CLEMSON’S EFFORT TO BRING ELECTRICITY to the globe’s darkened corners has gathered momentum since the White House honored a professor for his four decades of work with solar energy.
Rajendra Singh said that his work has accelerated since the White House named him one of 10 “Champions of Change” for solar deployment this spring. Groups that support green technology and other aspects of his research have been approaching him in the wake of last month’s award, he said. Singh is the D. Houser Banks Professor of electrical and computer engineering and director of the Center for Silicon Nanoelectronics.“Can we do something that I never thought would happen in my lifetime? Well, now it’s close to reality,” said Singh.
Singh said the technology is available to bring electricity to the entire world in as little as five years while lowering utility bills in the United States. It’s a matter of integrating electrical components, finding a business model that works and moving public policy in the right direction, he said.
According to Singh, about 1.5 billion people have no access to electricity and another 1 billion have access only to unreliable electricity networks. And providing basic education, health care and life skills are all dependent on electricity.
Singh’s focus is on solar power because fuel from the sun is free. At the same time, hardware prices for solar power are falling faster than for wind power. Solar panel costs fell by 62 percent from 2011 to 2013, while wind turbine costs dropped 12 percent, Singh said.
Part of the challenge in bringing electricity to some areas is figuring out how to deliver it to rural towns and villages that are disconnected from main grids. For Singh, the solution is to create microgrids and nanogrids that get their power from solar panels and distribute it like mini-utilities. Microgrids cover a small area, such as a single town, while nanogrids are small microgrids that distribute power to an even more limited area, such as a village of a few dozen homes. Batteries are used to store the electricity.
Singh is an advocate of using direct current (DC) in microgrids and nanogrids, a concept he said is similar to what Thomas Edison had in mind when he invented DC transmission. Solar panels generate DC electricity. The sprawling grids that deliver electricity to most homes and businesses around the world carry alternating current (AC), Singh said. While the cost of generating local DC power has fallen, AC power generated by centralized facilities has remained the same, Singh said.
“Wind- and solar-generated power is cheaper than power produced by coal-fired plants when factoring the social costs of carbon,” he said. Using direct current also solves an electricity-conversion problem. LED lights and an increasing number of consumer devices, such as televisions, run on DC electricity, Singh said. So do battery-based hybrid and electric cars.
When AC electricity flows into homes and businesses, it has to be converted to direct current to power DC devices. More than a third of the energy can be lost in conversion, Singh said.
“Globally, as the AC electricity infrastructure retires, all new electricity infrastructure should be built on DC,” Singh said. “Loads that require AC must be equipped to convert AC into DC. The dominant use of DC in place of AC will be a major improvement in increasing our energy efficiency.”
If Singh’s ideas sound futuristic, it wouldn’t be the first time he was a step ahead of the pack. Work he did in “rapid thermal processing” in the 1970s and 1980s helped lay the foundation for solar-cell and semiconductor manufacturing. He is now leveraging his experience to overcome the technical and business challenges that come with bringing electricity to the parts of the world that remain in the dark.