Highway sound barriers, which are built to reduce noise coming from traffic, are evolving.
They now double as solar panels and produce green energy.
Park Se-young has more.
This sound barrier is different from the ordinary concrete or steel walls.
The four-meter wall is composed of panels with three different functions.
The panel at the bottom is covered with sound-absorbing materials, the clear panel in the middle is soundproof, and the top panel is formed of 240-watt solar panels that can produce energy from both sides.
The electricity from these panels is used by a nearby recycling center.

"We achieved electricity savings of 45-thousand kilowatt hours a year. Our annual electricity bill of around 72-thousand U.S. dollars was reduced by about 45-hundred dollars, …6 percent of the total cost. The walls were also found to cut carbon emissions by around 26 tons a year."

New technology is being developed to make use of the sound barriers' large surface area.
The number of combined patent applications for sound barriers has fallen over the last five years, …but the number of applications for multifunctional sound barriers like those with solar panels or tunnel-type noise barriers has leapt up to make up 30 percent of total applications.

Seoul city is set to complete a soundproof tunnel with solar panels along the Dongbu Expressway by the end of the year.
Both reducing noise pollution and generating power, the tunnel will be the first of its kind in the world.
It will cover an area the size of a football field and generate nearly 830-thousand kilowatt-hours of electricity per year.
The metropolitan government plans to increase solar energy generating facilities like this in an effort to improve the urban environment.
Park Se-young, Arirang News.