New research in the field of renewable energy has been noted down. 1st time in history scientists has created a device called Shadow-Effect Energy Generator (SEG) that generates electricity from shadows.
Till now the shadows are a major problem for renewable energy, especially for a solar panel. We all know the efficiency of solar panels decreases in cloudy days or if it is not getting direct sunlight. But now the curse has changed into a boon.
The efficiency of this newly developed device increases in cloudy days. The efficiency is maximum when half of the device is exposed in sunlight and half is in shadow.
The SEG uses the contrast between darkness and light to produce electricity. It’s made up of a series of thin strips of gold film on a silicon wafer, placed on top of a flexible plastic base.
The technology is cheaper to produce than a typical solar cell, according to its developers. It produces small amounts of power and could be used in mobile gadgets.
“Shadows are omnipresent, and we often take them for granted,” says materials scientist Tan Swee Ching, from the National University of Singapore (NUS). “In conventional photovoltaic or optoelectronic applications where a steady source of light is used to power devices, the presence of shadows is undesirable, since it degrades the performance of devices.
They mentioned the concept of contrast in illumination i.e. a voltage difference between the shadow and illuminated sections, resulting in an electric current. This novel concept of harvesting energy in the presence of shadows is unprecedented.”
According to the research findings, published in the paper Energy harvesting from shadow-effect, the new device can perform 200% better than commercial silicon solar cells under the effects of shadows.
With passing shadows – caused by clouds or waving tree branches perhaps, or simply the movement of the Sun – the device is able to generate enough power (1.2 V) to run a digital watch, the team demonstrated. That could well be boosted in the future, too.
The SEG also doubles up as a sensor: it can log shadows passing over it to record the movement of objects passing by. That could have various applications in connected smart home devices, for example, and could even be used to create self-powered sensors.
There’s plenty of work still to do, though – the researchers now want to try and bring down the cost of their SEG, perhaps by replacing the gold film with a different material. It could also be adapted for wearable use further down the line.
In the future, the more ways we have of producing renewable electricity, the more imaginative we can get with our gadgets, and the less we need to rely on fossil fuel for energy production. Shadows can now be added to the list of alternative energy sources, alongside snowfall and the cold of outer space.
“With its cost-efficiency, simplicity and stability, our SEG offers a promising architecture to generate green energy from ambient conditions to power electronics, and as a part of a smart sensor systems, especially in buildings,” write the researchers in their published paper.