Day 3: Energy Generation Discussion 2 Energy Harvesting Day 3: Energy Generation Discussion 2 April 17, 2013 Paul Nickelsberg Orchid Technologies Engineering and Consulting, Inc. www.orchid-tech.com

Energy Harvesting Review Energy harvesting is the process of capturing trace amounts of naturally occurring energy from various sources. Accumulating the Energy Storing the Energy Applying the Energy for Useful Purpose

Energy Generation Piezoelectric Energy Generation Thermal Energy Generation Chemical Energy Generation 3

Piezoelectric Energy Generation 4

Piezoelectric Energy Generation Applying mechanical strain to certain solid materials results in energy generation. Courtesy Linear Technologies Corporation 5

Piezoelectric Energy Generation Bending motion causes upper element to compress and lower element to stretch. Charge develops across each layer which counteracts the imposed strains. X: Deflection Limit is proportional to Length² Voc: Open Circuit Voltage proportional to X/L Isc: Short Circuit Current proportional to L x W 6

Piezoelectric Energy Generation Reference: Seminario “RFId: sensors e energy harvesting” – LIUC Universita Carlo Cattaneo – 5 giugno 2009 7

Piezoelectric Energy Generation Courtesy Mide Volture Data Sheet 8

Piezoelectric Energy Generation (Factors: Frequency of Vibration, Amount of Piezo Material, Tip Mass and G-Level) Courtesy Mide Volture Data Sheet 9

Piezoelectric Energy Generation (Factors: Frequency of Vibration, Amount of Piezo Material, Tip Mass and G-Level) Courtesy Mide Volture Data Sheet 10

Piezoelectric Energy Generation Piezo Systems, Inc. A lot of available power Courtesy Piezo Systems Data Sheet 11

Thermal Energy Generation Power generation caused by a thermal gradient between two dissimilar metals. • Peltier Effect: Heating or Cooling at Junction • Seebeck Effect: Energy generation at Junction • Milliwatt Power Levels 12

Thermal Energy Generation - (TEG) Courtesy Linear Technologies Corporation 13

Thermal Energy Generation - (TEG) Voltage is proportional to temperature difference The length and area of each elements sets its basic properties as thermal and electrical resistance The P-N elements are connected in series in a module Series connection gives higher voltage (and resistance) From thermal point of view, they are connected in parallel 14

Thermal Energy Generation - (TEG) System Thermal Model Courtesy Linear Technologies Corporation 15

Thermal Energy Generation - (TEG) System Thermal Model 16

Thermal Energy Generation - (TEG) System Thermal Model TEG Device Heat Flow 17

Thermal Energy Generation - (TEG) 18

Thermal Energy Generation - (TEG) 19

Thermal Energy Generation - (TEG) TEC ≡ TEG an N-P pair is called a “couple” Courtesy Linear Technologies Corporation 20

Thermal Energy Generation - (TEG) High Efficiency 21

Thermal Energy Generation - (TEG) Courtesy Marlow / Evergen 22

Thermal Energy Generation - (TEG) Courtesy Marlow / Evergen 23

Energy Generation Come back tomorrow 24