase). As compared to
the 2 slot alternator, this implies the goal is to be able
to get 50/60 Hz at comparatively low RPM. The automotive
ones achieve their relative high RPM by using a pulley ratio
with the comparatively slower engine at idle, engine
have the larger pulley.

Is there any reason why I should not just use a car
alternator (if they have permanent magnets) and similarly
also use a pulley to get more RPM if needed?

vee pulleys have lots of friction. but it's possible a grooved of
toothed belt could work. chain or gears may be a better method,

Also, does anyone know how many poles or slots on a car
alternator

typically 5 or 6 of each north and south on the rotor, so
15 or 18 poles on the stator

and roughly how many RPM when the engine is at

idle (ballpark)?

idle RPM 500-1000 (larger engines are slower)