Subtitles section Play video Print subtitles When you think of green energy, solar or wind power springs to mind --but generating electricity from rain drops that fall against a window or roof? That's one method local researchers have come up with, and they say that's just the beginning of the technology's potential. Sohn Jung-in explains. A piece of glass substrate is connected to a small LED light bulb. When droplets of water fall one drop at a time onto the substrate, the bulb gives off a pale light. With the indoor lighting turned off, the flashing light, resembling that of a firefly can be seen more easily. This time, the researchers use a shower faucet to sprinkle water onto the glass substrate. The bulb emits an even brighter light. The secret is in a new advanced energy device that turns moving droplets into electric power. It alters the electrical characteristic of waterdrops, which makes the electrons inside move suddenly, generating electricity. "Water that is normally neutral instantly becomes positively charged due to the device, which causes electrons to move." One single drop of water can create up to 0-point-42 milliwatts, which can light three to four LED bulbs at a same time. Researchers say the technology can be applicable to our daily lives. Using water that is wasted in kitchen or bathroom sinks could bring about a new assessment of the true value of water, literally making every drop count. Sohn Jung-in, Arirang News.