Thermoelectric Generator

 A thermoelectric generator (TEG) is a device that converts heat directly into electricity using the Seebeck effect.

When one side of the module is hot and the other side is cold, it generates DC voltage.

How It Works

• Hot side: receives heat (exhaust gas, burner, engine, steam pipe, etc.)
• Cold side: cooled by air or water
• Temperature difference creates electron movement → electricity

Basic Formula

$$V = S \times \Delta T$$

Where:

• $V$ = generated voltage
• $S$ = Seebeck coefficient
• $\Delta T$ = temperature difference

Greater temperature difference = more power.

Main Components

1. Thermoelectric module
2. Heat source
3. Heat sink/cooling system
4. DC-DC converter/controller
5. Battery/load

Common Materials

• Bismuth Telluride (Bi₂Te₃) → low/medium temperature
• Lead Telluride
• Silicon Germanium → high temperature

Applications

Oil & Gas

• Remote pipeline CP power
• Gas metering stations
• RTU/SCADA power supply
• Offshore instruments

Automotive

• Vehicle exhaust heat recovery
• Truck auxiliary power

Industrial

• Furnace waste heat recovery
• Boiler stack heat utilization

Small Projects

• Camping stove charger
• Bike exhaust power generation
• Sensor powering

Advantages

• No moving parts
• Silent operation
• Low maintenance
• Reliable for remote locations
• Works continuously with heat source

Disadvantages

• Low efficiency (typically 3–8%)
• Requires strong temperature difference
• Heat management is critical
• TEG modules can be expensive

Real Example

A motorcycle exhaust at:

• Hot side: 250°C
• Cold side: 50°C
• Temperature difference: 200°C

A small TEG module may generate:

• 3–8 W electrical power per module

Enough for:

• USB charging
• LED lights
• Sensors

Famous Industrial TEG Systems

• Gentherm Thermoelectric Generator 1120
• Radioisotope thermoelectric generators (RTG) used in spacecraft like Voyager 1