On Aug 16, 7:42 am, " email@example.com"
If you figure that most of the ACs are cycling randomly on
their own, then I don't see how the power company cycling
them is going to do anything to reduce the load, unless
they cycle them off enough that they can't run as much
as they would under thermostat only control. In that case
they do reduce the load and the temp in the building rises.
THAT is how I think it works. The rise is small enough
that most people don't notice it. But we had one report
here of someone that did have a problem with an upstairs
becoming too hot. And that seems possible and logical
On Thu, 16 Aug 2012 07:53:11 -0700 (PDT), " firstname.lastname@example.org"
That's sorta where I'm going with this. If the cycle time is shorter than the
normal off-time of the AC, there is no savings. If it's longer, the
temperature rises above the set point. On the hottest days, when one would
expect the cycling would become necessary, this time gets shorter. IOW, I
don't see this working, at least as advertised.
On 08/15/2012 07:23 PM, email@example.com wrote:
Now you don't have every compressor trying to turn on at the same time,
and can count on a certain percentage of them not even running. Ten
minutes later that compressor comes back on and operates normally, and
the next block gets shut down for ten minutes, and so on and so forth.
This assumes that your house is insulated enough to withstand the 10
minutes without the A/C going, and that your unit is properly sized.
One would have to assume they take these factors into consideration in
order for a person to qualify for the program, as it wouldn't make sense
to extend the offer to a tin shack with an undersized unit.
On 8/16/2012 9:06 AM, firstname.lastname@example.org wrote:
that's the point. hopefully if you keep moving that problem 10 minutes
into the future, at some point, some heavy load is going to switch off
(factory, etc), and they won't have to buy spot electricity, which is
even higher than normal in cost.
You can only move it ten minutes. You can't move it further because that AC
is now on. You've saved nothing. In 48 cycles (an 8-hour day), you've pushed
10 minutes worth of electricity for 1/48th of the ACs, after the (first shift)
load drops off. Whoopie!
On 8/16/2012 9:56 AM, email@example.com wrote:
if you need XMW of power right now, and you only have (X-5%)MW
available, you have to buy more. if you turn off 5%, you don't have to
buy that 5% on the spot market.
the next 10 minutes, you still have X-5% available, and if your load is
not X-5 then, you still don't have to buy more. you turn on that 5% load
that you had turned off, and turn off a different 5%. if your load has
gone up, you turn off more than 5% to keep your load under what you can
generate. you keep doing this until your load matches your generation,
and then you have enough in your own generating facilities to not buy
I don't know how your AC works, but all the ones
I've had cycle on and off randomly. Therefore the
cooling load is what it is. You can't reduce it by
shifting the load out 10 mins. You have to DECREASE
that load for real, by not letting the AC run as much
as it would if it had power available constantly. And
that translates into the temp in the building going
Let's say it's a very hot day. From 1PM to 5PM the
power company sees it needs to reduce demand
because either the system could go down or they
would have to buy more very expensive power.
All the ACs out there are either running constantly
or cycling on and off. If they are running constantly,
then obviously turning them off for 10 mins every so
often is going to reduce the load, but it will also reduce
If they are cycling on and off, then with all of them
together, it's already randomized. Nothing the
power company can do is going to reduce the load
without it also causing less cooling going into
Just look at it from an energy balance point.
If the power company can reduce it's power
output from 1PM to 5PM by 5% by screwing
with shifting in 10 min periods, how could all
the buildings be as cool as they would be
with no intervention? How did we supply
the same BTUs to all those customers
buildings with 5% less power? Why not just
do this miracle 24/7 and save everyone a
lot of money?
Sure, you can do that. But you can't do it without
less cooling at the buildings with those AC's being
turned off by the power company.
On Aug 15, 10:23 pm, " firstname.lastname@example.org"
That's what I'd like to know too. The only way this
reduces the load the utility sees is if they actually reduce
the cooling going into the home or business, by
repeatedly cycling them so that they run less than if
they were not being cycled. But they
typically claim that it has no effect, which I believe is
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