Fossil fuels—including coal, natural gas, and oil—are formed from the fossilized remains of prehistoric plants and animals, and fossil fuels provide about 95% of the world's total energy. Alternative fuels are better for the environment and often better for the economy than fossil fuels.
One of the most promising alternatives to fossil fuels is solar energy. While the basic technology has been in place for decades, the expense of generating and storing solar energy was often cost-prohibitive. That is changing as ways to mass-produce effective solar energy systems for residential and commercial spaces have come into being. Today, some consumers are building homes that at least partially use solar energy for heating and cooling, rather than employing more traditional methods that make use of petroleum based products.