Some types of bioenergy are more efficient than others in becoming a usable form of bioenergy. For example, wood and corn are very intensive, meaning that they have a lot of potential energy per unit of weight. However, even biomass that is not as intensive can also be very useful. For example, manure is a form of biomass that is readily and abundantly available due to livestock production, but hardly any production facilities use it for anything else than fertilization of land.

At the same time, conversion of waste into usable energy is an area that has a lot of potential from a bioenergy standpoint because the environmental impacts of it can be very large. Waste can include not only animal manure, but also all kinds of waste generated by people, including garbage and commercial waste.

The downside to the conversion of waste into bioenergy is that most waste products are not easily combustible. Those that are combustible, can create a wide range of pollutants, some of which are even worse than the ones created by fossil fuels.

On the other hand, agricultural waste can be a source of tremendous amounts of energy and there will be no damage to the environment in the process of creation of this type of bioenergy. Rice, sugar cane and corn are the plants that look very promising from this perspective. The byproducts of these foods, such as husks, are easy to harvest, and harvesting them does not require a lot of time or money. Traditionally, farmers were sending these products to landfills, but with technological advancements, there are opportunities to convert these by-products into biomass and bioenergy.

In addition to using byproducts of plants, it is possible to create bioenergy from growing plants for this purpose. Typically, such plants would be starchy plants such as corn or wheat and cellulose-based plants such as trees and grass.