Biomass (liquid)

E85

A fuel blend containing 85% ethanol and 15% gasoline.

E10

A fuel blend containing approximately 10% ethanol and 90% gasoline.

Flex Engines

Vehicles designed to run on ethanol-gasoline blends.

Biofuels

Fuels derived from biomass, including ethanol and biodiesel, contributing to ~2% of US total energy consumption.

Renewable Energy Growth

Significant increase in renewable energy use in the US during the 1970s and early 2000s, followed by stagnation.

Biomass Production Limits

The theoretical and harvestable limits of biomass production, with only a small fraction of energy used for cultivation and processing.

Leading-Edge Biomass

Innovative sources of biomass, including algae and cellulosic plants, for biofuel production.

Value Chain

The network of firms and organizations involved in biofuel production, influencing government policies through lobbying.

Energy Tax Act 1978

Legislation that promoted ethanol as a substitute for foreign oil due to high oil prices.

Clean Air Act 1992

Legislation that designated ethanol as an additive to reduce vehicle emissions.

Biomass Research and Development Act 2000

Act encouraging research and development in biomass through financial support.

Energy Policy Act 2005

Legislation aiming for 25% of US energy to come from renewables by 2025.

Renewable Fuel Standard

Mandate for large-scale ethanol blending in gasoline to reduce greenhouse gas emissions.

Land Energy Yield

Measurement of energy produced per hectare for various biofuel crops.

Criticisms of Biofuels

Concerns about the effectiveness and environmental impact of biofuels, particularly from maize.

Carbon Debt

The time required for biofuel production to offset carbon emissions from land clearing.

Environmental Impact

Negative consequences of biofuel production, including deforestation and increased fertilizer use.

Food Prices

The impact of biofuel production on food prices, potentially leading to food insecurity.

Renewable Fuel Standard Impacts

Increased corn prices and land use changes due to the Renewable Fuel Standard, affecting environmental quality.