Solar Power: Photovoltaic, Electrochemical, Hydrogen

In two hours, the energy of the sun's light that reaches the Earth's land surfaces equals what the world's current population consumes in an entire year.
Purdue Engineering's solar research focuses on solar–cell, or photovoltaic, technology that converts sunlight directly into electricity.

Solar cells, whether arranged singly or in modules or arrays, can provide tiny amounts of power for watches, large amounts for the electric grid, and everything in between.

Inefficiency: Our Opportunity for Progress

Current technology provides about 18 percent cell efficiency in laboratory environments.

"This efficiency drops to 10 percent when the solar cells move into public usage, and a challenge in this research is to find out why this happens and to increase the efficiency of solar cells in different environments," says Rakesh Agrawal, Purdue's Winthrop E. Stone Distinguished Professor of Chemical Engineering. "Another challenge is to reduce the size and cost of solar cells."

At the Energy Center, Purdue researchers will continue solar–cell research and also explore advanced electrochemical methods and hydrogen energy systems that change the way we generate, store, and use energy (see "Mike Ramage and the Road to the Hydrogen Economy").

On the agenda: solar hydrogen, electrosynthesized materials, photo–bio–electro–chemical hydrogen generations, fermentation of biomass–based hydrogen production, and biofuel cells. The College of Engineering's Purdue Hydrogen Economy initiative, for example, is taking up President Bush's 2003 call to achieve sustainable development through this most plentiful of elements. In August, Purdue researchers under the direction of chemical engineering head Arvind Varma, the R. Games Slayter Distinguished Professor of Chemical Engineering, announced a new way to produce hydrogen for fuel cells that will extend the charge of wireless electronics—no wall outlet required. The work received a "Technology of the Year" award from Industry Week magazine.

—Lisa Hunt Tally with Cynthia Sequin