~ ~ Intro to Thermoelectrics ~ ~

Hot

Cold

+

+-

Thermoelectric Effects

S=Voltage response per T [V/K]

n

Hot

Cold

VOC

+p

Seebeck Coeff, S

TSSV npOC

Thermocouple

Thermoelectric Effects

I

n

Hot

Cold

Load

+I I

I

p

Power Generation

S=Voltage response per T [V/K]

n

Hot

Cold

VOC

+p

Seebeck Coeff, S

TSSV npOC

Thermocouple

Thermoelectric Effects

I

n

Hot

Cold

Load

+I I

I

p

Power Generation

S=Voltage response per T [V/K]

n

Hot

Cold

VOC

+p

Seebeck Coeff, S

TSSV npOC

Thermocouple

I

n

Hot

Cold

Power

Supply

+I I

I

p

IQ np

Refrigeration

ST Peltier Coeff, = Heat removed per charge [J/C]

/T = S =Entropy per charge [J/K per C]

Characteristics of TED Performance

k

TSZT

2

Seebeck Coeff.(~heat carried per charge)

electrical conductivity

thermal conductivity(heat leakage)

Figure of Merit

0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5

Eff

icie

ncy

Efficiency as Heat Engine

Th=600 C,

Tc=20C

ZT

Eff

icie

ncy

Hot

Cold

Load

+

Energy Flows in the US

EIA / LLNL

Units of ExaJoules / yr: 1 EJ = 1018 J.

Fossils:

Global

Warming

Total: 3.2 x 1012 W

54 kg of CO2

per person-day

1.0 GJ per person-day

Imports: Security5.4 L of oil per person-day

38%

effic.

Thermoelectric ApplicationsPower GenerationTemperature Control

Space Probe: long life

PCR

Optoelectronics (Melcor)

Fairbanks (DEER2006)

Energy Scavenging...?

"Climate Controlled Seat" (Amerigon / BSST)

Two BMW images from Jeff Snyder's website.

Energy Flows in a Car

Energy Flows in a Car

Urban cycle 30 mph avg, 22 mpg. Fueleconomy.gov; F. Stabler, GM. DOE Thermoelectrics Workshop 2004.

Radiator

Com

bu

stio

n

TH

450 - 650 C

40%

30%

25%

5%

12.5 kW

Engine

=30%

Gasoline

50 kW

Driveline Losses

Propulsion &Accessories

15 kW

2.5 kW12.5 kW

22 mpg

Exhaust Gas

20 kW

Energy Flows in a Car

Exhaust Gas

Radiator

Driveline Losses

Engine

=30%

Com

bu

stio

nGasoline

50 kW

20 kW

15 kW

2.5 kW

30%

25%

5%37.9 kW

11.4 kW

1.9 kW

3.0 kW

9.5 kW

40%

TE Waste Heat Scavenging

=20%

12.2 kW

Propulsion &Accessories

12.5 kW

22 mpg

29 mpgTH

450 - 650 C