WASHINGTON -- How is this for a road trip? One driver is covering 32 thousand miles, five continents, and 40 countries, all without spending a dollar on gas. His name is Louis Palmer, and his secret is solar power.

Palmer is a teacher from Switzerland who dreamed of traveling around the world when he was 14 years old but never wanted to pollute the environment.

"I had a dream as a boy; I want to drive a car around the world to see the beauty of this world, but I thought how to do that with a petrol engine, a petrol motor--I'll destroy the world," said Palmer. "I thought a solar car would be perfect because that is zero emission."

However as an adult, he wasn't able to buy one commercially so he started working on making one himself. Palmer said he had help from four Swiss universities and 200 people to create what he calls the "solar taxi."

The three-wheeled vehicle can travel up to 55 mph. A trailer with solar panels follows behind it, but Palmer said realistically the panels need to be on buildings to truly provide enough juice to recharge the batteries. Every night Palmer plugs the car into a typical electrical socket to recharge two batteries, and he said the watts he uses while driving in the United States will come from the solar panels on his home in Lucerne.

So far, he's traveled through India, Saudi Arabia, China, Australia, Canada and the United States, and Palmer's journey isn't over yet. His next stop is Philadelphia, and he will eventually head to Africa. Palmer hopes to be back in Switzerland by Christmas.