Fundamentals of Energy Harvesting and Conversion

Every environment carries energy that nobody switched on: light, heat, vibration, radio waves and a constant stream of particles. Energy harvesting is the engineering discipline that converts some of it into electrical power. It already runs wristwatches, road-side sensors and building controls, and it sets a hard question for every design: how much power is actually there, how much of it a material can take in, and how much survives the conversion.

This section explains the field from the ground up. It covers the established models for single sources such as vibration, temperature differences, light and radio frequency, shows how to calculate what a harvester can deliver, and follows the problem from the material to the device and from one device to many.

Each page starts from a concrete scientific or engineering question, sets out the standard approaches with their strengths and limits, and then shows how a generalized framework treats several weak inputs acting on one material at the same time. Every example uses illustrative values that are marked as such.

Mathematics and Models

• Mathematical Models for Multi-Source Energy Harvesting
  The base equations of energy harvesting side by side, and how several weak inputs in one material can be described together.
• How to Calculate Ambient Energy Harvesting
  A step-by-step method for estimating harvested power, with the standard formulas and a worked power budget.
• Energy Conversion from Environmental Radiation
  The ambient radiation around us as an input space: intensities, the limits set by thermodynamics, and how to add the channels.

Materials and Interfaces

• Graphene in Energy Conversion: From Charge Mobility to Output
  What graphene's mobility, thermal behaviour and fluctuations mean for energy conversion, and where the gap to usable output lies.
• Graphene-Silicon Heterostructures and Charge Separation at Interfaces
  How interfaces turn excited charge into current: p-n and Schottky junctions, rectification limits, and layered stacks.

Devices and Applications

• Powering Autonomous Sensors Without Batteries
  Power budgets, duty cycles and storage for wireless sensors, and when a harvester can cover the load.

Systems and Scale

• Distributed Generation: Mathematical Models for Many Small Sources
  Aggregation, variability and capacity credit for thousands of small generators, and what changes when each source runs continuously.
• Microgrids and Local Energy Balance
  Balancing generation, storage and load at village or campus scale, and how a decentralized energy cell is sized.
• Continuous Power for Data Centres
  The flat, around-the-clock load of data centres, how it is supplied today, and how continuous on-site generation fits it.
• From Microscopic Conversion to Grid Scale
  The path from material layer to module, device and grid: what is gained and lost at each step, and how to calculate it.

Published by the Neutrino Engineering District.