Hello Bill.
It took a while, but I've managed to dredge up some interesting data
that I think you'll find quite compelling.
Let's start with the actual reductions in vehicle production:
http://media.corporate-ir.net/media_files/IROL/84/84530/sales_production/ProductionSchedule_0606.xls
GM Production Schedule
thousands of:
cars trucks total
3rd Qtr. 2005 423 723 1,146
3rd Qtr. 2006 400 650 1,050
The overall reduction of 96,000 vehicles represents an 8.4% reduction
from the levels of a year ago.
The reductions include 23,000 fewer cars, and 73,000 fewer trucks.
===================
The overall energy use for General Motor's North American operations
can be seen here:
http://www.gm.com/company/gmability/sustainability/reports/04/600_environment/633na_ene_.html
Sustainability Report
...In 2003, GMNA consumed 25,800 GWh of energy, a 20.5% decrease compared to 1995
...Compared to 2002, overall energy use was down 5.15%, due primarily
to aggressive implementation of energy efficiency strategies.
GMNA's target for 2005 energy consumption is 24,333 GWh.
====================
GMNA's actual breakout in terms of energy sources is provided here:
http://epa.gov/climateleaders/docs/zimmerman0505.pdf
GM North America (NA) ? 2003 Energy Consumption by Fuel
[slide #17]
GM actually has a rather interesting mix of sources.
The biggest component is natural gas, which accounts for 50.5% of their total use.
Purchased electricity is next, at 35.49% (though of course, the
electricity itself has its own energy mix, which is not detailed in
the GM documents).
Coal is about another 5%, and they even make use of landfill gas (1%)
as part of their renewable/alternatives fuels program.
====================
Their Sustainability Report also provides information on GMNA's
greenhouse gas emissions, which are largely related to energy
consumption:
http://www.gm.com/company/gmability/sustainability/reports/05/600_environment/7_seventy/670na.html
...GMNA (including the US, Canada and Mexico) emissions of CO2 in 2004
were 9.46 million metric tons, a 17.1 percent decrease from 2000
levels.
...GM U.S.... In 2004, CO2 emissions from its U.S. facilities were
8.48 million metric tons, a reduction of 27.3 percent from 1990 levels
and a reduction of 18.5 percent from 2000.
====================
GM's Canadian operations actually provide the most detailed accounting
of energy use.
Although the data is specific to Canada, it certainly seems reasonable
to suppose that the per-vehicle numbers are representative of energy
use througout North America:
http://www.ghgregistries.ca/registry/out/rf_5884_662.pdf
Action Plan Update for Manufacturing and Assembly Facilities
General Motors of Canada Limited
October 31, 2005
For the period 1990 to 2004:
? Total energy consumption has been reduced 46% from 4928 MWh to 2657 MWh.
? Energy intensity normalized to vehicle production has been reduced
by 47% for car assembly and by 28% for truck assembly.
For the period 1990 to 2004:
? Total energy consumption has been reduced 46% from 4928 MWh to 2657 MWh.
? Energy intensity normalized to vehicle production has been reduced
by 47% for car assembly and by 28% for truck assembly.
...Energy efficiency initiatives have saved over 256 million kWh and
avoided 151 kilotonnes of CO2 emissions.
...Total vehicle assembly production for the 2004 calendar year was
923,451 cars and light duty trucks.
[Here is some of the energy information normalized to per-vehicle production]
Energy Consumption and CO2 Generation Normalized to Vehicles Produced
...In 2004, automotive assembly operations accounted for 71% of GMCL?s
energy consumption.
...The energy consumption per vehicle dropped by 47% for car assembly
operations and by 28% for truck assembly, for the period 1990 through
2004. The CO2 production per vehicle dropped by 39% for car assembly
operations and by 19% for truck assembly, for the period 1990 through
2004.
Table 3.2 -- Energy and CO2 Intensity per Vehicle Produced --
indicates that the "Normalized Energy Consumption" per vehicle is 2.04
MWh per vehicle.
Similarly, CO2 emissions amount to 456 kg of carbon dioxide per vehicle.
===============
Earlier versions of the GM-Canada energy reports provide some
perspective on the energy consumption of trucks vs cars:
http://www.ghgregistries.ca/registry/out/C0662-31OCT00GM-DOC.PDF
General Motors of Canada Ltd.
Updated for 1999 - October 30, 2000
Energy Consumption Per Vehicle Produced
...Chart #2 ? Energy consumption per vehicle produced is shown in this
chart and reflects the BTU energy consumed to produce each composite
passenger and light duty truck in the period from 1990 to 1999.
The data show that energy consumption for cars and trucks is pretty
much the same; in 1999, this figure amounted to about 8 million BTU
per vehicle (which is equal to 2.34 MWh).
Cars required about 10% more energy per vehicle than trucks in 1999.
But at the same time, reductions in energy use per vehicle were
occurring more rapidly for cars then for trucks.
It seems likely that more up-to-date data would show the energy
consumption to be about equal for both types of vehicles. As noted
above, current energy consumption per vehicle has been reduced to 2.04
MWh per vehicle.
====================
So, in sum, we know the energy breakout for GMNA, and we also have the
following information:
2.04 MWh per vehicle -- energy consumption
456 kg CO@ per vehicle -- carbon dioxide emissions
96,000 vehicles -- overall reduction in production for Q3-2006
Overall, then, this leaves us with a total energy reduction of:
96,000 * 2.04 = 195,840 MWh = 195.8 GWh
and CO2 reductions of:
96,000 * 456 = 43,776,000 kg of CO2
Since GMNA's use of natural gas accounts for almost exactly half of
overall energy use, then we can anticipate that half the energy
reduction, or 97.9 Gwh, will come from reduced use of natural gas.
From the conversion terms available here:
http://www.pnl.gov/conserve-energy/terms.stm
Energy Terms/Conversions
we learn that:
1 kWh = 3413 Btus
1 MWh = 3.413 million BTUs
1 GWh = 3.413 billion BTUs
and
Natural Gas: 1 cubic foot = 1000 Btu
==========
So, 97.9 GWh of energy savings amounts to
97.9 * 3.413 = 334.13 billion BTUs
which, in turn, translates to
334.13 million cubic feet of natural gas
===============
To summarize (again), we have:
Total energy reduction of 195.8 GWh
Total CO2 reductions of 43.776 million kg of CO2
Total natural gas reduction of 334.13 million cubic feet
I trust this information fully answers your question.
However, please don't rate this answer until you have everything you
need. If you would like any additional information, just post a
Request for Clarification to let me know how I can assist you further,
and I'm at your service.
All the best,
pafalafa-ga
search strategy -- Google searches on combinations of the following terms:
GM
GMNA
"energy use"
"life cycle analysis"
sustainability |