
Solar energy has always relied on sunlight, but a new technology is changing the game. Scientists at Stanford University have developed solar panels that can generate electricity at night.
This technology uses a natural process called radiative cooling, which occurs when heat escapes from the Earth's surface into space on clear nights.
How do these solar panel works?
The secret lies in thermoelectric generators attached to standard solar panels. These devices capture the heat difference between the panels and the cooler night air, producing small amounts of electricity, around 50 milliwatts per square metre.
This is far less than the 200 watts per square metre generated during the day, it is enough to power devices like LEDs and environmental sensors.
Over 770 million people live without reliable power, and this technology offers an affordable way to light homes and run basic devices. It can also be added to existing solar systems, reducing dependence on expensive, polluting batteries.
The potential of these nighttime panels goes beyond electricity. Radiative cooling is already used in cooling systems and water generation in dry areas.
By improving this technology, researchers believe they can make solar energy more reliable, even in regions with frequent cloud cover or less sunlight.
Challenges remain, including the cost and the need for better materials. However, with further research, these panels might become a sustainable solution for off-grid communities and contribute to a cleaner future.