Wireless Sensor Networks (WSN) are expected as the key to realize Ubiquitous Sensor Networks (USN). Some examples of potential early adopters of WSN applications include smart buildings, environmental monitoring, and physical security. However, a key issue for the wireless sensor is the power supply. Currently wireless sensors are powered by small batteries that under proper management can provide power up to five years. However, such systems are inefficient and relatively expensive in the concept of ubiquitous sensor networks. Energy Harvesting draws attention as an alternative to solve the power supply problem. Energy harvesting is the technology to generate energy from the environment and promises to enable inexpensive wireless sensors. OMRON Corporation of Japan is a world leader in Micro Electro Mechanical Systems (MEMS) based sensors and has a keen interest in energy harvesting technologies. The author is a member of OMRON’s R&D Center and is researching energy harvesting technologies. He will present an overview of the current state-of-the-art of such technologies and applications. He will also present his thoughts on potential successful business models for energy harvesting technologies.