Yes, it is possible to wirelessly transmit power over a 30km range using microwaves. This concept is known as microwave power transmission or wireless power transfer (WPT). WPT involves the transmission of electrical energy from a power source to a receiver without the need for physical wired connections.
Microwave power transmission works by converting electrical energy into microwave energy, which is then transmitted through the air to a receiving device equipped with a compatible receiver. The receiver converts the received microwave energy back into electrical energy, which can be used to power electronic devices or charge batteries.
There are different methods for implementing microwave power transmission, but one commonly used approach is through the use of a technology called "rectenna." A rectenna is a combination of a microwave antenna (rectifying antenna) and a rectifier. The microwave antenna captures the transmitted microwaves, and the rectifier converts the microwave energy into usable DC electrical power.
For long-range power transmission, several factors need to be considered, including the transmission efficiency, the frequency of the microwaves, the atmospheric conditions, and safety concerns related to human exposure to microwave radiation. High-frequency microwaves, such as those in the millimeter-wave range, are typically used for long-range power transmission as they experience lower atmospheric attenuation.
While long-range wireless power transmission using microwaves is technically feasible, there are several challenges and limitations to consider. These include energy losses during transmission, the need for precise alignment between the transmitter and receiver, potential interference with other microwave devices, and safety considerations.
It's worth noting that the practical implementation of long-range wireless power transmission using microwaves on a large scale is still in the experimental and research phase. However, there have been successful demonstrations of wireless power transfer over shorter distances using microwaves. Ongoing advancements in technology and further research may lead to more efficient and practical solutions for long-range wireless power transmission in the future.