The concept you're describing is known as wireless power transfer (WPT), where electricity is transmitted wirelessly from a source to a receiver. One method of WPT is using microwave power transmission, which involves beaming microwaves from a satellite or other space-based system to a ground station. However, redirecting the power directly to individual devices or appliances using rectennas built into them can present several challenges:
Efficiency: Wireless power transfer over long distances can suffer from significant power loss during transmission. Even with advancements in technology, there are still efficiency limitations when it comes to converting transmitted energy into usable electricity. This can result in inefficient power transfer and potential energy wastage.
Directionality and line of sight: Efficient wireless power transfer typically requires a clear line of sight between the transmitter and receiver. If the receiver is built into an appliance or device, it may be difficult to maintain a direct and unobstructed path for power transfer. This can impact the reliability and effectiveness of the wireless power transmission.
Standardization and compatibility: For wireless power transfer to be widely adopted, standardization of the technology and compatibility between devices and receivers are crucial. Implementing rectennas into various appliances and devices would require a unified standard to ensure seamless integration and interoperability. Achieving such standardization across a wide range of devices can be challenging.
Safety concerns: Wireless power transfer technologies need to adhere to strict safety standards to ensure that they do not pose health risks to humans or interfere with other electronic devices. Integrating rectennas directly into appliances and devices would require careful consideration of safety measures to mitigate any potential risks associated with the wireless power transfer.
While the concept of integrating rectennas into devices to reduce the need for a centralized ground station is intriguing, there are several technical and practical challenges that need to be addressed. Ongoing research and development in the field of wireless power transfer are focused on improving efficiency, standardization, and safety, but widespread implementation of such technology for individual devices and appliances is not yet a practical reality.