Université de Pau et des Pays de l'Adour France Laboratoire des Sciences de l’Ingénieur Appliquées à la Mécanique et au Génie Electrique (SIAME EA4581), Fédération IPRA FR2952

Thermoelectric applications Thermoelectric generators

CHAMPIER Daniel

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 1 Thermoelectric (TE) Generators TEG

convert directly a very small part of the heat moving through them into electricity exchanger exchanger Maximum Power

Dependence upon the temperature TE modules difference across the thermoelements Tsc Tsh Th Tc NS. WTMax  2 ...   2 elec 8L Heat Heat Generator sink Construction : ‘‘power factor’’ : .number of thermoelements type of TE material .cross-sectional area .length of each element.

Module efficiency Electrical power (<5%) We T 1  zT  1    . TE Tc Qh Th 1 zT Th Electronic converter efficiency, generator maximum power R  T TE .  Ts DC DC RRRHCTE Storage Battery

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 2 World total final consumption from 1971 to 2011 by fuel (Mtoe)

***Other includes geothermal, solar, wind, etc 1Toe=tonne of oil equivalent =41.8 GJ =11.6 MWh = 1 Tep (français)

International Energy Agency publication :2013 Keyworld energy statistic 3 Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 3 Gail Tverberg http://ourfiniteworld.com/2012/03/12/world-energy-consumption-since-1820-in-charts 4 Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 4 173,000 terawatts Energy is not a problem Sustainability is the problem

Ocean Thermal Energy

y I have a dream 0.005 TW.y <0.00001 TW.y 1 Billion cars with TEG a 250W TEG

Yes we can

2014 Perez Massachusetts Clean Energy Center Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 5 Roadmap for climate and energy policies

2008 European Concil new environmental targets : "three 20 targets” by 2020

.To reduce emissions of greenhouse gases by 20%. .To increase energy efficiency to save 20% of EU energy consumption .To reach 20% of renewable energy in the total energy consumption in the EU. January 2014 European Concil new environmental targets by 2030

.To reduce emissions of greenhouse gases by 40%. .To continue improvements in energy efficiency .To reach 27% of renewable energy in the total energy consumption in the EU.

6 Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 6 Some EfficiencyEfficiency in Electricity Generation 2003 Union of the electricity industry

. L’objectif « 20-20-20 » vise pour 2020 à : Diminuer de 20 % les émissions de Gaz à Effet de Serre (GES) par rapport aux missions de 1990 ; Réduire de 20 % la consommation d'énergie par le biais de l'amélioration2013 de l'efficacité énergétique; Atteindre 20 % d'énergies renouvelables dans le bouquet énergétique.

7 Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 7 The carbon footprint of Energy-Technologies

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 8 TE efficiency 50

45 We T 1  zT  1 Carnot efficiency    . ZT=3 TE Tc Qh Th 1 zT 40 ZT=2 Th ZT=1 35 ZT=0.8 ZT=0.5 30

25

20 efficiency % efficiency

15

10

5

0 0 50 100 150 200 250 300 difference of temperature Th-Tc K Thermoelectricity : no chance for big power plant Thermoelectricity has a chance only where other forms of energy production are not cost effective.

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 9 Classification of generators

• recovery of thermal energy lost: optimization of wasted heat

• production in extreme environment: sources dedicated to TEG

• decentralized power generation: renewable energy sources

• microgeneration: all heat sources are acceptable

• thermoelectric solar: energy source : the sun.

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 10 Waste heat

1 quad=2.93 1011kWh=1.055x1018J

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 11 Secteur automobile

Thermoelectric technology for automotive Waste Heat Recovery

Prototypes : - FIAT - FORD - GM - BMW - Amerigon - Renoter (Renault truck Volvo …)

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 12 Thermoelectric technology for automotive Waste Heat Recovery

Opportunity for Waste Heat Recovery with Thermoelectrics

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 13 Thermoelectric technology for automotive Waste Heat Recovery

3% efficiency mean 0.9kW Sankey diagram for diesel vehicle

light duty trucks

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 14 Economic context European Union

New CO2 emission performance standards

Emission target for passengers cars 130g/km for 2012 drastically reduced to 95g/km for 2020 Emission target for light duty trucks 175g/km for 2014 135g/km for 2020.

Fine and penalties to be paid by car manufacturers that exceed EU CO2 limits

20€ per exceeding gram starting from 2012 95€ per exceeding gram starting from 2020

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 15 Comparison Alternator - TEG

Electricity produced by alternator

Conversion efficiency from fuel chemical energy to mechanical energy  25-27% alternator efficiency from mechanical to electrical energy  60% conversion efficiency from fuel chemical energy to electrical energy  15-16%

Electricity produced by TEG

small-medium gasoline engine at motorway driving condition is characterized by a thermal power, in its exhaust gases, of 10kW at 600°C, 4-5% system conversion efficiency, which can be feasible with ZT=1-1.2 is enough to guarantee 400-500 Wel.

2 400-500Wel means 6-7g/km CO reduction (Fiat Research Center)

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 16 Automotive Requirements for a TE Generator

Requirements

•Backpressure limit in TEG •Exchanger must not disturb too much exhaust gases: pressure drops very low (tens of a few millibars).

•Temperature limit for TE materials (add bypass for exhaust gases)

•Durability test requirements

•Assembly requirements

•Control and sensor requirements

•Power conditioning (DC/DC converter)

•Recycling

•Price and Performance

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 17 Alternator Replacement by a TEG

A TEG must be able to provide necessary power ( about 3kw 220A 14V) to the vehicle under extremely challenging conditions: • Idle • City drive cycle (Start-Stop) • +50°C to -30°C ambient conditions • Full accessory loads, including current spikes • Reduce TOTAL fuel consumption, weight, and cost compared to an alternator/battery system

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 18 Ford

TEG on a Ford Fusion with 3.0L V-6 Engine

the exhaust

Half-Heusler + Bi2Te 3segmented TE elements Anticipated power: ~500 Watts (peak)

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 19 Ford Packaging for Prototype TEG

TEG

FlexCoupling

To Exhaust

Underfloor Catalyst

To Exhaust

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 20 FORD

C. Maranville “ Thermoelectric opportunities for light-duty vehicles.” Ford Motor Company 2012

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 21 FORD : TEG performances for a 100km/h cruise

Temperature of gas

105km/h

Welec

A bypass is necessary to protect the TEG

Anticipated power: ~500 Watts (peak) !!!

C. Maranville “ Thermoelectric opportunities for light-duty vehicles.” Ford Motor Company 2012

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 22 General Motor

2011Meisner advanced thermoelectric material and generator technology for automotive waste heat at GM.pdf

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 23 GM project may 2011

General Motors Thermoelectric Generator

Vehicle Selection : Chevy Suburban This module could capture waste heat in car's exhaust and convert it to energy, improving fuel economy in a Chevy Suburban by 3%. Computer models show the device could generate 350 to 600 watts for city and highway driving, respectively.

Finalize design of prototype TEG by-pass valve set point temperature only Bi2Te3 modules for the heat exchanger is about 250°C.

2011Meisner advanced thermoelectric material and generator technology for automotive waste heat at GM.pdf Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 24 GM : Instrumented TEG and Results

150°C

Temperature of the heat exchanger is 250°C for a temperature of exhaust gas around 400°C

2011Meisner advanced thermoelectric material and generator technology for automotive waste heat at GM.pdf

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 25 GM : Instrumented TEG and Results 11 W avec un HiZ20

150°C

50°C Coolant

1,3 W avec Temperature variation along the Teg // un HiZ20 to the exhaust gas flow is significant 209$ !!!! Front 250° Middle 178° Rear 148° Temperature variation transverse to the exhaust gas flow is low < 3°C

2011Meisner advanced thermoelectric material and generator technology for automotive waste heat at GM.pdf

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 26 GM : Instrumented TEG and Results

Computer models show the device could generate 350 to 600 watts

Open circuit voltage are consistent with a 50°C smaller ΔT than measured between the heat exchanger and the coolant

2011Meisner advanced thermoelectric material and generator technology for automotive waste heat at GM.pdf

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 27 GM : future work

Improved skutterudite TE materials Refine TEG design :thermal and electrical interface, bonding … Electrical power conditioning (avoid impedance mismatch)

First experiment 19W with few modules and small ΔT extrapolated to 235 Watts in optimum conditions

Expected Output power 425 Watts !

G. P. Meisner, “Skutterudite thermoelectric generator for automotive waste heat recovery,” in 3rd Thermoelectrics Applications Workshop 2012

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 28 BMW

BMW 2008

PbTe

Bi2Te3

Bi2Te3 BMW 535i (US)

Bi2Te3TEG (2007) High-temperature TEG Pmax=300W (2009)

2012 Boris Mazar State of the Art Prototype Vehicle with a Thermoelectric Generator

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 29 BMW

BMW 2008

BMW 535i (US)

Bi2Te3TEG (2007)

High-temperature TEG Pmax=300W (2009)

2011 Dr. Andreas Eder Efficient and Dynamic –The BMW Group Roadmap for the Application of Thermoelectric Generators

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 30 Possibles locations for TEG

Integration in the exhaust system: Advantages •Highest recuperation potential Disadvantages •Exchangers : high integration effort •Connection to cooling system •Bypass : (flat possible but expensive)

Integration into the EGR (Exhaust Gas Exhaust Gas Recirculation reduces Recirculation) for a diesel engine: NOx emissions by reducing the Advantages combustion temperature in Diesel engines. Easier to integrate (existing exchanger) EGR works by recirculating a portion Control for mass flow (EGR valve) of an engine's exhaust gas back to Cooling water already there the engine cylinders. Gas must be cooled Disadvantages Reduced recuperation potential (5 à 35%)

A. Eder, BMW group, thermoelectrics applications 2011

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 31 BMW

The EGR-TEG unit consists of a TEG section and a conventional cooler section.

conventional cooler section.

TEG section

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 32 Renault Trucks, Volvo … Projet RENOTER “Récupération d'ENergie à l'échappement d'un mOteur par ThERmoélectricité”

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 33 Renault Trucks, Volvo

Choice of Silicide's

- N-type : Mg2Si - P-type : MnSi1.77

Successful lab. production of the legs for Advantages disadvantages the project prototype Non-toxic materials Moderate ZT

Light density (2-4) Mg2Si type P not available

Abundant raw materials Current doping of Mg2Si in project Support high exhaust P and N have different temperature (> 600°C) mechanical properties

2012 Luc Aixala RENOTER project presentation

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 34 Renault Trucks Joint Company -Volvo Group

•original Design of TEG compatible with different TE materials

•aim 1kW (Truck) and 300W (car) possible this year (2011) Results 350W 250W

Renoter2 10 000 cars equipped for 2018 100 000 for 2020

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 35 HeatReCar first light commercial vehicule equipped with a TEG

Vehicle

IVECO Daily, 2.3l Diesel engine

Design reference condition Vehicle @130kph Exhaust gas temperature: 450°C Gas flow : 70g/s (max torque), 140g/s (full load)

Target performance TEG electrical output 1kW

D. Magneto 3rd International Conference Thermal Management for EV/HEV Darmstadt 24-26 June 2013

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 36 HeatReCar first light commercial vehicule equipped with a TEG

Cross Flow architecture.

Material considered •TAGS •Segmented Bi2Te3-PTe •Skutterudites: developed and manufactured at Module level •Bi2Te3: used for the full scale prototype manufacturing with specific Module design

16 x 16 mm

D. Magneto 3rd International Conference Thermal Management for EV/HEV Darmstadt 24-26 June 2013

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 37 HeatReCar first light commercial vehicule equipped with a TEG

Air tank inlet . TEG architecture.

By pass valve Water tank Water tank Air tank outlet

Core size 500x100x100mm

Core weight 4kg

D. Magneto 3rd International Conference Thermal Management for EV/HEV Darmstadt 24-26 June 2013

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 38 HeatReCar first light commercial vehicule equipped with a TEG

TEG performances on the test bench Hot gaz flow: 90g/s Cold liquid flow: 1200l/h U: 32.1V ΔP hot gaz: 30mbar ΔP liquid flow: 0.15 bar I : 15A T hot gaz: 450°C T cold flow 60°C P: 482W

D. Magneto 3rd International Conference Thermal Management for EV/HEV Darmstadt 24-26 June 2013

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 39 HeatReCar first light commercial vehicule equipped with a TEG

the WLTP test is expected to replace the European NEDC procedure for testing of light-duty vehicles

www.dieselnet.com/standards/cycles/wltp.php

On board vehicle results summary TEG on board installation •Cycle NEDC, the TEG electric output is provided mainly in the extraurban part of the Cycle. •Cycle WLTP, the System reached a peak of about 220 W. •In the last part of WLTC TEG power is sufficient to provide the on-board electric need, thus completely replacing the alternator • 4% fuel economy improvement over the WLTP cycle has been achieved

D. Magneto 3rd International Conference Thermal Management for EV/HEV Darmstadt 24-26 June 2013

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 40 GENTHERM ex AMERIGON ex BSST + BMW et Ford

Cylindrical TEG

TEGs were installed in a BMW X6 and a Ford Lincoln MKT with at least 450W of power output achieved in road tests for both vehicles.

D. Crane, “Thermoelectric generator performance for passenger vehicles” 2012

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 41 GENTHERM ex AMERIGON ex BSST + BMW et Ford

ceramic Hot Exhaust honeycomb gas

Hot side shunt

cooling fluid

cold side shunt Bell, L.E. and Crane, D.T. and LaGrandeur, J. and van Heerden, D, Thermoelectric-based power generation systems and methods, US Patent App. 12/843,804 Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 42 AMERIGON BSST (BMW et Ford)

Hot side Larger area Tenneco’s booth at the 2013 Frankfurt IAA Motor Show Best exchange Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 43 AMERIGON BSST (BMW et Ford)

Tenneco’s booth at the 2013 Frankfurt IAA Motor Show

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 44 Aircraft Thermoelectric Applications How can Thermoelectric Contribute? Aircraft engine waste heat harvesting has large potential payoffs

Turboprop Turboshaft Turbofan Turbine à gaz + hélice Turbine à gaz + arbre de transmission Moteur à réaction

Advantages Disadvantages •Provides electrical power from waste heat – no fuel •New technology and unproven burn and no moving parts •Cost & efficiency; further development is needed • Operates over the entire aircraft flight envelope •Power output limited by available waste heat, space, • Operates independent of engines and does not device efficiency. affect engine operations

Fuel Reduction Watt per kilo? Preliminary analysis showed that 0.5% or more fuel reduction is achievable Acceptable 0.15 kW/kg Operating Cost Reduction Tuyère adiabatique hélicoptère Average monthly fuel costs for U.S. commercial planes is $2.415B for the first 4 months of 2009 (Source: EIA) Champier : 0.04kW/kg A 0.5% fuel reduction : $12M monthly operating cost reduction 2009 James Huang,Boeing Research & Technology Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 45 Usage of Thermoelectric Generators on Ships

.Ship transport generates a large amount of waste heat Wasted heat used for heating of heavy fuel oil . main engine (8-15 MW) •Heating of accommodation areas (heavy fuel oil) •freshwater generation

. auxiliary engines Work intermittently

. incinerator (waste oil : sludge representing 2% of oil Working time : 12h to 20h /day consumption of the main engine)

Steam engine : . Workers at heavy cost . Needs a worker at Thermoelectric start and stop : heavy . Cold sink between 5°C and 28°C genrator cost available (seawater)

. no problem with space and weight

Kristiansen : incinerator 850kW, calculation : 38kW electric cost 2,7US$/W.

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 46 Usage of Thermoelectric Generators on Ships

Significant potential:

powerful engines Cold source available The weight is not a constraint costly maintenance

Use of the systems developed for the automotive or aircraft without weight constraints.

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 47 Waste heat recovery : conclusion

Automotive Alternator + TEG : imminent Replacement of alternator : challenge

Airplanes More research is necessary …

ships Promising

Car 20€/kg Pizza 30€/kg!

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 48 Electricity production in extreme environment critical applications:

. a power source extremely reliable over very long periods.

.extreme climatic conditions: • very hot • very cold • very wet • very dry.

. Maintenance as low as possible • helicopter access •several hour trip

.Maintenance does not exist in the case of space expeditions.

. operation in a vacuum

. vibrations.

. insensitive to radiation The cost of watt is not essential

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 49 Space applications

First use of a thermoelectric generator (Pb -Te) : 1961 navigation satellite Transit (1961) of the U.S. Navy. SNAP-3 (Space Nuclear Auxiliary Power) Electrical power~2,7 watts worked for more than fifteen years

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 50 Space applications

RTG Radioisotope Thermoelectric Generator

Radioisotope Thermoelectric Generators, or RTGs convert the heat generated by 238 the decay of plutonium-238 (plutonium dioxyde PuO2) fuel into electricity using devices called thermocouples.

238Pu fuel pellet

GPHS : General Purpose Heat Source module

http://solarsystem.nasa.gov/rps/rtg.cfm

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 51 Space applications

T. Caillat et al 23rd rd Symposium on Space Nuclear Power and Propulsion STAIF 2006Jet Propulsion Laboratory/California Institute of Technology

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 52 Space applications

T. Caillat et al 23rd rd Symposium on Space Nuclear Power and Propulsion STAIF 2006 Jet Propulsion Laboratory/California Institute of Technology

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 53 Space applications

Cassini’ RTG before mounting

http://solarsystem.nasa.gov/rps/rtg.cfm

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 54 Space applications

Curiosity’s Radioisotope Thermoelectric Generator

http://solarsystem.nasa.gov/rps/rtg.cfm

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 55 Space applications

Electric Power Radioisotope Thermoelectric at beginning Numbe design Mission destination year lifetime Generator RTG of mission per r of RTG lifetime RTG Space Nuclear Auxiliary 2,7 Watts 1 Transit Navigation satellite 1961 15 years Power SNAP-3 PbTe SNAP-19B RTG PbTe-Tags 28.2 Watts 2 Nimbus III meteorological satellite 1969 2 Viking 1 Mars landers 1975 90 days 6 years SNAP-19 RTG 42.6 Watts 2 Viking 2 Mars landers 1975 90 days 4 years PbTe-Tags 4 Pioneer 10 Jupiter, asteroid belt 1972 5 years 30 years 40.3 Watts 4 Pioneer 11 Jupiter Saturn 1973 5 years 22 years SNAP-27 RTG Apollo 12, 14, 1969- 70 Watts Lunar Surface 2 years 5-8 years PbSnTe 15, 16 , 17 72 Multi-Hundred Watt (MHW) still operating 158 Watts 3 Voyager 1 & 2 edge of solar system 1977 RTG SiGe over 30 years 2 Galileo Jupiter 1989 14 years still operating 3 Cassini Saturn 1997 General Purpose Heat Source after 14 years (GPHS) RTG 292 Watts SiGe 1 Ulysses Jupiter 1990 21 years still operating 1 New Horizons Pluto, Kuiper Belt 2006 after 6 years Multi-Mission Radioisotope Mars Surface Expected 14 Thermoelectric Generator 110 Watts 1 Curiosity 2011 5 Aug 2012 years MMRTG PbTe-Tags

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 56 Space applications

Conclusion

Radioisotope Thermoelectric Generator

• compact • Continuous power sources • Used in deep space for several decades • reliable • Use nuclear fuel relatively easy to manipulate Curium-244 and Plutonium-238 • Materials used: PbSnTe, PbTe, TAGS, SiGe

Current research:

Improved performance of materials: reduced thermal conductivity of the network Zintl, skutterudites, couples segmented.

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 57 Remote Power Solutions

REJECTED HEAT Oil or gas pipelines Well sites Offshore platforms EXHAUST T F OUT Telecommunications sites E L G Communications systems A

M …. COOLING E FINS 500 Watts 24 Volts Natural Gas 48m3/day Propane 76L/day or 38kg/day Propane 38kg/day FUEL IN Energy per day= 1900MJ=527kW.h Heating Value 50MJ/kg Efficiency : 2.2 % Energy per day= 12 kW.h LOAD 500 W electric

Critical application requiring highly reliable power Low maintenance required Long life April 1, 2014 Extreme climatic conditions (hot, cold, wet, dry) Remote locations

Engine generator: efficiency 16 % and price …!

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 58 Remote Power Solutions

Critical application requiring highly reliable power Low maintenance required Long life Extreme climatic conditions (hot, cold, wet, dry) Remote location Telecommunications:50 watts 500 Watts 24 Volts helicopter access only, Natural Gas 48m3/day emergency communications system - Rocky Mountains, Canada Niche market for TEG Propane 76L/day or 38kg/day

Pipeline: 5000 watts for SCADA communications and cathodic protection of gas pipeline - India Off shore: 200 watts communications and safety Pipeline: 550 watts equipement, multiple systems communications system - Thailand 59 Daniel CHAMPIER applications de la thermoélectricitéAndes Mountains, GDR Chile Thermoélectricité 2014 Remote Power Solutions

Maximum Power for an electrical load between 0.4 and 0.9 ohm

electrical output of a Model 5060 TEG

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 60 Decentralized electricity generation

Developing countries Biomass primary energy source (cooking, heating, domestic hot water)

Developed countries Connection to the network is not always economically attractive

Biomass stoves Combined Heat and Power (CHP)

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 61 Thermoelectric power generator for Biomass Stoves 1.2 billion people without electricity in developing countries • Biomass energy is used for basic needs : cooking and heating • They needs electricity for light, cellular phone and radio

• Biomass is burnt through open fire stoves – low efficiency  forest destruction and global warming contribution – high emissions of air pollutants  health damaging

• “Planète Bois” is developing an improved multifunction biomass fired stove.  combustion chamber is designed to achieve almost complete combustion of wood  A fan is necessary to increase the air/fuel ratio  Smoke can be extracted with a horizontal pipe avoiding the building of a vertical chimney

• Connecting these households to the power grid  cost of building new landlines from US$300 to more than US$4000  cost of distribution of electricity from US$0.07 to US$5.1 per kWh

• thermoelectric generators are cost-effective options for these specific off-grid households.

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 62 Review of thermoelectric generators for cooking stoves

Heat source : hot gas Bismuth Tellurid (Bi2Te 3)

Author Heat sink (cold side) Type of module * Power per module Nuwayhid 2003 Natural air cooling Peltier 1W Nuwayhid 2005 Natural air cooling Seebeck 4.2W Nuwayhid 2005 Heat pipes cooling Seebeck 3.4W Lertsatitthanakorn 2007 Natural air cooling Seebeck 2.4 W Mastbergen 2007 Forced air cooling (1W) Seebeck + 4W regulated

“BioLite” 2009 Forced air cooling (1W) Seebeck + 2 W Champier “TEGBioS “ 2009 Water cooling Seebeck 5W

Champier “TEGBioS II“ 2010 Water cooling Seebeck 9.5W 7.5 W regulated Rinalde 2010 Forced water cooling (?W) Seebeck 10 W

O'Shaughnessy 2014 Forced air cooling (?W) Seebeck 5.9W regulated

* Peltier : The temperature difference is limited due to the maximum temperature supported by the solder The geometry is optimized for cooling and not for power generation. * Seebeck The hot side work at a temperature as high as 300°C continuously. The geometry is optimized for power generation

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 63 Open fire vs cooking stove

Open fire very low efficiency (5-10%) emission of harmful black fumes increase pressure on natural forests Rocket stove T-LUD (Top Lid UpDraft) clean household efficiency (40%) woodstove efficiency (35%)

Planète bois 85 % global efficiency cooking stove maxi CO level of 200 g/GJ reduce the fuelwood consumption by two uses cut branches (length 40 cm, diameter between 4 and 8 cm) Simultaneous cooking of 2 dishes Important production of domestic hot water: showering, cleaning, laundry, dishes. Cumulus effect: available hot water between 2 sessions available hot water for morning ablutions. low temperature radiant heating mechanical extraction (electric fan) no chimney less expensive and easier installation

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 64 “Planète Bois” Cooking stove and TEG Electric fan

Power 6 kW Forced draft Domestic hot water 30L each 30 min TEG production Wood consumption 1,5kg per hour Smoke A) pyrolyzing chamber Outside Dimensions (L,w,h) 110x60x85 cm box B) hot incoming combustion gas Life expectancy 15 years Water D) cooking plate tank 10 kW wood consumption Average efficiencyE) water tankMore 18 thanliters 80% 2.4 kW are used in heating the water F) fan 4.5 kW are used in heating the room and inertia 0.9 kW is used for cooking

Primary air Pyrolysis Mixing zone Flaming entrance chamber (shaker) chamber Secondary air Biomass stove entrance

The idea is to put the TEG in a cogeneration system which simultaneously provides electric power and heat for the hot water

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 65 “Planète Bois” Cook stoves

Primary air entrance Secondary air entrance

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 66 TEG for stoves

Tank Wall Water

TE modules TE modules Thermocouple Aluminum Heat exchanger Water tank

Thgi2 Thgi1 Heat flow

T6 T7 T9 T8

TE module T5 T4 Tw2 T3 T2

Aluminium heat exchanger T1

Water tank Thgo

67 Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 67 Maximum Power Point Tracking Boost converter.

Water Converter Tank DC TE modules DC Heat exchanger - + Battery Hot gas

Virtual load TE THot Generator DC/DC convertor Battery + Load Iin

V Iin Iout in Ri R v Ri Pulse Width Modulation Vin Vout Virtual Load MPPT Eoc Microcontroller Eoc MC9SO8 TCold TE module

8 Tcold =50 °C 7 Maximum Thot=250° C Thot=200° C power 6 Thot=150° C point Thot=100° C V est contrôlé par le rapport cyclique dc in 5 Fraction de période pendant laquelle l’interrupteur est ouvert 4

Power Power (W) 3

Vin=Vout (1-dc)=Vbatterie (1-dc) 2

1

0 0 1 2 3 4 5 6 7 E oc/2 E oc Voltage Vin (V)

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 68 Maximum Power Point Tracking Boost converter.

Water Converter Tank DC TE modules DC Heat exchanger - + Battery Hot gas

Algorithm Perturb and Observe

Measure Iin Compare with Calculate Pin previous Pin Measure Vin

Change duty cycle Vin and Iin change

Choix correct de l’incrément de Dc Efficiency : Pin/Pmax

Measured efficiency of the MPPT algorithm 1,000

0,998

0,996

0,994

efficiency 0,992 On est sur d’être au moins à 99% de la 0,990

0,988 0 5 10 15 20 puissance max Input Power Pe Avec les pertes du convertisseur :90%

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 69 “Planète Bois” Cooking stove and TEG

Power 6 kW Domestic hot water 30L each 30 min production Wood consumption 1,5kg per hour A) pyrolyzing chamber Outside DimensionsB) hot (L,w,h) incoming combustion110x60x85 cm gas Life expectancy D) cooking plate15 years Average efficiencyE) water tankMore 18 thanliters 80% F) fan

Temperatures fluctuate a lot

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 70 “Planète Bois” Cooking stove and TEG

Power 6 kW Domestic hot water 30L each 30 min production Wood consumption 1,5kg per hour A) pyrolyzing chamber Outside DimensionsB) hot (L,w,h) incoming combustion110x60x85 cm gas Life expectancy D) cooking plate15 years Average efficiencyE) water tankMore 18 thanliters 80% F) fan Thgi2 Thgi1 Heat flow

B B A A

D C C

Aluminium heat exchanger

Water tank Tgo Output Electrical Power : 23.7 W.h Fan consumption : 15.3 W.h

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 71 TEG results.

Cycle one cooking Day 1 1h30min 2 cookings Electrical energy 23.7Wh 47,4Wh produced

Average electric Power 15.8 W

Fan consumption 15.3Wh 30,6Wh

Extra Use one phone charge 1 phone charge almost Use’s exemple* 1 hours of light 4 hours of light Major Advantage - Wood consumption divided by two - Healthy (less black fumes) - More comfort for women - low CO * Phone battery of 3.7V, 1050mAh and light consummation of 4W

Cost one sample Big quantity Aluminium 60€ 30€

electronic part 31€ 15€

TE modules 75€ x6 27€ x 6

TE generator 541€ 207€

TE generators are cost-effective solutions for off-grid households with low income.

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 72 Advantages of TEG’s

The advantages of thermoelectric generator are : .It does not need extra energy from the stove. • It will use the heat flux between the gas and the water tank • It will only convert a small part into electrical energy. .It is incorporated into the cook stove: • it requires no electrical link with the outside world, unlike solar panels, or manipulation of battery. .The maintenance is very light: • nothing is moving, • everything is inside the house, • only the battery needs to be changed at the end of its life.

.The generator produces when the stove is on, day and night in good or in rainy weather (monsoon period) unlike solar panel.

.The battery does need to be oversized as each use of the stove recharges the battery unlike solar system where you need to store energy for the cloudy days.

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 73 Somewhere in a village

TomorrowToday with TEG

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 74 thermoelectric generators for cooking stoves

Biolite

USB 2W 5V

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 75 Biolite HomeStove and CampStove

Lake Brassua (Maine) 129$

Ghana

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 76 Combined Heat and Power (CHP) with TEG Market Automatic Pellet Furnaces, especially Small Scale Combustion Units East of Europe and North-America because of unreliable Electric Power Grids

Outlook BIOENERGY 2020+ Stove with TEG 400 Boiler with TEG 400

Max: 8 kWth, 100 Wel Max: 12 kWth, 300 Wel Air cooling Water cooling

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 77 Combined Heat and Power (CHP) with TEG Decentralized production for decentralized utilization

Production of electricity during periods of high heat demand and low offer of other renewable energies: • During winter • Whilst twilight or night • During times without sun and wind TEG

• 8 plates, each with 2 modules • Positioned around flame • Heated from inside, cooled from outside Module 8cmx8cm Biomass CHP (pellets)

Fuel heat output: 10 kW Nominal electric power: 200 - 400 W BIOENERGY 2020+ Location Wieselburg 100km from Vienna !

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 78 Autonomous Gas Heaters

Heater 8kW

Thot 305°C Tcold 125°C Power 7.8W

2011 M. Codecasa Design and development of a teg cogenerator device integrated in self standing gas heaters

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 79 Energy Harvesting for Low Power Electronics Modern wireless sensor modules require only ~100 W -10mW

Take a small portion of a lost flow of ‘primary’ energy, and convert it into a small flow of USEFUL electrical energy.

Every technical process produces waste heat

Micropelt MPG-D751

Micropelt thermogenerator offers a high density of up to 100 thermoelectric leg pairs per mm2

Electrical: •Thermo-Voltage: u = 0.14 V/K TEG 5mW is enough for most microsensor •Electrical Resistance: RTEG ~ 350 •Thermal Resistance: Rth = 12,5 K/W

200 C max.

http://www.micropelt.com

4.2mmx3.3mmx1mm

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 80 Energy Harvesting for Low Power Electronics

Emerson WiHART Differential Pressure Transmitter

ABB Technology Demonstrator •Self-powered WirelessHART temperature transmitter •Fully integrated thermogenerators •Powered by Micropelt TEG & boost technology

Use heat from 15 mm pipe

Output power 3.5mw at 60°C and ambiant 25°C

http://www.micropelt.com Applications : Wireless sensors Data loggers Direct valve control Wireless pneumatic control

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 81 Energy Harvesting for Low Power Electronics

Laird technology thermobility™ wpg-1 www.nextreme.com wireless power generator

D. Samson, “Aircraft-specific thermoelectric Phase changing material

generator module, 2010 H2O

Temperature outside -20° 40 minutes of electrical power after take-off !!

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 82 Solar Thermal to Thermoelectricity Solar Thermoelectricity STEG

Heat flux through a thermoelectric leg TK100 qT 100 k 1 1052 W/m AL 0.001

k 1 W.m-1 K -1 Lm0.001

Solar insulation: ~ 1 000 W/m2

Need to concentrate heat by ~100 times

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 83 Solar Thermoelectrics

1000°C

SiGe

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 84 Solar Thermoelectrics STEG

The developed solar thermoelectric generators (STEGs) achieved a peak efficiency of 4.6% under AM1.5G (1 kW m−2) conditions. Kraemer High-performance flat-panel solar thermoelectric generators with high thermal concentration Nat mat 2011 Photovoltaic: efficiency 20 % Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 85

Design of thermoelectric generator

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 86 An example of TEG

Cold exchanger

Thermoelectric Hotmodules exchanger

Bi2Te 3 Thermonamic

87 Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 87 TEG

Thermoelectric Generator

Hot fin exchanger Cold exchanger 88 Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 88 Numerical model

• Standard equations of thermoelectricity, heat transfers

Convective exchange correlations Diagram of a half exchanger Steady state

89 Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 89 Numerical model

-Electrical equivalent model calculated for each k secondary cutting.

-All parameters are temperature dependent.

- Newton-Raphson method for convergence.

90 Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 90 Results and Experiment

500

480

460

440

420

400

T (en K) 380 T hot gas T 360 T system T TEcouple hot wall T 340 hot couple Tcold couple 320 Tcold wall 300 Tcold liquid

-0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 y (en mètres)

Puissance Puissance mesurée (W) estimée (W)

37 W 38,8 W

Daniel CHAMPIER applications de la thermoélectricité GDR Thermoélectricité 2014 91