Clean Automotive TechnologyClean Automotive TechnologyHHV Component Information 

October 16, 2011

Clean Automotive Technology ProgramOffice of Transportation and Air QualityU.S. Environmental Protection Agency

Clean Automotive Technologywww.epa.gov/otaq/technology

Working Paper No. HDH-07-11(7th HDH meeting, 12 to 14 October 2011)

BentBent‐‐Axis PumpAxis Pump‐‐Motor EfficiencyMotor EfficiencyMotor Mode at 3500 psi*Motor Mode at 3500 psi*

95%95%

90%90%

* Efficiencies at other pressures above and below 3500 psi are similar to those shown in this chart.Clean Automotive Technology ‐ US EPA

Clean Automotive Technology ‐ US EPA 3

Accumulator PerformanceCharge/Discharge Efficiency

*From a comparison of energy/efficiency tests in several 16-gallon accumulators done for EPA by Southwest Research Institute.

Accumulator Operating Efficiency*

60-second HoldAfter a 60 sec hold, typical foamed accumulators were able to retain 94% to 98%of the energy.

10-minute HoldThe best accumulator tested was able to retain 97% of the energy.

Clean Automotive Technology ‐ US EPA 4

Relative Performance of EnergyRelative Performance of Energy‐‐StorageStorage

1

2

4

6

10

2

4

6

100

2

4

6

1000Sp

ecifi

c En

ergy

(Wh/

kg)

100

101

102

103

104

Specific Power (W/kg)

Lead-acid

Capacitors

Fuel Cells

IC Engine

HEV goal

3.6 s36 s0.1 h1 h

10 h

100 h

Ni-MH

Li-ion

3.6 s36 s0.1 h1 h

10 h

100 h

Acceleration

Ran

ge

EV goal

3.6 s36 s0.1 h1 h

10 h

100 h

Source: Product data sheets

Venkat Srinivasan and John Newman; Environmental Energy Technologies Division; Lawrence Berkeley National Laboratory; Berkeley, CA

The HHV UPS truck operates

here.0.1h 36 sHydraulic Accumulators

Accumulators can operate anywhere in

the green box with infinite

life.