On Mon, 4 Feb 2013 19:44:51 -0500, "Ralph Mowery"
wrote:


wrote in message
...

Follow the example. It doesn't require 100% efficiency. You have a
river
that's flowing at 100MW an hour. During the day, there is a market
for
all that power. At night the demand is only 60MW. So, you could let
that water pass by unused or use the 40MW available to pump water
to a reservoir above the power plant. Then, during the day when you
need more than 100MW, you release some of that water. You now
have more than 100MW of water availble to turn the generator
because you have EXTRA water beyond what the river supplies
during that peak period.
Hence you can produce more than 100MW of power during the
day when you need it.


Because there is no dam behind the falls? Think Niagara. How do you
stop up the flow? During the day they can only deflect so much water
into the generators - must maintain minimum flow over the falls. -
Now they COULD build a "lake" a few feet higher than the inlet of the
generator and only have to lift the water a small amount form ABOVE
the falls overnight to fill the reservoir - which is then available to
supplement flow during peak power periods the next day.

There are many situations where the same could be done, with a
definite net gain in power output.

That makes no sense at all. You are saying let the water flow past the dam.
Then pump it back up to the top ? It is not like getting the water down
stream 10 miles or more from the dam. Why not just cut the flow back to the
demand for power.