Scientists have been warning the world for many years that the fossil fuels we rely on so heavily for energy are a finite resource. The search has been going on for renewable sources of energy to replace them for several decades. One of the more promising options for obtaining energy has proven to be biomass, fuel created from living or recently dead organisms. However, there are some biomass disadvantages as a source of energy.
The first, and possibly worst, disadvantage of biomass energy is that burning biomass directly as a fuel produces more greenhouses gases than can be absorbed by remaining plants, making it a hazardous contributor to global warming.
Combustion of biomass as a fuel also consumes it at a much faster rate than it can be replaced. This means that biomass is, in and of itself, not a very efficient source of energy. However, with the addition of a small amount of energy, biomass can be converted into a different fuel, alcohol or methane, that is relatively clean burning and yields more energy than the original mass going into the process.
This does mean, though, that biomass has the disadvantage, at least on a small scale, of yielding a negative amount of energy. This means that more energy must be added to produce a viable fuel and that the amount of energy yielded by that fuel is not equal to the energy that went into making it. The only way to overcome this disadvantage is to work on a large enough scale that the energy added works on a larger quantity of biomass at the same time, yielding more usable fuel and energy.
Collection of biomass that is feasible to use for creating fuel is difficult. There is simply not an abundance of dead plant or animal matter available in any one location that can be used as fuel or broken down for conversion to a more efficient fuel. This means that someone must expend energy and take time collecting biomass into one location before the process of converting it to fuel can even begin.
Though biomass is a renewable resource, there are limits to how quickly it can be replaced. If people harvest trees for use as fuel or to convert into other forms of fuel, those trees will take many years to replace with more trees of equal size. This means that we must focus our efforts on using plants, grains, and other forms of biomass that can be replaced quickly and inexpensively.
Biomass is showing great promise as a source of energy to replace fossil fuels being consumed in today's world. It has the potential to yield fuels that burn cleaner than existing sources of energy and yield more, renewable energy.
However, biomass disadvantages as a source of energy must be overcome before it will be a completely reliable source. More studies are ongoing to determine what forms of biomass will yield the greatest amount of energy and be quickly renewable so that man will not be without energy when fossil fuel supplies are exhausted.