iee activities new materials for thermoelectrics for ... · new materials for thermoelectrics for...
TRANSCRIPT
John Bowers
iee.ucsb.edu
IEE Activities
New Materials for Thermoelectrics for
Refrigeration, Power Generation
and Waste Heat Recovery
Institute for Energy Efficiency
Innovating Global Energy Solutions
UC Santa Barbara
• Dynamics of Energy Efficiency (Buildings)
• Computing and
Networks
• Production and Storage
• Lighting and Displays
• Policy and
Economics
• Mark Manydosa, Minister of Tanzania, spoke of the need for improved
efficiency in irrigation systems.
• 400,000 hectares of irrigation needed for self sufficiency.
• Unaccounted usage was 50% in 2000, now 30%.
• The need for more efficient irrigation systems requires
– Sensors to determine hydration of soil
– Sensors to determine wafer flow, availability, and losses
– Actuators to adjust flows
– Ad hoc network between sensors, actuators and a global control and
monitoring center
– An autonomous decision making system
• Mark Manydosa, Minister of Tanzania spoke of the need for improved
efficiency in irrigation systems.
• The need for more efficient irrigation systems requires
– Sensors to determine hydration of soil
– Sensors to determine wafer flow, availability, and losses
– Actuators to adjust flows
– Ad hoc network between sensors, actuators and a global control and
monitoring center
– An autonomous decision making system
• This is similar to the requirements of more efficient buildings where one
wants to control lights or airflow.
• Where does cooled air flow, or how much and when. Sensors, actuators
and communication.
• One can build a network of solar powered sensors and actuators that
wirelessly communicate with each other and with a centralized controller,
with an intelligent program for optimization and control.
• Mark Manydosa, Minister of Tanzania spoke of the need for improved
efficiency in irrigation systems.
• The need for more efficient irrigation systems requires
– Sensors to determine hydration of soil
– Sensors to determine wafer flow, availability, and losses
– Actuators to adjust flows
– Ad hoc network between sensors, actuators and a global control and
monitoring center
– An autonomous decision making system
• This is similar to the requirements of more efficient buildings where one
wants to control lights or airflow.
• Where does cooled air flow, or how much and when. Sensors, actuators
and communication.
One can build a network of solar powered sensors and actuators that
wirelessly communicate with each other and with a centralized
controller, with an intelligent program for optimization and control.
• Dynamics of Energy
Efficiency
• Computing and
Networks
• Production and Storage
• Lighting and Displays
• Policy and
Economics
• A common problem in
developing countries is
burning kerosene for
lighting.
• This is expensive, polluting,
and hazardous to the user’s
health.
• A number of organizations
are addressing this need:
LUTW, BOGO,…
Dave Irvine-Halliday, founder of Light
Up The World, with two kerosene wick
lamps, previously the main source of
illumination in the village
• IEE is partnering with Engineers without
Borders, and Pangea to get low cost, high
quality solar powered lighting to people in
Ghana.
• Combines:
– Efficient, low cost, long lifetime LEDs
– Efficient, low cost, long lifetime batteries
– Efficient, low cost, long lifetime solar cells
• Efficient lighting for <$10. Pays for itself in 2 months.
• Dynamics of Energy
Efficiency
• Computing and
Networks
• Production and Storage
• Lighting and Displays
• Policy and
Economics
• Eliminate conventional refrigerators
• Eliminate need for refrigerants (CFCs and replacement gasses)
• Reduce energy consumption.
• Improve efficiency in solid state refrigerators.
. • A solid state thermoelectric refrigerator
could be 10 times smaller than a
conventional refrigerator.
• Longer Lifetime
• A typical refrigerator is replaced every 15 years.
• Solid state refrigerators should last 50 years.
Automotive ApplicationsHeating, cooling, waste heat recovery,
replace generator, replace internal
combustion engine (ZT>4 required).
Impact: Thermoelectrics
Relative
Efficiency
0.1
0.4
0.3
0.2
ZT
1 2 3 4
Commercial TE’s
Typical mechanical systems
ZT is a metric related to efficiency.
ZT~1 is common today.
Increasing ZT to 4 enables efficient solid
state refrigerators, efficient air
conditioning and efficient, cost effective
waste heat recovery.
Hot and cold
electrons in
equilibrium
Hot
electron
filter
0
1
2
3
4
5
6
7
8
-1
0
1
2
3
4
5
0 2 4 6 8 10 12 14
barrie
rf
B
Fermi Energy (eV)
Conserved
Non-conserved
New Concept to Optimize TE Efficiency:New Concept to Optimize TE Efficiency:(Metal/Semiconductor Nanocomposites) (Metal/Semiconductor Nanocomposites)
Even with only modestly low lattice thermal conductivity and
electron mobility of typical metals, ZT > 5 is theoretically possible
with hot electron filters
EEEEEEEEEEEEEEEEEEEEEEEEEE
ErAs nanocrystals in InGaAlAs
Many other Lanthanide elements are possible.
Power generator module fabrication:
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AAAAAEEEEEEEEEEEEEEEEmEEEEAAEEEEEEEEEEEAEEEAEEEEmEAEEE
Waste Heat Recovery or Power Generation are also possible.
(Run the refrigerator in reverse: Put in heat and take out electricity)
2015 Technology Initiatives
Zero-Net Energy Buildings and Homes
Lighting - 300Lm/W LED at the cost of a regular light bulb
Solar Cells: Double the efficiency at one-tenth the cost
1000x Faster Computing/Watt
Thought Leadership Initiatives
Distinguished Fellows Program
International Conferences
IEE INITIATIVES