How to present a race for the lowest score

We have an energy dashboard in a STEM elementary school. One of the pages is a competition for the most efficient building which starts at 8:00 AM Monday and completes 2:45 Friday.

We are currently showing a race where the distance run by each building is calculated as described below. This allows all teams to start at a starting line at the beginning of the week/race, for the most efficient building to reach the finish line at the scheduled competition ending time, and for each building to be positioned based on its current efficiency.

(TimeElapsed/CompetitionDuration) * MIN( EnergyUse(i)/SqFt(i) ) * ( SqFt(i)/EnergyUse(i) )

This approach, however, is not very intuitive since the winner is the team with the lowest score (energy use per square foot). Additional, a typical race has a set distance to travel but not a set time to complete, which makes it even less intuitive. We also considered dictating each team's score based on their energy use against a baseline energy use, however, this can result in a team going backwards which might be difficult to understand.

How should a competition be presented where the winner is the team who uses the least energy?