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Re: [Phys-l] The West Wing



Richard!

The problem is like apples and oranges. Your data is for the country, mine the temperate. Of course my argument is tempered by that fact, but it's still true, in the Sun Belt water heating may not be the majority, but certainly the plurality. Here's data for our ~ 2ksf home. Aprox. 100 year old, but w/ the ceiling of the ~ 20 year old second floor addition insulated (its foot print is ~ 1/2 the first's, and the windows are double glazed.
'05/05 => '06/04 12 month average 1.34 therms/day; the six months average when the furnaces were used is 1.77 t/d
previous year 12 month average is 1.63 the seven months furnace used is 2.13 t/d

The May thru Oct. '05 average is 1.0 t/d, so obviously that year heating water was over 50% of the use [note only GK uses the oven, about once a month and the other use is occasional heating of water for pasta, pot stickers, etc., and the pressure cooker (rice and potatoes) -- it was several months after moving in that we bought a stove, and I think what prompted that so soon was the ugly mt space!] However, that year is unusual as Pacific Gas and E. offered a 20% rebate over the winter three months if we cut our use 10%. So I delayed crawling under the house to ignite the pilots about two months and became a boy scout. Several neighbors donated their lumber from remodels and I burned our deck; It's now artificial lumber. I estimate we saved about $200. Furthermore, we replaced all the windows the Summer between the two years, as some had obviously failed (water in-between). So for '04/'05: June thru Oct. the average is 0.94 for the other months it's 2.1. So ~ 1.16 average therms for "space heat" seven months and about one, all year for water, or about 61% of our gas use is for water. I suspect a well designed solar heater would supply this for about seven months. More in Riverside, my example of temperate climate, where the rainfall is only ten inches while Salinas's is fifteen, and several hundred miles further north.

Now regarding our use of units. [I think this is similar to the Moses Denker contretemps.] I don't think it makes sense to use photovoltaics to heat water! So I assumed kWh referred to direct e use only. I suggest using Joules, as it doesn't imply e. energy.

There's more, as I must look at the DOE data. The link was posted after I whereto most of the above.

bc, who would appreciate reading his other false info.

p.s. reading below, about 1/3 each transportation, domestic, and industry energy consumption. I don't think there's much argument that rail and ship are considerably more efficient than truck / auto. Their nearly exclusive use along w/ very economically encouraged mass transit and car pooling would, I think reduce transp. to 20%. I suspect if the efficiencies Calif. has achieved were applied to the US, would result in domestic reduction to 20% also. I suspect industry is already at max. efficiency. Reduction in our ridiculously high consumption is necessary.






Richard Tarara wrote:

There is so much false information here that I will refrain from attacking
it all--but see a few comments below.



[Original Message]
From: Bernard Cleyet <bernardcleyet@redshift.com>
To: Forum for Physics Educators <phys-l@carnot.physics.buffalo.edu>
Date: 5/26/2006 12:05:16 PM
Subject: Re: [Phys-l] The West Wing

Rick!

You've adopted the assumptions of the energy enterprises. By doing so you reach their desired conclusion.

It still may be necessary to depend on concentrated energy sources (C and U based power stations), but to a much lesser extent if it's done w/ more thought. In temperate climates the greatest energy demand is water heating. At the turn of the century this was accomplish in, for example, Riverside when all the homes had roof top solar water heaters before the importation of natural gas. Whether done directly or w/ a heat exchanger, they are inherently more efficient than using gas or electricity. I agree very high densities (many people housed under a small foot print) require pour stations. However, I suspect such density will become economically inviable and those cities will disappear.


The biggest domestic use of energy is space heating--not water
heating--about 20% of the total demand.

I think BCs biggest problem is one that the press also gets confused
on--electrical energy satisfies only about 20% of our total energy demand. I may use kWh as an energy unit, but that doesn't mean that I am talking
about only electrical energy!



Furthermore, I suspect we are very far from the possible savings thru increased efficiency. I've reported before we halved! our e bill by switching to CFLs. Including all the costs, environmental, etc., if governments were to give away CFLs they'd be ahead *. I think incandescents should be taxed at $1/W.


* Back a few decades, environmentalist suggested giving away Rabbit diesels would pay for themselves.

bc

p.s. our e use (domestic) is 4 kWh/ year. So our indirect use (manufacturing food, etc.) is 76k -- wow. so industry is the culprit.


NO! Again, confusing electrical with total energy use. The 80,000
kWh/year is all energy use. Individually, about 27% of that is
transportation, a similar percentage for domestic and commercial use, and
again about as much for industry, with some usage for agriculture.

Our personal energy use averages out quite a bit higher than 4
kWh/year--that may be about right for home electrical use which only shows
what a small percentage things like lighting really are. Consider that
this 4 out of 80 includes all home lighting, and appliances, (and often hot
water). The space heating, the rest of the hot water, and all our gasoline
use adds considerably more to the individual use total.

Again--while low density power (wind and solar and biomass) will play major
roles in our energy futures, without continued high density energy (coal or
nuclear) the land use becomes prohibitive. To put my earlier figure of
1300 square miles of photovoltaic material to power (all energy needs) of
Chicago into perspective--that is is between 2 and 3 times the area covered
by the entire Interstate Highway system in this country! To cover the load
with wind generators would require about 400,000 1-MegaWatt units. ;-(

Rick


Rick Tarara wrote:


As always, check out the 'reality' here with numbers. Let's take the Chicago area--roughly 10 million people. At the national average usage

of
80,000 kWh/year (total energy use) that is close to a trillion (10^12)

kWh
annually. If Chicago had a desert climate (maybe it will in a couple decades due to global warming ;-) then the annual solar absorption would

be
about 2000 kWh/y/m^2. At a 15% conversion rate, it would require over

3000
km^2 (1300 mi^2) of photovoltaics to provide the energy. Then of course

you
also need a way to store the energy to provide some at night.

At some point the 'small is beautiful' group came to realize (or will

need
to realize) that high population density areas need high density power

and
nuclear IS an available technology that is safer and cleaner than coal. While natural gas is probably safer, it is not cleaner (greenhouse and

other
air pollution) and our proven reserves of gas are tenuous. Ultimately,

cost
may not be the overriding factor. Environmental impact and land use may become more important.

[Aside: I have often seen the argument that high density power is not needed for countries like India BECAUSE that country is still 70% rural. However...this misses the fact that the urban population is over 300

million
people--more than the entire population of the U.S. Bottom line: distributed energy sources are too land intensive to be a viable

solution
unless mixed with _some_ forms of high density energy production. In

the
near term (50-100 years) that will need to be nuclear if we get serious about reducing the use of fossil fuels for environmental concerns.]

Rick

*********************************************************
Richard W. Tarara
Professor of Physics
Saint Mary's College
Notre Dame, Indiana
rtarara@saintmarys.edu
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----- Original Message ----- From: "Hugh Haskell" <hhaskell@mindspring.com>
To: "Forum for Physics Educators" <phys-l@carnot.physics.buffalo.edu>
Sent: Thursday, May 25, 2006 11:58 PM
Subject: Re: [Phys-l] The West Wing





At 09:34 -0400 5/25/06, jbellina wrote:


Many years ago a friend got interested in what drove people to be, at
the time, strongly pro-solar and anti-nuclear. It turned out to have
little to do with technology as such and more to do with power and
the size of the technology. Solar was small, local and comfy, and
nuclear was large dark and powerful. So how do you address that issue?



That doesn't seem like too bad a characterization to me. It isn't
just that solar is warm and fuzzy, it that it is local. Distributed
power production has some advantages in efficiency--very little
transmission line loss, and the possibility of using the waste heat

from the power generation to provide space heating. Nuclear is big,

needs to be (but isn't always) remote, requiring long transmission
lines, and, compared to solar, much less safe, and then there is the
problem of the radioactive waste products that never seem to go away.

Uranium mining isn't the most pleasant occupation, either, since it
has all the usual difficulties involved in mining plus radioactivity.
I presume, however, that the manufacture of solar panels isn't
entirely benign, so on balance, that may be pretty much a wash.

Processing uranium to be used in a reactor, however, gets more and
more expensive, in both dollars and energy as the quality of the ore
declines with time. At some point, I suspect that the energy budget
for processing the fuel will be such that all of the output of the
plant will be used to process the fuel to run the plant. I think
nuclear will become less than practical long before we reach that
point, however.

The characterization was made during the "small is beautiful" era,
which, alas, seems to have passed. I still think it has great merit
as a slogan, for the idea of distributed power generation.

Hugh
--

Hugh Haskell
<mailto:haskell@ncssm.edu>
<mailto:hhaskell@mindspring.com>

(919) 467-7610

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