Fuels like wood, diesel, and natural gas have shaped human energy history, driven by technological, economic, and environmental forces. Liquid fuels from oil, with their high mass and volumetric energy density, led to their supremacy in transportation. Shifts in fuel types also influence the devices that convert them into energy services.
Biomass, derived from plants and animals, is a renewable energy source. The National Renewable Energy Laboratory mapped biomass resources in the US, including crop residues, forest residues, primary and secondary mill residues, and urban wood waste. These resources are used for heat, electricity, and fuel production. The maps offer county-level data for these resources.
Biomass generates electricity, or biopower, from sources like wood, agricultural residues, and urban waste. In the US, it accounts for 1.2% of electricity.
Approximately 91% of transportation energy globally comes from petroleum fuels, creating 29% of US and 20% of global greenhouse gas emissions. Biofuels offer potential emission reductions but raise land use concerns. Ethanol’s carbon emissions have decreased, and ongoing research aims to further reduce them. Government support and investments are driving biofuel expansion.
In the United States, ethanol is mainly produced in the Midwest from corn, with Iowa, Nebraska, and Illinois leading in capacity. Ethanol is used as a fuel additive, with E85 being a high-level ethanol-gasoline blend used in flex-fuel vehicles. Biodiesel, made from vegetable oils and animal fats, is mainly produced in states with these feedstocks. Renewable diesel, chemically identical to petroleum diesel, is primarily used in California to meet emissions regulations.
As of January 2023, 575 utility-scale biopower plants were operational globally, with a total capacity of over 29,000 MW, less than 0.5% of worldwide power generation. An additional 6,000 MW are under construction. China is believed to significantly underreport its true biopower capacity, perhaps as high as 22,000 MW, primarily from agricultural residues and waste-to-energy facilities. Brazil, another major player, relies largely on sugarcane byproducts.
Biopower is the production of electricity from biomass-derived fuels, with significant growth in Brazil due to sugarcane-based ethanol byproducts, while in certain regions like the United States, Germany, and the United Kingdom, waste-to-energy facilities are used due to land constraints and landfill opposition.
The use of biomass by humans can be traced back at least 1 million years to the controlled use of fire. However, the generation of electricity from biomass, known as biopower, is a more recent development. One of the earliest biopower plants was the São José da Estiva power station in Brazil, which began operating in 1900.
Biopower is electricity generated from renewable organic materials, such as plants and animals. Different countries rely on various biomass sources, including sugarcane, trees, and municipal waste, to produce biopower. However, the impact of biopower on climate change is complex. Despite being initially perceived as carbon neutral, the use of fossil fuels in bioenergy systems and the land requirements for biomass production can have significant environmental consequences.