Researchers have succeeded in manipulating solar panels to generate electricity at night. Although the production is lower, continuous electricity generation will be possible. These panels are of great importance especially for isolated areas where there is no electricity.
Continuous electricity generation
Solar panels are one of the main sources of renewable energy. Their biggest flaw is their inability to generate electricity at night.
Often, this generation is mixed with other sources that compensate for this weakness, but this is not always possible for off-grid installations. Isolated places rely on expensive and limited-life batteries that are then charged during the day.
They added a thermoelectric generator to the standard solar panel
Researchers at Stanford University wanted to solve this problem by creating solar panels that generate electricity at night.
In an article published in the journal Applied Physics Letters, they describe their prototype consisting of a standard solar panel to which they added a thermoelectric generator.
How does the system work?
On a clear night, the solar panel releases its heat directly into space, making it slightly cooler than the surrounding air. The thermoelectric generator uses this temperature difference to generate current.
This technique produces only 50 milliwatts of current per square meter, which may seem like little to you. However, a conventional installation in a 20 m² house will produce one watt of electricity per night.
The researchers think they can double the efficiency with a few changes, and they estimate that the maximum theoretical efficiency could reach one or two watts per square metre.
Their invention will allow isolated installations to operate without batteries and produce enough energy to charge a smartphone or power low consumption LED lighting.