1. Alcohols

Like ethanol, methanol, propanol and butanol, alcohols are naturally produced.

- Methanol can be made from natural gas and biomass (although its not economically viable right now). It is an alternative to the hydrogen economy.

- An other fuel source for motor vehicles used in Brazil is ethanol which is extracted from sugar cane. It is also used in the U.S. as an additive to fuel, but that enthanol is made mostly from corn.. However, a tremendous amount of fuel is needed to produce just a gallon of corn-based ethanol, making it very energy inefficient.

Ex: cornstalks, poplar trees and switchgrass. Byproducts and wastes of forest industry can also be made into ethanol.

- Butal is created through fermentation. Butanol maybe serve as a better fuel source than ethanol since it produces a lot of energy, is less corrosive, and more soluble in water.

2. Gases

-The method of anaerobic digestion is organic material turned into mainly biogas. It can be produced from waste materials of plants and organic material put into anaerobic digesters to increase gas yields. Digestate is one of the by-products of anaerobic digestion and can be used as compost.

- Industrial digesters and mechanical treatment systems can extract gas from the biodegradeable material and collect the gas. Gas escapes from landfill products, producing a less environmentally-friendly form of biogas. This is natural process of anaerobic digestion and given the technology, it can be trapped for more productive uses.

3. Solids

Solids like wood, charcoal, and dried excrement have been used for a long time. Other soild biofuels include starch crops (corn wheat and barley), sugar crops (cane and beet), forage crops (grasses, alfalfa, and clover), oilseed crops (soybeans, sunflower), algae, waterweed, water hyacinth, reed and rushes. Municipal solid waste (paper, food and yard wastes, plastics, wood and tires), livestock waste, process waste, sewage can also be processed and used again as a renewable source of energy.