It started with the mud.

Icky, sludgy, smelly mud from the depths of the Potomac. At age 13, Sikandar Porter-Gill became fascinated with alternative fuel sources and wanted to see whether he could harness the bacteria in mud from the river to generate power.

His "mud battery" was a success. Now, two years later, Sikandar has moved on to bigger things: experimenting with ways to turn sewage into power. Yes, that's right, sewage.

Yesterday, Sikandar, 15, presented the findings of two years of experimentation to officials with the Washington Suburban Sanitary Commission's Seneca wastewater treatment plant in Germantown -- people who are always looking for ways to do smarter things with sewage.

Dressed in dark slacks, a blue shirt and blue-checked tie, Sikandar nervously fired up his PowerPoint presentation.

"My experiment is called 'Improvement of a Single-Chamber Microbial Fuel Cell Utilizing a Novel Concept of a Hydrophobic Coating at the Cathode and the Incorporation of Graphite Granules at the Anode Electrode,' " he said earnestly.

Translation? Sikandar, a sophomore at Gaithersburg High School, has spent the past two years trying to develop a cheaper, more efficient microbial fuel cell. The cell is used by scientists to harness the chemical reaction that occurs when bacteria digest the organic matter in sewage. That process produces small electrical charges, which are captured for power.

"I wanted to find a cost-effective way to produce [microbial fuel cells] and then have them make more power," Sikandar said. The cells and sewage are a perfect combination, because they both are "harnessing a process that's already going on in nature."

As part of that effort, Sikandar, whose parents are molecular biologists, experimented with membranes and coatings that are built into the microbial fuel cell. He thinks his biggest breakthrough this time is using graphite granules, which act as the electrode in the single-chamber microbial fuel cell.

As a freshman, he had built a two-chamber microbial fuel cell but found that he could generate 19 percent more power from the single-chamber setup, despite using less sewage.

"He just keeps progressing," said his mother, Patricia Porter-Gill, who remembers donning rubber boots to dig mud out of the Potomac for the first experiment.

Officials with the sanitary commission were impressed.

"It's a great experiment that has a lot of potential," said Sam Amad, manager of the Germantown treatment center, after watching the teen's 15-minute presentation. "It was a real treat and pleasure to work with Sikandar."

The idea of using sewage to generate electricity has been around since the early 1900s, but the science has only taken off in recent years. The breakthrough came when scientists discovered that it is possible to generate electricity without having to use chemicals in the process.

In researching his project, Sikandar consulted with Bruce Logan, Kappe Professor of Environmental Engineering at Pennsylvania State University, a leader in the field of microbial fuel cell research. Work on microbial fuel cells is also being done at the University of Massachusetts at Amherst.

"Sikandar is one of the first people to find out about this and to strike up a dialogue," said Logan, who published a paper on his own research in 2004.

Logan said that some of his grad students who are doing similar work have said jokingly that they might one day be working for the teenager.

Yesterday, as Sikandar concluded his presentation, members of the audience asked to see models of his work, which he keeps in a shoebox with a green lid.

Employees gathered around him, asking about coatings and the merits of different methods of filling the fuel cell with wastewater.

"At first, I didn't quite understand what he was doing," said Jorge Tello, a senior plant operator. "But it looks very promising. We're very impressed."

The next stop for the young scientist? The regional science fair, where he hopes to make a good showing.