As the world's supplies of fossil fuels are used up, the search for new, renewable energy sources is ongoing. At the present time, the energy source that shows the most promise is the use of biomass and biofuels. But, how do these compare to fossil fuels in terms of costs?
In most cases, biomass feedstocks, harvested or collected wood and plant matter, grains, grasses, etc. Must have energy applied to them to break them down into useful fuels that can be used to create energy. In some cases, all that is needed is pressure, such as compressing wood into pellets that can be burned in place of coal to power an electrical generator. Other times, heat must be applied to aid in the fermentation process to produce alcohols that can be burned as fuel. In still other cases, energy is used to reduce biomass to a gaseous form of methane, a fuel similar to natural gas.
On a small scale, the costs of rendering the biomass into usable fuels make it unfeasible. More energy is needed to produce the fuel than is gained by using the fuel. However, on a larger scale, these numbers quickly reverse and biomass and biofuels become a highly feasible, renewable source of energy.
At the present time, the cost of collecting biomass and transporting it to a centralized processing station are higher than the costs of extracting fossil fuels from the earth. For this reason, the use of fossil fuels will likely continue to be predominate until their supplies are nearly completely exhausted.
However, creation of local biomass processing plants and power generation plants can eliminate the need to have vast pipelines or to move fuels by truck or train from one place to another. If the energy is used in the same area it is produced in, the cost of the energy decreases dramatically.
At the present time, the costs of producing biofuels in the form of alcohol or biodiesel are higher than the costs of extracting and refining petroleum and transporting the fuels produced to where they will be used. However, studies are being conducted on finding different sources of the starches needed to break down into sugars and ferment to produce this alcohol. Cellolose alcohol is being studied very heavily because using the entire plant, rather than just the grain, may be a way to make it more economical in the long run.
Biodiesel produced from vegetable oils and animal tallow is almost identical to petroleum based diesel fuel in terms of the amount of energy it produces and how it burns in an engine. The emissions are much cleaner with biodiesel, but the cost is almost three times the cost of conventional diesel fuel. The benefits of using biodiesel should outweigh the costs over time, but in the short term, it is not seen as a feasible substitute at the present time.
Understanding the costs of biomass and biofuels is one key to unlocking their potential for use as replacements for fossil fuels. Work is ongoing in an attempt to make production of biofuels more efficient and more cost effective.