# Feeding solar power back into municipal grid: Issues and finger-pointing - Page 16

Posted by trader4@optonline.net on April 14, 2011, 3:52 pm

For once I agree with Harry.   We can forget about generators and
distributions systems.  Just take two 12V batteries and connect
them in parallel to a 12ohm resistor.  Under Homeguy's
theories, I don;t know what he thinks would happen.  But
clearly he thinks if we put a second AC power source on
a distributions system, it has to be at a higher voltage to
"push" current out.

So, what happens with the two batteries?   Under the laws
of physics the rest of us use the voltage would remain at
12 volts and BOTH batteries would be supplying part of
the 1 AMP flowing through the resistors.

Posted by krw@att.bizzzzzzzzzzzz on April 14, 2011, 11:40 pm

On Thu, 14 Apr 2011 08:52:52 -0700 (PDT), "trader4@optonline.net"

Oh, but according to Homeguy, that doesn't work because batteries are VOLTAGE
sources.  <slap!>

Not on Homeguy's and Vaughn's planet.  One of the batteries will be charging
the other.

Posted by Home Guy on April 15, 2011, 4:27 am
"krw@att.bizzzzzzzzzzzz" wrote:

It's usually not a good idea to connect batteries together in parallel,
unless they are exactly of the same type, age, condition, etc.  If you
get a weak cell in one of the batteries it will turn into a load.

And what happens when they are not exactly at the same voltage before
being connected together?  How do you insure that you always get current
flowing out of both of them?

The IEEE paper I posted earlier today shows exactly that - that PV
systems raise local grid voltage and the utility company must compensate
by reducing primary supply voltage to down-regulate the secondary
voltage coming from the distribution transformer.

Take a 12 V car battery and wire it up in parallel with 8 AAA batteries
connected in series.  Then connect a load and tell me how much current
the AAA batteries will supply vs their what their potential current
supply could be if they were connected to their own isolated load.

If they are unequal in capacity, then yes that will eventually happen.

Posted by krw@att.bizzzzzzzzzzzz on April 15, 2011, 4:46 am

What a dumbass!

They will share in proportion to their capacity.  Electricity, water, nor shit
flow uphill.  ...though you have been pumping enough of the latter here.

Posted by Jim Wilkins on April 15, 2011, 11:54 am

How to properly analyze the problem:
http://www.electronics-tutorials.ws/dccircuits/dcp_4.html

Look at Example 1.

jsw

•
• Subject
• Author
• Date
 Re: Feeding solar power back into municipal grid: ... krw@att.bizzzzz... 04-18-2011
 Re: Feeding solar power back into municipal grid: ... David Nebenzahl 04-18-2011
 Re: Feeding solar power back into municipal grid: ... David Nebenzahl 04-18-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-18-2011
 Re: Feeding solar power back into municipal grid: ... David Nebenzahl 04-18-2011
 Re: Feeding solar power back into municipal grid: ... krw@att.bizzzzz... 04-19-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-19-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-19-2011
 Re: Feeding solar power back into municipal grid: ... David Nebenzahl 04-19-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-19-2011
 Re: Feeding solar power back into municipal grid: ... David Nebenzahl 04-18-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-19-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-18-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-15-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-15-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-15-2011
 Re: Feeding solar power back into municipal grid: ... Daniel who want... 04-14-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-14-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-17-2011