[Phys-L] Re: Natural Gas vs Electricity

[anngeorg at PACBELL.NET (Bernard Cleyet)]

comments for the replies I remember.

The most saving is always to shut of the heat source completely when not
needed.  The artist cum Physics teacher devotes considerable time to
this in his book(s).  So heat at night is cheaper only if ice will
damage the pipes, and if you can't wear sweaters, then spend the $$.
[My friend the Staffordshire county councilor's wife would hand us
sweaters when we visited in the winter.  This stopped when he finally
got the $$ (maybe he accepted a bribe -- just kidding.) to install
central heating in the late sixties.]  Hewitt also has pic. of tower
blocks w/ their lights on at night,  for heating.

As the extraction and environmental cost goes up, electricity will
become less expensive than gas, oil, and coal, if it's generated by
nuclear, wind water, etc.  My rule of thumb during the fifties was $gas
= (1/2) electricity.  I see it's changed radically!

A recent article somewhere warned about the cost of those plug in the
wall P/S's.  I have one that consumes 10W! with the output unplugged.  A
quick count about 9 in our house. Most consume about 3 watts idling.
Then all those VCR's, six, and others that consume while idle e.g. three
TV's.  Some HP test equip consume while in standby.  Our printers HP
deskjet 5650 consume (each) < 3 W on or not.  While printing ~ 5 W xcpt
when moving the paper, then jumps momentarily to ~ 15 W.  They are
energy starred.


bc

Michael Edmiston wrote:
> 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.
>
> Michael D. Edmiston, Ph.D.
> Professor of Physics and Chemistry
> Bluffton University
> Bluffton, OH 45817
> (419)-358-3270
> edmiston@bluffton.edu