# Introduction to Energy Harvesting Energy Harvesting (EH) is the process of capturing and storing small amounts of energy that would otherwise be lost as heat, light, sound, vibration, or motion. EH technologies provide a very small amount of power for low-energy electronics. ## Energy Harvesting Sources These are the main sources of energy harvested: - **Solar Power:** Photovoltaic cells convert sunlight directly into electricity. - **Thermal Energy:** Thermoelectric generators convert heat differentials into electricity. - **Wind Energy:** Miniature wind turbines can generate power for remote sensors. - **Kinetic Energy:** Vibrations or human motion can be converted into electricity using piezoelectric materials. ## Energy Harvesting Systems An energy harvesting system typically consists of an energy source, a transducer, power management circuitry, and an energy storage device. The transducer converts the harvested energy into electrical energy, which is then conditioned to power the electronic system or stored for later use. ## Application in IoT Devices Energy harvesting is particularly useful for IoT devices that are impractical to service frequently or are inaccessible. For example, a sensor in a remote location can harvest energy from its environment, eliminating the need for battery replacement. Here's a simple example of how software can interact with an energy harvesting system using a power management IC: ```python import power_management # Create an instance of PowerManagement pm = power_management.PowerManagement() # Set power source to energy harvester pm.set_power_source(pm.POWER_SOURCE_HARVESTER) # Check if enough power is available if pm.check_power_status() == pm.POWER_STATUS_OK: # Perform tasks... pass else: # Switch to an alternative power source or go to sleep pm.set_power_source(pm.POWER_SOURCE_BATTERY) ``` In this example, the software first sets the power source to the energy harvester. It then checks if enough power is available. If not, it switches to an alternative power source or puts the system to sleep. This helps to maximize the usage of harvested energy and extend the lifetime of the system. With the advent of low-power electronics and the increasing need for wireless, self-powered systems, energy harvesting techniques are becoming more important in the design of autonomous systems. These techniques open up new possibilities and present exciting challenges in the field of software engineering.