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RE: Gas or Electric

The casualties from the Hindenburg disaster were the result of the burning
of the cloth that made up the superstructure covering and the diesel fuel
used to power the props, not the hydrogen gas.

There was a very good discussion of this topic on NPR's Talk of the Nation
shortly after the WTC attack.

Jamie Russell
Graduate Research Assistant
V: 803 777 0731
F: 803 777 0106

-----Original Message-----
From: Minicucci, Bob [mailto:rminicucci@des.state.nh.us]
Sent: Friday, January 11, 2002 8:20 AM
To: 'ryoder@mail.unomaha.edu'; p2tech@great-lakes.net
Subject: RE: Gas or Electric

At which point we must consider the manure management issue for the 1500
miniature horses required a 2000 home subdivision placed on 500 acres of
land.  The solution to this & the related sub-problems of stallion
management are left for the student...

No one in this discussion has mentioned the issue of why one maintains
'lawn' space.  For me, I maintain around 1 acre close-mowed (in addition to
about an acre meadow & the gardens), which is used for me & the kids running
around playing ball, shooting the fris, sledding, etc.  Many of these
alternative ground cover suggestions cover the visual aspects of 'lawn', but
it's hard to hit grounders on a rock garden ;)

Additionally, I think the image of the burning Hindenburg is an issue that
needs to be considered if we want to build general public acceptance of
hydrogen as a fuel.

Bob Minicucci
Illegitimati non carborundum

-----Original Message-----
From: ryoder@mail.unomaha.edu [mailto:ryoder@mail.unomaha.edu]
Sent: Thursday, January 10, 2002 4:09 PM
To: Brady, Bernard; p2tech@great-lakes.net
Cc: 'hhaines@state.mt.us'; 'Estes, Laura'
Subject: RE: Gas or Electric

just a note on H2 production -

one of the arguments against wind or solar power is that power capacity
isn't available when needed (still  or cloudy days) or is available when it
isn't needed.  i've oft considered hydrogen as an "energy battery" in this
case, allowing the overproduction to be stored in a portable (but not yet
universally usable.  Ahem,  at least until the fruition of the just
announced Bush administration focus on fuel cell cars instead of more
efficient fossil fuel vehicles) format.  Not my idea - it's something a
great shadetree mechanic, retired farmer type did just 15 miles from Iowa
State University, where I got my engineering degree.  Quite a guy - his old
windmill would generate electricity that he's use to power everything, but
when his production exceeded demand, he'd split the water into hydrogen and
oxygen.  Ran his tractor on the H2, used teh gas for a cutting torch and i
can't remember what else. No rumor this - saw the local news segment on it
and it was a discussion in class the following day - back in '81 or '82.
pretty neat...  but not commercially viable, evidently - which i always
thought was the stress cracking issue of H2 reaction with steel compounds -
but with fiberwound composite tanks, that shouldn't be an issue... must be
something else.

BTW - good point on the balance of what we like and what we don't.  If we
were thinking outside of the box, maybe we'd choose to genetically engineer
a horse or other grazing animal to fit in residential neighborhoods.  Oh,
wait!  It's been done - says here:
http://www.amha.com/ that with supplemental (for a balanced diet, I believe)
feed, the pasture size requirement for a Miniature Horse is 3 horses/acre,
or that "one can easily be kept in the average residential backyard,
depending upon local zoning laws"  Careful, those local zoning folks can be
real philistines.



Richard Yoder, PE
Director, P2ric.org
1313 Farnam St.   Ste. 230
Omaha, NE  68182

fax: 402-595-2385


                    "Brady, Bernard"

                    <bbra461@ECY.WA.GO        To:     "'Estes, Laura'"
<laurae@montana.edu>, "'P2Tech@great-lakes.net'" 
                    V>                        <P2Tech@great-lakes.net>

                    Sent by:                  cc:
"'hhaines@state.mt.us'" <hhaines@state.mt.us>                     
                    owner-p2tech@great        Subject:     RE: Gas or



                    01/10/02 12:20 PM

                    Please respond to

                    "Brady, Bernard"



It's always interesting to see that in these discussions, we attempt to
support the alternative we like by leaving out or overlooking some of its
negatives while loading up the alternative we don't like with all the
imaginable negatives. I agree with Howard Haines' points about the real
justifications for preferring electric mowers (cord or cordless) over
gasoline-powered being geographically specific. Outside LA, maybe, this is
tempest in a teapot. However, there are a couple of Howard's comments that
need correction. One is that gas turbine power plants are not more energy
efficient than thermal plants ... BTW: I assume he means coal-fired plants.
Gas turbine, coal-fired, and nuke all get electricity by converting from
heat. If typical coal-fired efficiency is 33 to 35% (Howard's Montana
example), they're a lot less efficient than a gas-fired turbine at 52 to
... I assume we're both talking about the ratio of the power output to fuel
heat value. And as for emissions, Howard suggested looking at the back end
of jet engines (for those who don't know it, gas turbines are jet engines
bolted down). That ain't fair. Gas turbines in power plants are now
to have selective catalytic and carbon monoxide catalyst control systems
that reduce NOx and CO (and some VOC) emissions to small fractions of what
comes out the back end of an uncontrolled jet engine.

The second comment is that fuel cells are 80% efficient. That's only true
for the conversion of hydrogen heat value to power output. Unfortunately,
there ain't no uncombined hydrogen around. Natural gas and coal are used in
a form not greatly different from the way they come out of the ground.
Gasoline is distilled from petroleum along with some reforming reactions to
break too big molecules down to gasoline range. Some energy value is lost
that process. But, you can only get hydrogen with a net energy value by
reforming it from a fossil fuel. So, you really start with something like
gasoline before you get to the fuel cell. Yes, you can get hydrogen
electrolytically from water, but you get no net heating value. You have to
use just as much energy (actually more) to separate hydrogen from oxygen as
you'd bet back by re-combining it at the fuel cell. Anyway, when you reform
the fossil fuel, say methane (the simplest), you lose the heat value of the
carbon part of the molecule. If I remember correctly, the net efficiency of
a reformer - fuel cell combo is about 50%. On the other hand, at the
emissions source, the emissions are only water and carbon dioxide.

Not that I expect anyone will really have read this far, but I finally have
a compulsion to offer my "what to do" suggestion: Keep using your
gas-powered mower 'til it wears out. Then replace it with whatever is most
cost effective and useful for you. Take care of it. Service it: Change the
oil, clean the filter, clean and/or replace the spark plug, drain and
dispose of the gas in the tank at the end of the mowing season. Set the
mower for the highest grass length. Cut the grass frequently enough to keep
your neighbors happy, but don't try for Better Homes and Gardens awards.
Water enough in the summer to keep the whole lawn from turning brown, but
not so much that your yard looks like a field of emerald green. Kill the
lawn weeds: By hand if you have time, or spot spray. Replace your lawn with
a vegetable or flower garden if you like. But, that'll be a lot more work
than the lawn, so be realistic. Don't worry. Be happy.

-----Original Message-----
From: Estes, Laura [mailto:laurae@montana.edu]
Sent: Thursday, January 10, 2002 9:30 AM
To: 'P2Tech@great-lakes.net'
Cc: 'hhaines@state.mt.us'
Subject: FW: Gas or Electric

This information from a colleague who has done quite a bit of engine
emissions work.

-----Original Message-----
From: Haines, Howard [mailto:hhaines@state.mt.us]
Sent: Wednesday, January 09, 2002 4:28 PM
To: 'Estes, Laura'; Tomas Vinson (E-mail)
Subject: RE: Gas or Electric

Dear Laura and Tomas,

I am not on the P2Tech, but you can post it there. This reads like someone
should have shown up at one of my workshops with the Health and Air Quality
Impacts of Bio-based Fuels and Lubes in Small Engines slide show. These
given in Montana, Minnesota (2), Michigan (7), New York, Washington D. C.,
and are now being done in parts of Canada.

As of January 2002, the newer lawnmowers would be the most efficient
mechanical units in terms of energy, CO2 emissions, and reduced pollution
for areas that do not have air quality problems.

Newer lawnmowers are almost all 4-stroke engines (see the EPA report at
OTAQ), and some have electronic fuel injection-quite a bit cleaner than
older 2-strokes, and more energy efficient (less CO2 emissions).  For data,
look at a number of reports by CARB and Southwest Research Institute.

In most of the data I have seen, the reasoning behind electric lawn mowers
(and vehicles) is to move the pollution out of an air shed that has poor
(exceeding regulated pollutant levels), and away from people, to an air
where the electricity is produced.  The idea is to reduce pollution at the
site of use so that other pollution sources (like industries that have
energy options) can operate in the same air shed.  In most cases when you
think about it, electric mowers don't make much sense except for the
companies.  True, a coal-steam plant in Montana may be 33 to 35 percent
efficient, but it looses (rule of thumb) about ten percent to move it down
to California.  With that size of operation, the typical battery and
recharge losses (30 to 45 percent) would cut the efficiency or increases
emissions even more.  From an energy or emissions standpoint, an electric
lawn mower is like cutting butter with a chainsaw.

Gas turbines for electric production are not all that efficient compared to
the large thermal plants, but they are cheap.  As for emissions, just look
out the back of any turbojet airplane and see the difference.

Fuel cells where the heat can be used can get up to 85 percent efficiency,
but they are just now starting to come down in price. If you don't think a
fuel cell-powered mower is possible, then I won't worry you with the one I
saw at a unit of the Department of Defense in Utah.  They also have a fuel
cell-powered utility vehicle (bigger than a golf cart, smaller than an
that has an overall efficiency of somewhere in the mid-40s.  There are
for a fuel cell-powered snowmobile as well, but that is still on paper for
the time being.

For a specific comparison of fuel economy, CO, HC, and PM emissions between
2- and 4- stroke small engines, see the fourth, sixth, and seventh slides
(titled Emissions of 2-stroke vs 2-stroke Engines) in the Health and Air
Quality Impacts of Bio-based Fuels and Lubes in Small Engines slide show
http://www.deq.state.mt.us/CleanSnowmobile/montana/hpp.pdf ).  In the
slide, a comparison of CO and HC is done for two 2-stroke snowmobile
circa 1995 and 1998, a 1998 personal water craft engine, a 4-stroke engine
is a utility-type engine (a bit bigger, but not unlike a lawn mower), and
advanced 4-stroke engine (with emission controls similar to an automotive
engine).  The sixth slide down compares fuel consumption, and the seventh
illustrates particulate matter emissions.  The data were all developed at
Southwest Research Institute, some of which was paid for by this

Information on cleaning up these small engines also on the web site
(www.deq.state.mt.us\cleansnowmobile or www.cleansnowmobilefacts.org .
by using an ethanol blend fuel and low emissions lube oil in a two-stroke
engine, we measured reductions of CO by 9 to 38 percent, HC reductions of
to 27 percent, and particulate matter reductions of 25 to 70 percent.  NOx
was not affected, and NOx emissions from 2-stroke engines are low-so low
that they produce ammonia.  A number of colleges have also been looking
cleaning up and quieting down 2-stroke engines as illustrated in the
from the SAE Clean Snowmobile Challenge (also on the web site).  Catalytic
converts are available and used (in Europe, Asia, and some places here) for
engines as small as chain saws.  It would not be a problem to put one on a
lawn mower.

I suspect many on the P2Tech list will not have to worry about snowmobile
emissions, but the same principles apply to jet skis, personal watercraft,
small marine engines, and ATVs.  This site represents over $1 million in
research done in or for the greater Yellowstone (as in National Park)

Back to the first topic of keeping the area around buildings trimmed in a
acceptable (pollution-prevention) method.

I would suggest a more efficient way to keep the grass short-use a drought
resistant grass variety (like buffalo grass) and/or your neighbors' horses
(or sheep) to periodically mow it.  I also limit watering.  If I don't
water, I don't have to mow here in Montana. I keep it dry enough to where
dandelions don't grow, but it stays green to keep the dust down. I know
some places in this country it rains (Seattle, WA, Beaumont TX, New Jersey,
New York, Michigan), so other methods might be needed.  Like possibly not
growing any grass at all: put in a vegetable garden with mulch, or do
something a bit more natural.

This was less than 15 minutes of thought/typing, and I apologize if it was
boring.  Just know that someone has been working on the problem of 2-stroke
engine emissions because once you are out the U. S., almost all the
use either diesel or 2-stroke engines.

Howard Haines
Bioenergy Engineering Specialist
Montana Department of Environmental Quality