Researchers at the University of California Los Angeles have partnered with Stanford University on a pioneering new renewable energy technology which generates electricity from the night sky.

It works by channelling the residual warmth from day-time hours into the cooling night air and has been progressed to show that even the cold environment of outer space could become a potential source of renewable energy.

The researchers believe that the discovery could become a potential adjunct to solar energy, allowing the two approaches to be complementary. The power output of night-sky electricity generation would naturally have a lower energy output than daylight solar, but it could be used to continue passively generating power at hours when solar cells were out of play.

This is particularly important for matching energy production to usage, as most people return home and ramp up their energy needs as the sun is setting. Traditionally, fossil fuels have been used to compensate for the energy spike needs. For those without access to the grid, access options for energy are limited.

The test prototype produced by the scientists produced just enough energy to keep a hearing aid powered. The amount was small, but the team behind it are excited by the early results. They have suggested that with the right conditions and optimisation of the approach, it could be possible to generate 500 MW of clean energy at night per square metre of installation.

This could become an enabling technology for clean power generation at remote locations as well as places generally that need power at night. The scientists suggest that the innovation wouldn't need to displace bigger and more established renewable technologies, but it does offer insight into the possibility of smaller and interesting alternatives, particularly for night-time generation.