are total efficiency, power and time for landing respectively.
4.0 Economical Alternative to PV
The solar energy reaching the Earth (visible and MID-IR regions) and that reradiated (MID-IR energy) from Earth are under-utilized by photovoltaic technology. An economical alternative to the quantum devices is nanoantenna based on natural resonance. If an antenna could detect longwave radiation, it could also convert it into electricity. Assuming the antenna is not in thermal equilibrium with its surroundings it is possible to scavenge energy from the environment without violating the second law of thermodynamics. Rectennas (Nano antennas coupled to a tunneling diode) that use excited localized surface plasmons tuned to the Mid-IR can harvest IR energy from the sun at night and day and convert it into DC electricity all day.
4.1 Antenna and Theory of Operation
Compared with conventional solar cells based on quantum mechanics rectennas based on Maxwell’s equation seem be a technology that can be efficient, requiring only low-cost materials. A rectenna circuit consists of an antenna connected to a diode, as shown in Figure 7.