The potential of biomass as an energy source is enormous: experts have calculated that the planet produces eight times more biomass each year than its energy needs overall (though it currently puts only 7 percent of that available resource to use in energy production). It’s not only a renewable resource, it’s also a seemingly inevitable one; to paraphrase a common aphorism, biomass happens.

Any fuel created from biomass can be called biofuel, although the term gets the most media attention when used to denote biomass-based fuels that power internal combustion engines especially cars. These include biodiesel, biobutanol, biogas and bioethanol. The fuels can be created from plant materials specifically grown for the purpose or from the recycling or re-use of other biomass resources.

Energy Crops
Crops have long been grown to feed people and animals, but until recently were not raised specifically as energy sources. Even trees, which have been used for thousands of years as a heating source, were not “farmed” for just that purpose. Today there is even a term for trees and woody plants cultivated for the specific purpose of creating fuel: dendro-energy. The products of any agriculture dedicated to producing fuel of any sort are called “energy crops” the high-falutin technical term would be “closed-loop biomass” and are steadily becoming an important resource in global energy development.

There are literally hundreds of different dendro-energy resources alone, from abies balsamea (balsam fir) to Zizania aquatica (wild rice) around the world. In countries with no proven reserves of fossil fuels, investments and research in dendro-energy resources have helped otherwise energy-poor nations such as Sri Lanka develop alternatives to costly and politically dependent imports, giving a whole new meaning to the phrase “power plant.”

Some of the energy crops grown around the world include corn, soybeans, flaxseed and sugar cane. Additionally, biofuels are also manufactured frequently from the unused portions of crops grown for other purposes such as the chaff, stalks, shells, husks, and roots.

Energy crops add fewer emissions to the air and water supply than do petroleum products in general and coal in particular. Energy crops contain almost no sulfur and far less nitrogen than fossil fuels, so their combustion does not contribute to acid rain and smog (sulfur dioxide, or SO2) and smog (nitrogen oxides, or NOx). And unlike fossil fuels, they do not have significant quantities of mercury to leach into the water supply. In general, energy crops do not release nearly the amount of volatile organic compounds (VOCs) as anthropogenic sources (that is, human-made concoctions such as natural gas, gasoline, solvents, pesticides, and paints).

There are biogenic sources of VOCs, however, and these do represent significant contributors. Pine and citrus trees, for example, release large quantities of isoprene (a chemical compound found naturally in plants and animals, including humans, isoprene is nevertheless a pollutant, especially as it contributes to the production of ozone) and terpenes (a family of hydrocarbons that are the major components of resin and, not surprisingly, turpentine), although these trees are used as biomass.

One promising source of biofuels is microalgae, which can be grown on aquaculture farms. A pilot program demonstrated in during the 1990s showed that algae can be used to create diesel and jet fuel. This is particularly good news given the efficiency of algae relative to some other energy crops. For example, corn, which is a common energy crop, yields just 18 gallons of fuel per acre. Thanks to its fast growth cycle, algae can yield up to 10,000 gallons per acre. There’s another benefit to algae, too. Some power plants are already using algae bioreactors to reduce CO2 emissions by pumping the gas into a pond or tank for the algae to feed on.

Recycled Energy
Another way in which biomass gets put to use as an energy source is through recycling biodegradable materials or water products. Industry and agriculture are major sources of biodegradable by-products, but every household generates potentially useful biomass. On a large scale, manufacturers and other industrial and commercial services generate biodegradable materials they no longer need.