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For my most recent gas bill, the cost per 1000 cuft hit $15.27 not
including transportation charges, taxes, and monthly service fees.
That
comes out to $15.27E-6 per BTU for heating my house (plus the other
fees
that are not included; and, if I were achieving 100% efficiency in my
furnace).
Let's convert this to kilowatt hours so we can compare it to
electricity
costs....
Natural gas comes out to $0.052 per kilowatt-hour for heating for gas
cost alone. Taxes, delivery, and service in my area bring this up to
about $0.062/kWhr, and this still assumes I don't waste any thermal
energy out my flue.
Electricity in my area is 90% generated by coal and 10% by nuclear, and
is fairly inexpensive at $0.062 on my last bill including tax,
transmission, and monthly service charges.
This means that for the first time I can remember, the cost of heating
with natural gas has hit the cost of heating with electric resistance
heat, if you assume a 100% efficient furnace. Some furnaces hit 95%
efficiency, but most are more like 80%. This means that today I can
heat my house with electric resistance heaters for less out-of-pocket
cost than heating with natural gas. Of course electricity costs are
also expected to rise, but not as much as further increases in natural
gas. In my area we don't use gas turbines for electricity except for
just a few small peaking plants, and those only tend to run in the
summer.
I did this calculation today because there has just been a big push at
the local school, and the push is about come at my university, for us
to
turn our computers and monitors off at night in order to save money. I
have always told people that turning off lights and computers and other
things at night during the heating season does not save as much money
as
they think. It only saves the cost differential between gas heat and
electric heat.
Well, as of today, there is no cost savings to be gained by turning
electric things off at night. If you heat with natural gas in my area,
you can now actually save money by leaving your computers on all night.
The truth of the matter is that it's not much money either way. To
receive Energy Star status a computer in sleep mode must use less than
15 watts and a monitor must use less than 2 watts. But most computers
are better than this. The most recent round of computers purchased by
the university use 1.6 watts in the computer and 0.7 watts in the
monitor for a total of 2.3 watts when in sleep mode. That's about half
of a 4-watt night light or one-third of a 7-watt night light.
*One-hundred* of these computers left on from 6 pm to 8 am for *one
month* would cost $5.80 if you don't consider the benefit of the heat
generated, and would save the university about $1.27 if you do consider
that natural-gas heat now costs more than electricity.
I presented these numbers to the administration today, and they were
flabbergasted. They thought they were going to save several-hundred
dollars per month in electricity costs by making us go around our
offices and labs each night and turning off all computers and monitors.
Where do they come up with these ideas? We are small, and only have
about 400 university-owned computers on our campus. All are Energy
Star
compliant. The maximum savings would be less than $25 per month not
considering the benefit of 2.3 watts of electrical heat per computer.
Currently we save four or five dollars a month by leaving all computers
on during the night.