Lemon Power

Cars are a fast and convenient way to travel. However, most cars on the road move by burning gasoline. The gasoline emits, or gives off, pollution into our air. While there are some electric cars, most electricity is produced by burning coal, oil, or gas, which creates even more air pollution! But what if we could find a more eco-friendly solution for powering our cars? The car company Volkswagon challenged science YouTuber Mark Rober to power a battery for an electric supercar that would race up a hill for 12.5 miles. That's about the distance of 200 soccer fields! Mark's plan? Build the world's largest lemon battery.

A lemon can produce electricity when it reacts with two different metals: zinc and copper. The metals are then connected by a wire and electrons are pushed through, creating an electric current. Mark gathered 1,232 lemons for his giant battery! He used "class two" lemons, which stores can't sell because they're overripe, oddly shaped, or too small. However, when Mark tested his lemon power it only created enough energy to power a single AA battery. He realized using the lemons in this way would never power the car enough.

Mark brainstormed a new solution: a zip line that would charge the battery every time it slid down a rope. He invited a group of kids to use his zip line, and repurposed the lemons for lemonade. The lemonade helped give the kids the energy to use the zip line over and over! This solution was fun and inventive, but it still didn't generate enough power. Finally, Mark installed 24 solar panels on the roof of his garage, and  asked some young inventors to create a sprinkler system to keep the panels clean. With the final power generated from the solar panels, Mark was able to fully charge the car for the race using all eco-friendly power sources!

What could you invent to power an electric car? Show us your ideas in the design section!