A solar-powered microwave transmission system is proposed for remote sensing and communications purposes. We present in this paper a proof of concept to operate solar-powered microwave transmission and an investigation of microwave interactions with atmospheric plasmas. In this conceptualized system, a solar thermophotovoltaic system is considered to produce direct current electricity, which is then used to power solid-state microwave transmitters. The results from these simulations provide insights on how to produce an economically and environmentally conscientious energy source, which can be used for remote-sensing and communication applications. However, it is expected that microwaves may interact with ionospheric plasmas, primarily in the E-region to induce large-scale fluctuations in plasma density and geomagnetic fields with threshold wave electric-field intensities of ~ 1 V/m. After we determine the instability thresholds, we can use them to set up the safe operation range of solar-powered microwave transmission.