1. Not Totally Clean When Burned: The biggest contention against biomass as a clean energy is the pollution that is created from burning the wood and other natural materials.
2. Can Lead to Deforestation: Wood is a major source of biomass energy. To produce considerable amount of power, large amount of wood and other waste products have to be burned. The desire to produce energy on a large scale can lead to deforestation that would destroy the homes of large number of plants and animals.
3. In-efficient: Biodiesel product like Ethanol which is produced by biomass is relatively inefficient as compared to gasoline. It has to be mixed with gasoline so that it can be used in combustion engines. Apart from that, long term usage of Ethanol can be harmful to the engines.
4. Requires Lot of Space: It’s hard to find a plant that is in a convenient place. Many times, biomass energy plants are found in urban areas, which means that they are causing more traffic in those areas and they are causing more pollution, which seems to be more of a problem than an actual help.
5. Expensive: The last problem that often comes up is how expensive this process is. The production of biomass plants is incredibly expensive and, in some cases, the costs are not worth the benefits. Transport and resource gathering expenses are high and will be continually needed every day. When you compare the process of biomass energy to fossil fuels, you find that the cost is actually much higher.
6.Harmful emissions Even though biomass energy production is carbon neutral it involves emission of other gases that can be harmuful to the environment. In specific, the production of biomass energy causes the release of nitrous oxide (N2O) and methane (CH4) that cannot be reabsorbed by simply replanting the biological material that was used. As a result Green House Gases accumulate during the production of biomass energy something that doesn’t happen with other renewable energy sources that can be completely clean.