energy-harvesting thermoelectric sensing for unobtrusive water … · 2014. 11. 17. · thermes –...
TRANSCRIPT
![Page 1: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/1.jpg)
Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water and Appliance Metering
Brad Campbell, Branden Ghena, and Prabal Dutta
2nd International Workshop on Energy Neutral Sensing Systems (ENSsys 2014) – November 6, 2014
![Page 2: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/2.jpg)
The Call for “Low Power Sensors”
“BTO [Building Technologies Office] is particularly interested in innovative approaches that reduce the cost and power consumption for data collection of common building operation variables (temperature, pressure, relative humidity, etc.)…”
2
Source(s): 1. “Building Energy Efficiency Frontiers and Incubator Technologies (BENEFIT),” DE-FOA-0001027, 2014
![Page 3: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/3.jpg)
An Energy Harvesting Architecture
The Monjolo Family – Energy-neutral system – Wireless communications
3
Light-level Plug-load Panel-mount
![Page 4: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/4.jpg)
The Monjolo Principle
Monjolo: Portuguese water hammer In an energy harvesting system:
The rate at which energy is harvested is proportional to the intensity of the
measured phenomenon
The energy harvester is the sensor
4
![Page 5: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/5.jpg)
Our System Design
Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless communication
5
![Page 6: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/6.jpg)
Thermes System Architecture
6
P
P
P
Power Supply
500μF
LTC3109
VCC
NodeCore
VCC_EN
PGOOD
2.1V
OR
![Page 7: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/7.jpg)
Thermes System Architecture
7
P
P
P
Power Supply
500μF
LTC3109
VCC
NodeCore
VCC_EN
PGOOD
2.1V
OR
![Page 8: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/8.jpg)
Thermes System Architecture
8
P
P
P
Power Supply
500μF
LTC3109
VCC
NodeCore
VCC_EN
PGOOD
2.1V
OR
![Page 9: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/9.jpg)
Thermes System Architecture
9
P
P
P
Power Supply
500μF
LTC3109
VCC
NodeCore
VCC_EN
PGOOD
2.1V
OR
![Page 10: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/10.jpg)
Harvesting Front End
Peltier junctions – Temperature differential into current – Low efficiency
Heat rejection is critical
Multiple junctions in series for more voltage
10
P
P
P
Power Supply
500μF
LTC3109
VCC
NodeCore
VCC_EN
PGOOD
2.1V
OR
![Page 11: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/11.jpg)
Zoom into Power System
Power supply – Auto-polarity – Harvesting begins at 30 mV
500 uF capacitor bank – No battery
11
Top B
ottom
P
P
P
Power Supply
500μF
LTC3109
VCC
NodeCore
VCC_EN
PGOOD
2.1V
OR
![Page 12: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/12.jpg)
Zoom into Latch Circuit
Latch sets size of “bucket” and turns the node core on and off Turns on at 3.1 V, powers down at 2.1 V
Translates to 1.3 mJ per activation
12
P
P
P
Power Supply
500μF
LTC3109
VCC
NodeCore
VCC_EN
PGOOD
2.1V
OR
![Page 13: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/13.jpg)
Transmission Rate Changes with Temperature
13
Time
Temperature Differential
Time
Radio Packet Transmission
![Page 14: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/14.jpg)
Zoom into Node Core
The classic node setup MSP430
– TinyOS
CC2420 – 802.15.4 communications
14
P
P
P
Power Supply
500μF
LTC3109
VCC
NodeCore
VCC_EN
PGOOD
2.1V
OR
Top
![Page 15: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/15.jpg)
Our System Design
Thermes Energy-Neutral Thermal Sensing But what can you do with such a sensor?
15
![Page 16: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/16.jpg)
Shower Use Is a Contributing Factor
Consumers don’t have insight into how this energy is being spent
16
Department of Energy, “Building Energy Data Book.” 2010
American Water Works Association Research Foundation, “Residential End Uses of Water.” 1999
![Page 17: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/17.jpg)
Existing Water Meters
17
![Page 18: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/18.jpg)
Acoustic Water Meters
High powered sensing – Lifetime limitation
18
Sprav Upstream
![Page 19: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/19.jpg)
Impeller-Based Water Meters
Impeller-based design – Good for energy harvesting – Difficult installation
19
Amphiro
![Page 20: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/20.jpg)
Thermal Harvesting Water Meters
Thermoelectric energy-harvesting – Energy-neutral in some cases
Accelerometer-based sensing – Increases energy needs
20
DoubleDip
![Page 21: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/21.jpg)
Applying Our Solution
This is an area for which we designed Thermes Trade accuracy and fine-grained detail
for continuous batteryless operation Shower sensing is actually very challenging for this system
21
![Page 22: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/22.jpg)
Thermes Implementations
Small Bracelet – 6 Peltier Junctions
(7 mm x 6 mm) – 9 Heatsinks
Large Bracelet
– 4 Peltier Junctions (15 mm x 15 mm)
– 4 Heatsinks
22
![Page 23: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/23.jpg)
Evaluation Criteria
1) How does it work at various water temperatures?
2) How well can it estimate start and stop times?
3) How well does it work on a real shower?
4) What other applications can it be used for?
23
![Page 24: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/24.jpg)
Evaluation Setup
Mini-shower Allows for configurable constant water temperature Ambient temperature remained 23° C for all tests
24
![Page 25: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/25.jpg)
Evaluation Setup
Mini-shower Allows for configurable constant water temperature Ambient temperature remained 23° C for all tests
25
Thermes
![Page 26: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/26.jpg)
Evaluation Criteria
1) How does it work at various water temperatures?
2) How well can it estimate start and stop times?
3) How well does it work on a real shower?
4) What other applications can it be used for?
26
![Page 27: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/27.jpg)
Operation at Average Shower Temperature
27
0
5
10
15
20
0 5 10 15 20 25 30
Act
ivatio
ns/
min
41
°C
(106
°F
)
Time (min)
Shower On Shower Off
Small Bracelet Large Bracelet
![Page 28: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/28.jpg)
Operation at Average Shower Temperature
28
0
5
10
15
20
0 5 10 15 20 25 30
Act
ivatio
ns/
min
41
°C
(106
°F
)
Time (min)
Shower On Shower Off
Small Bracelet Large Bracelet
![Page 29: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/29.jpg)
Operation at Average Shower Temperature
29
0
5
10
15
20
0 5 10 15 20 25 30
Act
ivatio
ns/
min
41
°C
(106
°F
)
Time (min)
Shower On Shower Off
Small Bracelet Large Bracelet
![Page 30: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/30.jpg)
Operation at Average Shower Temperature
30
0
5
10
15
20
0 5 10 15 20 25 30
Act
ivatio
ns/
min
41
°C
(106
°F
)
Time (min)
Shower On Shower Off
Small Bracelet Large Bracelet
![Page 31: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/31.jpg)
Equilibrium of the System
31
Time
Temperature of Pipe
Time
Radio Packet Transmission
![Page 32: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/32.jpg)
Equilibrium of the System
32
Time
Temperature of Pipe
Time
Radio Packet Transmission
![Page 33: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/33.jpg)
0
5
10
15
20
0 5 10 15 20 25 30
Act
ivatio
ns/
min
38
°C
(100
°F
)
Time (min)
Lower Temperature Operation Is Troublesome
33
Shower On Shower Off
Small Bracelet Large Bracelet
![Page 34: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/34.jpg)
0
5
10
15
20
0 5 10 15 20 25 30
Act
ivatio
ns/
min
38
°C
(100
°F
)
Time (min)
Lower Temperature Operation Is Troublesome
34
Shower On Shower Off
Small Bracelet Large Bracelet
![Page 35: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/35.jpg)
Evaluation Criteria
1) How does it work at various water temperatures?
2) How well can it estimate start and stop times?
3) How well does it work on a real shower?
4) What other applications can it be used for?
35
![Page 36: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/36.jpg)
Estimating Start and Stop Times
36
Small Bracelet
0
5
10
15
20
25
-1 0 1 2 3 4 5 6 7 8 9 10
Act
ivatio
ns/
min
Time (min)
Shower on Shower off
![Page 37: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/37.jpg)
Estimating Start and Stop Times
Determine likely delay before first packet based on initial packet rate
37 Small Bracelet
0
5
10
15
20
25
-1 0 1 2 3 4 5 6 7 8 9 10
Act
ivatio
ns/
min
Time (min)
Shower on Shower off
![Page 38: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/38.jpg)
Estimating Start and Stop Times
Look for change in steady state operation
38 Small Bracelet
0
5
10
15
20
25
-1 0 1 2 3 4 5 6 7 8 9 10
Act
ivatio
ns/
min
Time (min)
Shower on Shower off
![Page 39: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/39.jpg)
Estimation Example
Test Results – 3 second error on Start Time – 9 second error on Stop Time
39 Small Bracelet
0
5
10
15
20
25
-1 0 1 2 3 4 5 6 7 8 9 10
Act
ivatio
ns/
min
Time (min)
Shower on Shower off
Estimated on Estimated off
![Page 40: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/40.jpg)
Evaluation Criteria
1) How does it work at various water temperatures?
2) How well can it estimate start and stop times?
3) How well does it work on a real shower?
4) What other applications can it be used for?
40
![Page 41: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/41.jpg)
Real Showers
Shower started at time zero and continued for over ten minutes
41
0
2
4
6
8
10
12
0 1 2 3 4 5
Act
iva
tion
s/m
in
Time (min)
Small Bracelet
![Page 42: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/42.jpg)
0
2
4
6
8
10
12
0 1 2 3 4 5
Act
iva
tion
s/m
in
Time (min)
Small Bracelet
Real Showers
42
![Page 43: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/43.jpg)
0
2
4
6
8
10
12
0 1 2 3 4 5
Act
iva
tion
s/m
in
Time (min)
Small Bracelet
Real Showers
43
![Page 44: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/44.jpg)
0
2
4
6
8
10
12
0 1 2 3 4 5
Act
iva
tion
s/m
in
Time (min)
Small Bracelet
Real Showers
44
![Page 45: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/45.jpg)
Evaluation Criteria
1) How does it work at various water temperatures?
2) How well can it estimate start and stop times?
3) How well does it work on a real shower?
4) What other applications can it be used for?
45
![Page 46: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/46.jpg)
Extending the Idea
Thermes can be used anywhere a temperature differential exists
46
0
5
10
15
20
25
30
0 1 2 3 4 5 6 7 8 9 10
Act
ivatio
ns/
min
Time (min)
Toaster OvenRadiator
![Page 47: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/47.jpg)
Future Work
Better heat rejection
– Improved mechanical design is necessary Cost of device
– Small form factor Peltier Junctions are expensive Long-term deployment
– What kind of data can we gain from continuous data collection?
47
![Page 48: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/48.jpg)
Conclusion
Thermes Energy-neutral thermal sensing Reductionist Sensing A new tool for ubiquitous and continuous sensing
48
![Page 49: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/49.jpg)
Questions?
Brad Campbell [email protected]
Branden Ghena [email protected]
Prabal Dutta [email protected]
Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water and Appliance Metering
http://github.com/lab11/monjolo
![Page 50: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/50.jpg)
Bonus Slides
50
![Page 51: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/51.jpg)
Wired Water Meters
51
![Page 52: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/52.jpg)
View of a Single Activation
52
0 0.5
1 1.5
2 2.5
3 3.5
-20 -10 0 10 20 30 40 50 60 70 80
Vo
ltag
e (
V)
Time (ms)
VCAPVCC
0 5
10 15 20 25 30 35
Cu
rre
nt
(mA
)Init
RadioOn
Radio TX
LED
![Page 53: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/53.jpg)
Energy Harvester Performance
Activations/min are proportional to temperature
53
0
2
4
6
8
10
12
34 35 36 37 38 39 40 41 42 43 44
Act
ivatio
ns/
min
Pipe Temperature (°C)
![Page 54: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/54.jpg)
Energy Management is a Residential Problem
Energy use in the home is an important factor of total energy use Water use is a significant portion of this problem.
54
US Energy Information Administration. 2012
![Page 55: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/55.jpg)
Water Is Becoming Scarce
• “Water scarcity is among the main problems to be faced by many societies and the World in the XXIst century.” - Human Development Report 2006, UN
![Page 56: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/56.jpg)
Current Systems Fail to Maximize Usability
DoubleDip senses flow with an accelerometer – Increases energy needs
DoubleDip board is 58 cm2 (9 in2) – More obtrusive installation
These problems limit usability
56
DoubleDip
![Page 57: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/57.jpg)
DOE’s call for “open architecture sensors”
Source(s): 1. “Building Energy Efficiency Frontiers and Incubator Technologies (BENEFIT),” DE-FOA-0001027, 2014
57
“BTO [Building Technologies Office] is developing open-architecture sensors and sensor systems that easily share data to enable building operators and owners to cost effectively capture energy and cost savings through the use of new and existing control system applications. The objective is to take to market new sensors and sensor configurations that allow easy application to building operation, easy and open access to the data from the sensors, and novel application of sensor data to building management systems. BTO is particularly interested in innovative approaches that reduce the cost and power consumption for data collection of common building operation variables (temperature, pressure, relative humidity, etc.), open-source sensor packages that allow for data acquisition and transmission with increased lifespan between manual calibrations, “virtual sensors” enabled by innovative combinations of hardware and software, and easily installed “plug and play” sensor packages in which sensors would be automatically recognized by building energy management systems, in a manner similar to how conventional printers are easily recognized by an existing computer network.”
![Page 58: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/58.jpg)
Measuring energy consuming activities
58
Monjolo: A Portuguese water hammer
servicecap
servi
ce m
ast
serviceentrance
conductors
driploop
service dropconductors
splices
currenttransformers
![Page 59: Energy-Harvesting Thermoelectric Sensing for Unobtrusive Water … · 2014. 11. 17. · Thermes – Small form factor – Thermal energy-harvesting – Energy-neutral system – Wireless](https://reader035.vdocuments.us/reader035/viewer/2022071411/6106aabbe3539067525269c6/html5/thumbnails/59.jpg)
Monjolo meter realizations
59
Test board Plug-load
Panel-mount Light-level