solar cell

Reverse Solar Panels – Generating Electricity From Shadow

A gadget, dubbed as “shadow-effect energy generator,” is a solar cell-like material that generates an electrical current when part of it is in the light and the other part isn’t. Its like shadows and light teaming up to provide power.

The scientist from The National University of Singapore created the ‘shadow-effect energy generator’ by placing a superthin coating of gold on silicon, a typical solar cell material.

Like in a solar cell, light shining on silicon energizes its electrons. With the gold layer, the shadow-effect energy generator produces an electric current when part of the device lies in shadow.

The excited electrons jump from the silicon to the gold. With part of the device shaded, the voltage of the illuminated metal increases relative to the dark area and electrons in the generator flow from high to low voltage. Sending them through an external circuit creates a current that can power a gadget.

The greater the contrast between light and dark, the more energy the generator provides. So the team is working to boost the device’s performance by borrowing strategies from solar cells for gathering light.

Increasing the light these generators absorb would allow them to better exploit shadows.

With eight generators, the team ran an electronic watch in low light. The devices can also serve as sensors. When a remote-controlled car passed by, its shadow fell on a generator, creating the electricity to light up an LED.

The cost of all components to make the SEG device is around $30 to $50 which is low compared to the hundreds of dollars that are spent to make commercial solar panels per square meter.

While the electric current from the proof-of-concept generators is weak for now, it hints at a future in which clean energy generation becomes far more ubiquitous and commonplace.

Reference- Science News, Energy & Environmental Science, Futurism, Tech Times