[mdlug] Router - now power.

[Aaron Kulkis]

Robert Adkins wrote:
>> You could do what they do in the electrical engineering 
>> building at Purdue... the incoming AC drives a 3-phase 
>> electric motor, which drives an AC generator....with a very 
>> large flywheel in the mix.
>>
>> These keeps the high voltage lab (10,000 V) from getting 
>> spikes which would easily go over 1 MV due to the transformer 
>> step-ups.
>>
>> With good bearings, this is quiet enough that I never 
>> suspected such a thing until I actually saw it in the basement.
>>
>> The only thing needed are some big knife-switches on the 
>> house (load) [side that are kept in place by presence of 
>> current], so that if the power goes out, you can spin up the 
>> flywheel before the generator (and hence the
>> motor) sees the load from the refrigerator and other heavy motors.
>>
>> Might not be cheap initially, but the output is perfectly 
>> sinusoidal, and the equipment lifetime is measured in decades 
>> or longer -- especially if you use brushless motors and 
>> generators (i.e. magnets are in the rotors, not the housing [stator]).
>>
> 
> 	Sounds like quite a project. Interesting, but I don't know if that
> is something that I would really need for a home that is slightly over 1400
> square feet.
> 
>>> actually blows through my neighborhood, I'm considering installing 
>>> some of those micro wind turbines that are made out in the 
>> Grand Rapids area.
>> Good luck on recouping your cost on that.
>>
>> The European experience with wind generation of electricity 
>> is that material and maintenance costs exceeded the 
>> electricity produced.
>>
> 
> 	If that's really the case, then why is anyone bothering to produce
> any wind power generating equipment.
> 

Because the EPA and DoE are PAYING people to make these uneconomical contraptions.

Without subsidies, their true costs are exposed, and they're just not
profitable.  The Europeans wasted billions on these schemes.

> 	There's plenty of different methods for generating wind power and
> one of the prevailing setups has been utilizing a shedload of precision
> gears and drive shafts to transfer the wind down to the ground level
> generator. Which, as I understand it, causes a significant loss of potential
> energy generation.

All fine and good until you try to store it for later use.
All of these methods have horrible loss rates ( > 50%)


> 
> 	Some newer thoughts on ths matter is to eliminate all the gears and
> shafts and have the turbine blades directly spin the generator. As I recall,
> the energy difference is very significant, the only issue with that design
> is that any maintenance would need to be done at the top of the tower. That
> sort of maintenance could likely be alleviated with better construction and
> perhaps some automated low power monitoring and simple self-lubricating
> systems.


The problem is the same as in ships:  Turbines work best at high speed,
(thousands of RPM) but propellers work best in the 100-400 RPM range
due to cavitation and vibration effects, which makes direct drive
turbine systems inefficient (either the turbines are spinning too
slowly for maximum work extraction from the steam, or the props are
spinning too fast and cavitating -- not only losing lots of power
to creating vacuums, but also beating up the propellers pretty badly
as well)

Similarly, we need gears to adjust speeds, although a tri-phase
generator producing 60 Hz can be run at 3600 RPM, the most
efficient designs, as I recall, produce 3 cycles for every
revolution, dropping the operating speed down to 1200 RPM
to produce 60 Hz power.

> 
> 	There's other designs that look like pieces of art and are able to
> generate power via even the lightest of breezes. They are virtical "fans"
> that spin around a shaft and are able to generate electricity regardless of
> the direction that they spin.

Great if your only concern is some small load such as pumping water,
but not so good if you're trying to force the power that you're
producing onto the grid.

> 
> 	Nifty stuff is out there and while some/much of it is still rather
> expensive, economy of scale is more than willing to bring those costs down.
> 

The Europeans have been trying to make those economies of scale
to work for 20 years, and they're poorer for it.  And it's not
like any of this is new technology.

Windmills go back to the middle ages. AC generators are over 150
years old, and modern airfoils and turbines are 100-year old
technology.

Windpower will never do anything more than nip at the edges of the
total electric load.  Even if we had a 500 MW windpower farm, we
would still have to build another 500 MW conventional or nuclear
boiler+steam turbing power plant to cover when there is no wind.
And since these steam-powered plants literally take days to go
from offline to online, there's basically NO SAVINGS to building
giant wind farms (other than killing birds and ruining the view).