Using plants, food waste and industrial waste to generate energy is pretty genius stuff. Biomass is a renewable source of carbon-based energy generated from combusting plant matter. But it's not perfect. The methods used in this process can cause significant environmental damage, just like other energy sectors. With another 3,500 biomass plants expected by 2020 worldwide, addressing the ecological concerns associated with this resource is crucial.
TL;DR (Too Long; Didn't Read)
Biomass is relatively safer for the environment than fossil fuels, but it's not totally innocent. It can have negative impacts on everything from soil to water resources to forests to the atmosphere and climate.
Biomass is plant-based material and waste that can be combusted in order to heat water into steam. The steam then spins turbines to generate electricity. The materials can come from virgin wood, energy crops, agricultural residue, food waste and industrial waste.
The ability to burn waste products from other industries to generate electricity makes biomass an environmentally friendly resource compared to fossil fuels. In the United States, biomass provides over 50 billion kilowatt-hours of electricity each year, amounting to over 1.5 percent of the total electricity demand.
Deforestation and Farming Practices
Biomass requires energy crops grown on a large scale. Grasses and other inedible, high-cellulose crops are the most common. These carry the same environmental impacts as food crops in terms of pest control, watering and erosion.
The removal of forest for the production of energy crops can also increase greenhouse gases; 25 to 30 percent of greenhouse gases released each year are a result of deforestation.
Mitigating these agricultural risks and impacts hinges on sustainable harvesting practices and responsible land use.
Like coal and nuclear plants, biomass plants may disrupt local water sources. Water use at a biomass plant ranges between 20,000 and 50,000 gallons per megawatt-hour. This water is released back into the source at a higher temperature, disrupting the local ecosystem. The nutrient runoff from energy crops can also harm local water resources as well. And growing energy crops in areas with low seasonal rainfall puts stress on the local water supply.
Despite being a relatively clean alternative to more harmful fossil fuels, biomass still generates harmful toxins that can be released into the atmosphere as it's combusted. Emissions vary greatly depending on the feedstock of the plant, but pollutants like nitrogen oxide, sulfur dioxide, carbon monoxide and particulate matter are common. Filters, cleaner biomass sources, gasification systems and electrostatic precipitators can help the issue.
Transporting waste from forestry and industry to a biomass plant also carries a significant carbon footprint from the petroleum used by transportation. This release of greenhouse gases may be a secondary environmental impact from biomass energy generation, but it's important nonetheless.