|
|
re: check out my electric bill, how is this possible?
28 jan 2001
nightbat wrote:
>...i worked for a utility company for years...
perhaps this affected your brain. did you learn to use numbers when
talking about energy savings?
>they now will pay you to allow them to place a load limiter on your
>water heater in times of electric shortage.
a "load limiter," eh?
for years, utilities sought to maximize their investment in order to
maximize their returns under pucs that allowed them to make x% of every
dollar they could invest. this was an unstable system. if the pucs turned
their backs on the utilities for a minute, the utilities would start
installing gold-plated wires in the name of reliability :-) utilities still
do strange politically-motivated things like peco's paying 22 cents/kwh
for pv (but not cogen) power delivered at peak times in exchange for being
allowed to charge customers for $6.3 billion in stranded costs for stupid
investments.
off-peak water heater timers _controlled by a utility_ can save money
for customers and peak capacity for utilities, but it looks to me that
they don't save any energy if the timer uses more than 0.3 watts...
>remember, the new water heaters are very energy efficient due to using
>more insulation...
so they stay warmer overnight, and the setback savings are even less.
>if you time them around your schedule, then you can only be charged for
>when you need and actually use the hot water.
no. the water stays quite warm overnight and continues to lose heat
through the tank walls whether you turn off the power or not.
>...my bill was cut in half by the use of the clock.
using off-peak rates, no doubt. altho there's another effect: install
something like this (even a placebo) while talking about energy savings
and a typical person will become more energy-frugal... years ago a nj
agency went through a housing project doing weatherization on every other
building, and the residents of the unweatherized buildings ended up using
about 20% less energy.
>does it really work, ask any utility company. (:~)
right... :-)
>> >...place a clock timer on your water heater...
>> a 50 gallon water heater with 30 ft^2 of r10 insulation has a 133 hour
>> time constant. if you set it for 120 f, and turn it off for 7 hours
>> in a 70 f room, it cools to 70+(120-70)exp(-7/133) = 117.4 f, with
>> an average temp of about 118.7 at night. this saves 7h(120-118.7)3btu/h-f
>> = 26.8 btu/day or 9800 btu/year, ie 2.9 kwh, worth 29 cents per year
>> at 10 cents/kwh, but the timer itself likely consumes more than that.
did you learn to use numbers when talking about energy savings?
nick
|
|
