On Apr 13, 2:50*am, Bruce Richmond wrote:
On Apr 11, 2:19*am, David Nebenzahl wrote:





On 4/10/2011 10:02 PM Bruce Richmond spake thus:

On Apr 10, 3:54 am, David Nebenzahl wrote:

That second statement is correct: you can't "push" electrons into
the grid. But it doesn't matter *how* your inverters are working;
it's a basic law of physics.

If you apply more volts to a line than what it is carrying what do you
think happens? *I run machines that use regenerative braking. *They
draw energy from the line to set things in motion. *To slow or stop
them the electric motor acts as a generator producing a higher voltage
than the grid, forcing power back into the grid. *An inverter can do
the same thing using solid state circuits. *The inverter in my Prius
takes DC current from the battery and converts it to whatever voltage
and frequency is needed at the time to run the variable frequency AC
motor. *When slowing down the motor becomes an AC generator and the
inverter converts the output to a DC voltage just a bit higher than
the battery, pumping charge back into it.

Sorry, I don't think you know what you're talking about.

If you do a little research I think you will change your mind.

http://en.wikipedia.org/wiki/Grid_tie_inverter

At the bottom of that page you will find this link

http://www.solarpanelsplus.com/solar...r-Inverters-Wo...

You seem to think that you can "force" or push "voltage" into a line, by
using a higher voltage than what's on the line.

More specificly I wrote, "forcing power back into the grid". *Power is
watts or KW. *That's volts times amps. *The current will only flow if
there is a difference in voltage.

That's not at all what's at work here when one has a photovoltaic system
and an intertie feeding power back into "the grid".

The intertie and the house's power connection are going to be at pretty
much exactly the same voltage. What happens is that the PV system is
connected *in parallel* with the grid; it's dumping more *current* into
the system, not more voltage.

It takes very little voltage difference to flow a lot of current when
the "load" is the grid.

You do understand the difference between current and voltage, don't you?

Yes, I do. *Now let's see if you can understand this.

Take two 12 volt car batteries with one discharged to 11 volts.
Connect them in parallel and check the voltage. *It will be some value
between what they measured seperately. *While they are connected like
this current is flowing from the charged battery to the discharged
battery. *Power is being forced into it raising its state of charge.
If the two batteries had been at exactly the same voltage there would
have been no current flow. *Now take 8 AAA batteries connected in
series to give 12 volts. *Disconnect the charged battery and connect
the AAAs to the 11 volt battery. *Measure the voltage. *It will be for
all practical purposes unchanged from 11 volts. *The AAA cells are
charging the bigger battery but they are so small compared to it that
they seem insignificant. *That is how your PV system looks to the
grid.

The voltage on the grid can vary by up to + or - 10%. *It is usually
kept withing + or - 5%. *Take a volt meter and check the voltage at
your wall outlet. *Check it several times during the day and you will
find that it varies. *Don't try to claim that it doesn't, check it and
you will find that it does. *As loads are put on the grid it drags the
voltage down. *The power company responds by generating more power to
bring the voltage back up. *As loads are taken off the voltage will
climb, and it is brought back down by producing less power.

The point here is that there is no such thing as the grid not being
able to accept the power you have produced. *As long as you are
connected you can always force your KW in.- Hide quoted text -

- Show quoted text -

Assuming someone is taking it out somewhere you can :-)