Siksha Sarovar

Siksha Sarovar (sikshasarovar.com) is a free educational web application that helps students in India learn programming and prepare for academic and competitive exams. The platform offers structured coding courses (C, C++, Python, Java, HTML, CSS, PHP, Power BI, AI, Machine Learning, Data Science), complete university curriculum notes for BCA/MCA students with previous year question papers, Class 10 and Class 12 CBSE/HBSE school notes, and dedicated preparation material for SSC, UPSC, Banking, Railway and other government exams. Browsing the site is completely free and requires no account. Users may optionally sign in with Google solely to save their learning progress, quiz scores and personal preferences across devices.

Privacy Policy | Terms of Service | Contact Siksha Sarovar | About Siksha Sarovar

v4.0.9 · PWA
Siksha Sarovar logo
Siksha Sarovar
Your Learning Universe

Siksha Sarovar is a free e-learning platform for coding courses, BCA university notes and competitive exam preparation. Optional Google sign-in saves your learning progress across devices.

Initializing knowledge base…
Compiling modules 0%

2.8 Power Management and Energy Harvesting

Lesson 14 of 31 in the free Internet of Things (IoT) notes on Siksha Sarovar, written by Rohit Jangra.

2.8.1 The Energy Crisis in IoT

Battery replacement is the #1 logistical bottleneck in large-scale IoT. Designs must focus on Deploy and Forget principles.

2.8.2 Sleep Modes Analysis

Modern MCUs (like the ESP32) offer granular power states:

  • Active Mode: CPU and Radio fully on (~100mA).
  • Modem-Sleep: CPU on, Wi-Fi radio off (~20mA).
  • Light-Sleep: CPU suspended, RAM contents preserved (~0.8mA).
  • Deep-Sleep: Only the Real-Time Clock (RTC) is alive. Consumption drops to < 10μA.

2.8.3 Energy Harvesting (EH) Technology Matrix

SourceTechnical TransducerEfficiencyIoT Typical Usage
LightPhotovoltaic (PV) cells15-20%Agricultural sensors
VibrationPiezoelectric elements1-2%Structural health monitoring
ThermalThermoelectric Generator (TEG)5%Industrial boilers, Wearables
RF EnergyRectenna (Rectifying Antenna)< 1%Passive RFID, battery-less remotes

2.8.4 Design Strategies for Longevity

  1. Adaptive Duty Cycling: The node wakes up to transmit only when a significant change occurs (e.g., Temp changes by > 1 degree).
  2. Edge Aggregation: Averaging 100 samples locally and sending 1 mean packet to the cloud.