Natural gas vehicles (NGVs) are a viable alternative to gasoline and diesel vehicles. NGVs have environmental advantages as natural gas produces less greenhouse gases and other emissions than gasoline or diesel. They also have safety advantages as natural gas is lighter than air and dissipates quickly when released. There are economic advantages to NGVs as well, as natural gas prices have remained stable while gasoline and diesel prices have fluctuated significantly. With tax incentives, fleets can see a payback period of 2-4 years by switching to NGVs. CenterPoint Energy offers compressed and liquefied natural gas fueling options in Minnesota.

1. Minnesota Energy Efficiency & Load
Management Symposium
Natural Gas Vehicles (NGV’s)
Dave Poretti
CenterPoint Energy
October 12, 2012 1

2. Overview
• Natural gas as a transportation fuel - Why consider NGV’s?
• Environmental advantages
• Safety advantages
• CNG (Compressed Natural Gas) and LNG (Liquefied Natural Gas)
• Natural gas supplies and shale gas impacts on supply
• Economic advantages over other fuels
• Tax credits
• CenterPoint Energy CNG & LNG availability in Minnesota
• Summary
• Questions
2

3. Why consider NGVs?
• Proven technology
• Take control of your fleet’s fuel costs
• Minimize the impact of out of control oil prices
• Stable natural gas prices
• Save up to $2 per gallon from gasoline or diesel
• Potential paybacks in the 2-4 year range without
incentives
3

4. Natural Gas as a Transportation Fuel
Natural Gas is:
• Domestic
• Abundant
• Economical
• Clean
• Safe
4

5. Environmental Advantages
Natural gas is cleaner than other fuels
Natural gas compared to diesel and other fuels
• Natural gas is mostly methane: Methane - CH4
• Diesel –C14H30
• Gasoline –C8H18
• Propane –C3H8
• Less Nox (85% less smog) and soot than petroleum fuels
Natural gas produces less greenhouse gases than
diesel
• Heavy Duty Vehicles (HDV’s) about 20-23%
• Light Duty Vehicles (LDV’s) about 26-29%
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6. Safety Advantages
Natural gas is very safe
• Lighter than air… dissipates when released
• High ignition temperature: 1000-1100F
• Limited range of air/fuel combustion ratio (5-15%)
• Doesn’t leak into groundwater and no spills from dispensing nozzle
• Comprehensive fuel tank, vehicle and station design/mfg codes &
standards
• Onboard storage cylinders are manufactured to a higher standard
than those made for gasoline/diesel vehicles
• Maintenance buildings will have to be modified to maintain NGVs
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7. Facts About Natural Gas
Compressed Natural Gas (CNG)
• Gas delivered to site by the local gas utility and compressed
and stored onsite and/or distributed directly to vehicles
• Onboard 3,600 psi vehicle cylinders
• CNG is measured in Gasoline Gallon Equivalents
• NGVs are proven and reliable (11,000+ transit buses and
4,000 + refuse trucks. Cummins Westport has 10,000 +
natural gas engines in the field.)
• NGVs are quiet (80-90% lower decibel level than diesel)
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8. Typical Natural Gas Compressor Station
How it works
• The natural gas enters the compressor station going through the dryer to the
compressor.
• If a slow fill system, no storage is required.
• If Fast Fill, storage is required.
• To the dispensing equipment into a NGV.
• Stations can range from $5,000 for an individual homeowner unit to several
million dollars. The price is dependent upon number of vehicles to fuel, number
of gallons per hour and if storage is required.
Information
Needed:
• # Vehicles
• Miles per Gallon
• Gallons per Day
• Timeliness of
Refueling and
time of day Flow
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9. Liquefied Natural Gas (LNG) Facts
• Natural Gas cryogenically cooled to liquid @ (-260 Degree)F,
stored in liquid form onboard vehicle and vaporized back to a
gas before it enters engine cylinder. Natural gas replaces the
energy (Btu’s) in gasoline or diesel with the energy (Btu’s) in
natural gas.
• Preferred by many heavy-duty fleets due to its higher energy
density and space requirements
• Most vehicular LNG used today is produced at a limited
number of plants and trucked to fleets’ onsite storage vessels.
• Transportation of LNG to the fueling location is a
consideration.
9

10. Typical LNG Station
How it works
• LNG is stored in the Storage
vessel.
• Upon Demand, LNG is pumped
to the dispenser using a cryogenic
pump into a NGV.
• LNG Stations vary in price based
on the amount of fuel dispensed
per hour and the amount of storage
Flow
on-site. The prices range from several
hundred thousand to several million
dollars.
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11. Natural Gas Supply- Short & Long Term
• Inventories are at record levels compared to both year-ago levels and
5 year levels.
• Average wellhead prices are predicted to remain low for the
foreseeable future due to the extensive shale gas resources.
• Natural gas produced from shale currently accounts for 23% of
domestic production and is forecasted continue to grow.
• As a result of the increased supply from shale gas, it is estimated that
there is over 100 years of supply at 2010 usage levels.
Source: EIA AEO 2012 Early Release, the Potential Gas Committee
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12. Where is the Shale Gas?
Groundwater aquifers Private well, about 500 ft deep
Public well, about 1,000 ft deep
Several layers of steel tubes
encased in cement protect
groundwater supplies
Protective steel casing
encased in cement extends to
shale depth
Fracking depth from the
surface is typically more than
1.5 miles (7,700 ft. ave.) and
1+ miles below the depth of
public wells.
For a video detailing the shale hydraulic fracking process, visit:
http://www.hydraulicfracturing.com/Pages/information.aspx 12

13. Economic Advantages
Price Stability Compared to Diesel
Price of Gas Delivery Electricity Compressor Capital Federal & Total DGE
Natural Gas Commodity Cost DGE Cost DGE Maintenance Amortization State Fuel
per Dth Cost Note 2 Note 3 Cost DGE Cost DGE Tax
DGE Note 1 Note 4 Note 5 Cost DGE
Note 6
$2.89 $0.401 $0.1994 $0.13 $0.30 $0.50 $0.524 $2.0544
$3.00 $0.417 $0.1994 $0.13 $0.30 $0.50 $0.524 $2.0704
$4.00 $0.56 $0.1994 $0.13 $0.30 $0.50 $0.524 $2.2134
$ 5.00 $0.70 $0.1994 $0.13 $0.30 $0.50 $0.524 $2.3534
$ 6.00 $0.83 $0.1994 $0.13 $0.30 $0.50 $0.524 $2.4834
$ 7.50 $1.04 $0.1994 $0.13 $0.30 $0.50 $0.524 $2.6934
$ 10.00 $1.39 $0.1994 $0.13 $0.30 $0.50 $0.524 $3.0434
$12.50 $1.74 $0.1994 $0.13 $0.30 $0.50 $0.524 $3.3934
$15.00 $2.09 $0.1994 $0.13 $0.30 $0.50 $0.524 $3.7434
1. September 2012 CenterPoint Energy WACOG of $2.8948/Dth / 7.194
2. September 2012 Firm C Delivery Charge of $1.4343 per Dth / 7.194
3. Per NGV America. Includes Kwh + demand
4. Per NGV America
5. Per NGV America
6. Federal and State Excise Tax Diesel ($0.244 Federal + $0.28 State) 13

14. Economic Advantages
Price Stability Compared to Gasoline
Price of Gas Delivery Electricity Compressor Capital Federal & Total GGE
Natural Gas Commodity Cost GGE Cost GGE Maintenance Amortization State Fuel Tax
per Dth Cost Note 2 Note 3 Cost GGE Cost GGE Cost GGE
GGE Note 1 Note 4 Note 5 Note 6
$2.89 $0.362 $0.1793 $0.12 $0.27 $0.45 $0.464 $1.8453
$3.00 $0.375 $0.1793 $0.12 $0.27 $0.45 $0.464 $1.8583
$4.00 $0.50 $0.1793 $0.12 $0. 27 $0.45 $0.464 $1.9833
$5.00 $0.625 $0.1793 $0.12 $0. 27 $0.45 $0.464 $2.1083
$6.00 $0.75 $0.1793 $0.12 $0. 27 $0.45 $0.464 $2.2333
$7.50 $0.9375 $0.1793 $0.12 $0.27 $0.45 $0.464 $2.4208
$10.00 $1.25 $0.1793 $0.12 $0.27 $0.45 $0.464 $2.7333
$12.50 $1.5625 $0.1793 $0.12 $0.27 $0.45 $0.464 $3.0458
$15.00 $1.875 $0.1793 $0.12 $0.27 $0.45 $0.464 $3.3583
1. September 2012 CenterPoint Energy WACOG of $2.8948/Dth / 8
2. September 2012 CenterPoint Energy Firm C Delivery Charge of $1.4343 per Dth / 8
3. Per NGV America. Includes Kwh + demand
4. Per NGV America
5. Per NGV America
6. Federal and State Excise Tax Gasoline ($0.184 Federal + $0.28 State)
14

15. NGV Tax Incentives
• Bonus depreciation allows 50 percent depreciation for 2012
expenditures
• New Legislation
• Natural Gas Act 2011- Currently 180+ co-sponsors
15

16. Key NGV Considerations
• Retrofitting garage for maintenance of
vehicles
• Compression facilities properly sized
• Purchase of new dedicated natural gas
vehicles
• Retrofitting existing vehicles
16

17. CenterPoint Energy CNG & LNG
Availability in Minnesota
Public CNG Station
Hours M-F 7:30 am to 6:00 pm
501 West 61st Street
Minneapolis, MN 55419
LNG Tanker Loads
11500 12th Avenue South
Burnsville, MN 55337
If you are interested in purchasing CNG or LNG from either of the
above facilities, please contact Jon Williams, 612-321-4390 or 612-
321-4330.
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18. Summary - Why Look at NGV’s
• Proven technology
• Take control of your fleet’s fuel costs
• Minimize the impact of out of control oil prices
• Stable natural gas prices
• Easily save up to $2 per gallon from gasoline or diesel
• Potential paybacks in the 2-4 year range without
incentives
18

19. Where do we start?
X
Infrastructure Vehicles
X=Both infrastructure and vehicles need to be worked
on at the same time for NGV’s to succeed!
19

20. Questions?
Contact:
CenterPoint Energy, Energy Sales
(612) 321-4330, 800-234-5800, ext. 4330
CenterPointEnergy.com/NGV
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21. Appendix-Conversions
Conversions from commodity to GGE or DGE:
• One cubic foot = ~1,000 BTUs (Note: cf = volume, BTU = energy)
• One Dth = 1,000 cubic feet
• One Dth = 1,000x1,000 = ~1,000,000 Btus (MMBtu or dekatherm)
• One Gasoline Gallon Equivalent (GGE) is 125,000 Btu/GGE …therefore….
• One Dth = roughly 8 GGE of (uncompressed) natural gas.
• One Diesel Gallon Equivalent (DGE) is 139,000Btu/DGE ….therefore....
• One Dth = roughly 7.194 DGE of (uncompressed) natural gas
Fuel Unit of Measure BTU Content Natural Gas Dth
Conversion
Natural Gas Dth 1,000,000
CNG GGE 125,000 8.00
LNG Gallon 82,644 12.1
Propane Gallon 91,600 10.917
Gasoline Gallon 125,000 8.00
Diesel Gallon 139,000 7.194
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