One of the most unusual looking cars at this year’s Shell Eco-marathon Europe was testing out one of the oldest concepts for harnessing energy for motion: the Stirling heat engine.

Unfortunately, the team’s vehicle did not pass the qualifying tests for the competition that ended Saturday in Rotterdam. The car was too heavy and too high, due to the system coils on its roof. But the vehicle did complete some test runs to try out a concept that the students think has promise for future energy systems.

Michael Dold, who is earning his master’s degree in energy conversion at the school, explains one of the Stirling engine’s great advantages is that it can be used with any fuel source. (Team Schluckspecht powered