Rain can be a clean way of generating lots of electricity

Water drops that fall through a tube have generated enough electricity for power 12 LED lights. Such an approach could one day be used in roof -based system to harvest lots of pure power from rain.

“Rain falls on the ground every day. All energy is wasted due to the lack of a system to harvest rain energy,” says Siowling Soh at the National University of Singapore.

Usually, when we generate electricity from water, we use the movement of plenty of it to drive a turbine in the river, sea or even in drinking water pipes. But water flowing over an electrically conductive surface can generate its own electrical load through a process called load separation. This is driven by positive charging protons of the water molecules that stay in the liquid and negatively charged electrons donated to the surface, as well as to generate static electricity by rubbing a balloon on your hair.

The phenomenon is usually an ineffective way of generating electricity because the electric only creates on the water that the water touches, and if you use micro or nanoscala channels to include surface area, you end up requiring more energy to pump the water you come out again.

Now, Soh and his colleagues have created a simple setup that binds on gravity to move water down a vertical tube 32 centimeters high with an inner diameter of 2 millimeters.

Water flows out of the bottom of a container via a horizontal, stainless steel needle and then falls against the tube below. When the rain -like water drops collide at the top of the tube, they catch pockets of air and create what is called a sacker current as they fall. This disjoinated flow seems to help the electrical charges of the water molecules to separate asy trips down the tube. Wires at the top and bottom of the tube then reap the generated electricity.

In an experiment, a pipe produced 440 microwaves. When the researchers used four pipes at once, they could operate 12 joints for 20 seconds.

“We can for the first time harvest the rainfall of the rain or other natural sources such as rivers or waterfalls via charging separation at the fixed fluid interface,” says Soh.

The amount of generated electricity may not seem very impressive, but Soh says the setup converted more than the energy in the water that falls through the pipes to electricity, which is five orders of magnitude more electricity than obaworked from pipes in a continuous current.

“Rain falls from a seed milometer up into the sky to the ground, so there is a lot of space in three -dimensional space to harvest rain energy,” he says. This suggests that the system could be used to generate electricity from rain, perhaps on the rooftops.

“If it could be developed in a way that could be useful on a househouse basis, it can be a really useful mind,” says Shannon Ames at the Low Impact Hydropower Institute in Boston.