An important factor in future energy needs will be the combing of energy sources; a primary example is the hybrid automobile. Oil has been a source of energy since the mid-nineteenth century mainly for providing light. With the advent of the electrical bulb, oil demand waned until fossil fuels replaced coal for engines. By the mid-twentieth century, oil became a powerful source of energy.

A replacement for oil would need three things: the creation of minimal pollution, portability and power. If a car does not have enough power to provide all the luxuries that people are accustomed to and can not cruise at a reasonable speed, then no one will buy it. Mopeds already are efficient, but you do not see a family of 4 riding one from the grocery store in Arizona during the summer. A businessman in a suit is not going to ride a moped in 105 degree, humid weather. Hybrids (or even tri-powered) offer the solution. The hybrid does not have to be electric and oil; a combination of solar, wind, biodiesel or clean coal could also be combined. Initially we will most likely reduce our oil consumption by combining it with other sources. Imagine a hybrid car with extra batteries for increased power along with solar panels to squeeze out a little more efficiency.