Sylvia Else wrote:
mm wrote:
On Thu, 29 Oct 2009 10:59:12 +1100, Sylvia Else

Most homeowners don't really need air conditioning anyhow. They
should open the windows and buy some fans. My greatgrandparents
didn't even have electric fans.

I have AC installed. It only gets used for a dozen days a year (and a
few nights) at most. But at those times, it wouldn't be much fun without
it. The problem with comparing the present situation with that in the
past is that people in the past didn't have a choice, just as they
didn't have a choice about dying from diseases that are now either
easily treatable, or easily preventable.

Even fans are not so effective when the air is so warm that sitting in
front of a fan feels like sitting in front of a fan heater.

Exactly. Every year there are deaths attributed to "lack of
adequate cooling". But, its usually "not anyone *you* know"
so it tends to get ignored. Just like folks freezing to death.

Would I survive if I didn't have AC? Probably. Would I like it? No.

The problem with "excess heat" is there aren't many ways of
"shedding it". And, once your body starts to overheat,
*you* usually aren't qualified to think about how to fix the
problem (it muddies your thinking).

In a way, I shouldn't take this money for putting a switch on my AC.
I only use it for 2 or 3 weeks most summers anyhow, so they probably
don't cut down the load when they radio me. Last summer was the
least hot of my life, and I didn't use the AC at all.

It's fair to take the money. The infrastructure required to support
extreme peak loads (which is not just generators, but transmission gear
as well - lines, switches, transformers, the works) is only used
infrequently. If the need for it can be obviated by persuading people
not to use it, then there is a substantial cost saving. Although you may
only use AC for two or three weeks in the summer, it's likely to be the
same two or three weeks that other people are using it.

Exactly.

D, it was pretty easy to get me to sign on. They pay 10 or 15 dollars
(I forget which) dollars a month during the summer for the AC and
since I almost never use the AC, it's defitely a bargain. But I think
a substantial percentage of people have signed up, 10, 20, 30 percent
or more. I have one friend who uses it all summer who did.
They also pay maybe 5 dollars a month during the summer for the water
heater. I don't know why, but I didn't like the idea of them
fiddling with that.

That actually makes more sense. It encourages people to have tanks with
a decent capacity so that turning them off at times of high load has no
impact. My own hot water is heated overnight at a lower tarif anyway.

A smarter solution is to have "on demand" water heaters. Silly to
keep 40 - 80 gallons of hot water available 24/7 just in case
you *might* need it. This solution is a throwback to days when
heating water was a slow process and you didn't want to
"inconvenience" the user. :-/

I think I thought it woudl come out ugly looking,
even though it is in the basement, sort of like the AC did the second
time (I had signed up 10 years ago during the previous round. I don't
know if BG&E had the first round that Dave mentioned.)

I get the impression they only turn off the power for short periods
two or three days a summer. Maybe 20 days at the most in a hot
summer.

I can't even see how that would help them. ACs run on thermostats. Turn
them off for a while, and they'll simply run for longer when they're
turned back on. So unless they're left off until the peak load drops
(ie, because the outside temperature has, or at least the sun goes
down), there'll be little or no net saving.

Hotels use the same approach with their in-room HVAC units:
they aren't all "enabled" at the same time. In years past,
a simple time sharing scheme was used: some portion of the
units were enabled for N minutes; then, another portion for
the next N minutes; etc. The point being that the units could
bring the room to "the desired temerature" (on average) when
used for only a fraction of the time (i.e., they didn't need
to run at 100% duty cycle to work properly).

Nowadays, technologies like ZigBee are being deployed to
allow for smarter management. E.g., instead of blindly
enabling some portion "now" and another group "later", just
let each unit that *wants* power *request* power. And,
force it to wait until that request is granted (by some
centralized smarts that is tracking who it has "granted"
power to at the present time). So, if you get lucky,
only X% of units will *want* power at any given time.
If more than X% do, then you have to decide how to
limit the actual number of units to that percentage
(i.e., you are back to the original solution) knowing that
*eventually* each room will achieve its desired temperature.

The real problem power suppliers face is that consumers are not subject
to the true costs of supplying the power. Indeed, those consumers who
cannot afford things that create high peaks, like airconditioning, are
subsidising those who can. In Sydney, where I live, time of day metering
is being introduced, which at least charges more during period where
demand tends to be higher, but even they don't ramp up the cost during
heat waves. As an AC owner, I'm not complaining, but it doesn't seem at
all equitable.

Some (US) businesses are charged based on peak demand.
Stated simplisticly, if you use electricity at an X KWHr rate
for 10 minutes and don't use *any* thereafter, you are
charged a rate proportional to X *regardless* of your
TOTAL energy consumption during that billing period (month)!

Things like ToU and Peak tariffs lead to some incredibly
inefficient solutions that waste energy -- but, "save money".
E.g., businesses "make ice" overnight to run their air
conditioning systems during the following day. The cost
of making the ice is artificially cheaper than creating
the same "cooling" during the day (when it is actually
*needed*)

shrug