Electricity as a Vehicle Fuel An overview of vehicle energy sources

Wisconsin Clean City's

10th Annual Green Vehicles Workshop

Hal Glenn Owner, 2G Engineering, Sun Prairie WI

Fuel Generation and Distribution Hydrocarbon (Gas, CNG, LP, ETC) rely on existing pipe lines and over the road delivery • Existing infrastructure • Nearly half of all oil used is

imported • Majority of gasoline produced in

the U.S is from gulf cost region (40%)

EV’s rely on existing power grid for their fuel • EV’s still use fuel: Electricity is

not a fuel, just a pipeline • Generation source can be

“Green” or not • EV’s, the most flexible fuel cars

there are • Lowest cost per unit energy

Where does the Midwest get is power? Yes, your EV does runs on coal! Source: World Resource Institute

The path electricity takes to get to your door

www.eia.gov

The Battery • EV’s store their energy in chemical form in batteries • Battery density is not likely to change appreciably in the near future • EV’s are approximately 80% efficient in conversion of stored energy to

miles driven • Gas vehicles are approximately 25% efficient converting their energy

to miles driven • Net real world energy usage, EV’s use 1/3rd the stored energy for the

same distance traveled • Neglects the efficiency of the generation source (Gas or Electricity)

Batteries as a ‘Fuel’ tank: Perception of Safety is Important to Future Adoption High profile battery failures such as the recent ‘Dreamliner’ incident lead to public concern over the technology

People lose perspective on what gasoline is.

• Gasoline is approximately 50 times more energy dense

• We have a history with Gasoline

• Just as batteries, when proper care is not taken, bad things happen

Anatomy of a PHEV Battery Pack Mid-pack Service Disconnect Battery Management Module

Battery Voltage/Temp sensors

Output Contactors

Battery Cooling passages

End Run Bus Bar

HV Output Leads (orange) HVIL Connector Interlock

Chevy Volt example: 288 cells, 16kWhr; 3.3kW onboard charger

3kW On-board Charger

Ted Bohn, Argonne National Laboratory

Different Types of Electric Vehicles

– Plug in Hybrid Electric Vehicle (PHEV) • Very limited electric range – small battery 5-10

kWhr • Charge power 1-3 kW

– Extended Range Electric Vehicle (EREV) • Increased electric range – medium battery

10-20 kWhr • Charge power up to 6 kW

– Battery Electric Vehicle (BEV) • All electric range – large battery >20kWhr • Charge power > 6 kW

Electric Vehicle Charging • EV’s can be refueled in the home • Onboard AC charges limit rate of charge

• Most PHEV’s have 3KW chargers • This is the net energy equivalent of 1 gallon of gas every 3 hours

• Off board DC “fast” chargers is an emerging technology • Brings back the service station model of vehicle fueling • Most BEV’s support this • > 80% of a charge achievable in less then 15 minutes • Fast chargers not practical for home installation

The Differences Between EV Charging Levels

Given all this… Why use Electric Vehicles? • Energy independence

• EV’s reduce our dependence on foreign energy

• Reduced green house gas emissions by reduced fossil fuel consumption • Yes electric cars are green(er) • The net system efficiency of an EV is 3 times greater then an IC vehicle • When factoring in the current mix of electricity generation, the electric vehicle produces approximately

½ the amount of greenhouse gases per mile

• They are cheaper to operate and their cost per mile/per unit of energy is less then traditional cars • Most EV’s boast EPA ratings over 100MPGe • Less moving parts, more reliable

Questions?