EPHRATA — Fifth-grade students at Parkway Elementary learned about energy from the sun as they raced solar cars they built.

The races Thursday were part of a hands-on learning program organized by Grant County Public Utility District. REC Silicon, in Moses Lake, donated the kits for the cars.

Sharon Palmerton, marketing specialist for REC, said the program provides students a basic understanding of how solar cells work. It also stirs imaginations about the greater potential of the sun, she added.

REC participated in the program last fall at schools in Moses Lake and is joining with the PUD again this spring.

About 170 students made cars and raced them at Parkway Elementary. Students at St. Rose of Lima Catholic School will participate next week.

"Our employee volunteers really enjoy the kids' interest and enthusiasm," Palmerton said. "To us it's a clear indication of the program's impact."

The cars, which look like small solar panels on wheels, raced two at a time down a 24-foot long track with barrier walls to keep them from crashing into each other.

While the cars raced down the track, 50-cent words like "photovoltaic" flew around.

Some students experimented with the angle at which the solar panels were positioned on their cars. They knew sunlight directly hitting the solar panels makes the cars go faster.

Teacher Joelle Malone's class spent a couple hours during the previous couple of days building the cars.

Students were excited to put the paper and pencils away and dive into a hands-on project, Malone said. They learned to work independently and problem solve.

The program helps introduce them to the subject of energy, she said.

Once the races end, the students take a quiz.

They must be able to answer questions about how the cars work, how to make them go faster and how to fix common problems, Malone said.

The students learn about tiny packets in sunlight, called photons, which strike the pure silicon of the solar panels, said Jim Frank, PUD energy services specialist.

When photons strike the blue silicon in the panels, it knocks electrons loose. Those electrons spin the tiny motors, sending the rear tires into motion and the cars forward, Frank said.

"There's no waste and no fuel consumption," he said.

The student, at each school, with the fastest car wins a hydrogen-fueled car, Frank said. The car comes with a hydrogen generator for fuel.

Frank said fifth graders are the best age for racing solar cars.

"They're old enough to be excited about it," he said. "But not too old and have preconceived notions about it."