Biomass is an often misunderstood form of energy. Most people believe it has to do something with turning compoast back into energy through the latest in technology, but biomass has been used as a source of energy for millenia. Most cultures have been dependent on biomass alone until the advent of hydrocarbon production, where they simply burned firewood to heat their houses and cook their meals. Today, in its modern form, most biomass electricity is produced via a steam cycle, where organic material is burned directly or in "refined form" (biofuels) to produce steam to rotate a turbine. Used for fuel are:
- Residues of wood and paper processing.
- Residues from food production and processing.
- Trees and grasses.
- Gaseous fuels produced from solid biomass, animal waste, landfills.
Some developing countries arestill up to 90% dependent on bio fuels. 30% of the world population does not have or cannot afford electricity, so they have to substitute with their energy source of choice - biomass. There is a direct link between poverty and dependence on this form of energy. It is mainly used in the following countries:
- Sub-Saharan Africa.
As with most other forms of energy, we would want to transform biomass into fuel gas to achieve higher efficiency. Biomass could be burned directly to power a turbine, but gasification before combustion is actually preferred, because the power output is much larger when a gas is burned. Power plants often co-fire biomass to reduce acid-rain producing emissions.
Advantages of biomass:
- Biomass is plentiful and can be re-grown.
- Biomass can be improved by planting marginal land with fast growing trees and special grasses.
- It stabilizes the soil and reduces erosion.
- Biomass is renewable and recyclable.
- Biomass stores solar energy.
- No ash-waste-disposal problem .
- Creates jobs in rural areas.
- Depletes the soil of nutrients. But the ash can be used as fertilizer.
- Reduction of biodiversity.
- Smoke emissions during combustion.
- Aesthetical reasons.
- Growing, harvesting, and shipping biomass are expensive.
As a consequence, most facilities using biomass for electricity production in the U.S. show that it could potentially substitute. Much research about how to improve this form of energy generation is also conducted. In isolated locations in temperate and tropical regions, biomass is a valid source for electricity production, as coal would be equally or more expensive.
Currently, 33% of energy needs of developing nations and 3% of developed nations are met with biomass. This percentage will decline in the future because the relative growth rate of biomass energy is lower than that of commercial energy sources. Biofuels such as ethanol are not a valid alternative to gasoline because of competing use of crops and land in the U.S. and other food-growing nations. The Brazilian model (sugarcane grown on marginal land) is more promising.
Unless the prices of crude oil rise significantly in the future or government intervenes with carbon taxes and/or subsidies, chances for wide adaptation of biomass are slim to none.