"Sadly it's very hard to generate much energy from small differences in temperature." Nighttime electric power generation at a density of 50 mW/m2 via radiativ

"Sadly it's very hard to generate much energy from small differences in temperature." Nighttime electric power generation at a density of 50 mW/m2 via radiative cooling of a photovoltaic cell https://aip.scitation.org/doi/full/10.1063/5.0085205 https://aip.scitation.org/doi/full/10.1063/5.0085205 Sure, but it does provide some interesting opportunities for embedded technology (LEDs, security cameras, Bluetooth, etc.).