|
|
re: wind energy for my home
9 aug 1996
matthew scott wrote:
>stargazr@mindspring.com (robert miller) writes of:
>>...10 or more standard automotive alternators on the ridge of the roof of
>>my house. on each have a windmill. the power from each will be modest but
>>connected in series could create enough energy to be worth while wouldn't it?
i think this is an interesting idea, and a lot cheaper than 10 air-303s.
my junkyard sells used alternators for about $10 each, and they will make
almost a kw at high rpm, i think, but the voltage and power aren't much
at low rpm. i wonder what blade diameter would be best?
the tip of a 2 bladed prop might spin 10 times faster than the wind, so larger
blades turn slower, and the alternator is the bottleneck, and tiny blades
collect little wind, so that limits the power output for tiny blades, so it
seems there's an optimal size in the middle...
could we string the alternators between the roof peak and a beam above the
roof, like this, with simple wooden 4' downwind blades, with one 1/4" dacron
rope holding each alternator up and another rope holding it down?
-------------------------- ..........
sailcloth . .
enhancer? . . . .
-------------------------- .
| | . | b .
| | | l
alt alt ... 6'? . alt-a . 2x6s on 4' centers?
| | | d
| | . | e .
-------------------------- .
ridge . . . .
. house .
. .
>just remember that in series connection, resistance values rise high.
my gut feeling is that this would not be a problem. putting the alternators
in series raises the voltage, which is good (each alternator might have all
3 phases rectified, in series, too) and simplifies the wiring. and moving
power at a higher voltage means less i^2r wiring loss.
>getting slow generators to be efficient requires large magnets.
i suppose these alternators would have field coils, not magnets. would it
be more efficient to use a low field voltage and current in light winds,
and a higher voltage and current in higher winds?
how about pulsing the field current some small percentage of the time,
to get a higher voltage for a second, and slow down the blade, then let
the blade spin up and do it again?
could we do this 60 times a second, with alternating polarities, and
feed the power back to the grid? :-)
nick
|
|
