CHARLESTON — The United States’ electrical infrastructure is about 100 years old and ruled by alternating current, or AC. But, the modern world around us — household appliances, laptop computers, cell phones and devices — is powered by direct current, or DC.

A conference this week in downtown Charleston is showing how the world is witnessing a transformation in electricity generation, delivery and technology.

“DC electricity is a game-changer for the 21st century,” said Rajendra Singh, a Clemson University professor in the Holcombe Department of Electrical and Computer Engineering, and conference organizer.

In alternating current, the flow of electric charge periodically reverses direction. In direct current, the flow of electric charge is only in one direction.

The U.S. electricity infrastructure of generation, transmission and distribution was built over the course of a century. This aging infrastructure is experiencing dramatic change, all of which could threaten the stability, reliability, resilience, affordability and environmental impact of this vital source of energy.

The two-day conference, hosted by Clemson University and the Clemson University Restoration Institute, addresses the emerging directions in the generation, distribution and utilization of electricity.

Experts from industry, federal laboratories and academia discuss the latest developments in this emerging segment of energy industry.

In his keynote address, Jim Rogers, retired chairman and chief executive officer for Duke Energy, told the conference that direct electrical distribution is “on the march.”

Roof-top solar power is just one example, he said. And, development of electric-powered vehicles and the necessity for more efficient and longer-lasting batteries is leading to advances in electrical storage technologies.

“We’re beginning to see a lot of movement in this direction,” Rogers said.

Other conference speakers include Don Talka, senior vice president and chief engineer for Underwriters Laboratories; Lewis Gossett, president and chief executive officer for the S.C. Manufacturers Alliance; and Nick Rigas, executive director of the Clemson University Restoration Institute. Rigas and Curtiss Fox, director of the Duke Energy eGRID at the Restoration Institute, explained how the advanced grid simulator can help advance DC technology.

The conference is sponsored by the S.C. Research Authority (SCRA), EMerge Alliance, Duke Energy, StarLine DC Solutions, Argonne National Laboratory, Emerson Electric Co., and The InterTech Group.

According to the U.S. Energy Information Administration, about 70 percent of electrical energy is lost in the generation, transmission and distribution. DC electricity, locally generated by solar panels, wind farms or other sources, is expected to save 30 percent of this loss.

DC-powered devices offer reduced energy loss, improved power quality and greater lighting efficiency. Challenges include size, cost and system integration.

Bill Mahoney, chief executive officer for SCRA, a research and development and technology incubator, said the most promising applications for DC electricity include industrial motors, consumer electronics, LED lighting, and electric vehicles. Many of these are multi-billion dollar industries, he said.

“There are lots of obstacles to overcome, but primarily there are opportunities,” Mahoney said.

The conference concludes today.