Activity Overview: Natural resources are not evenly distributed across the United States or even across the State of Texas. Looking at the horizon you can see if you are near the sea or surrounded by timber, but other resources crucial to our daily lives are less obvious. Each of the activities on this page references a different resource and provides resources your class can use to identify different sources of freshwater, fossil fuels, and renewable resources.

Time: This activity is part of a series on maps of natural resources. Each one takes about 15 minutes. You can schedule them in series or you can evaluate them as you discuss each resource in your class.

Procedure:

Bioenergy is one of the most important forms of renewable energy and has been employed for thousands of years. Cumulatively, bioenergy represents a greater fraction of the U.S. energy mix than any other renewable fuel source. Biomass solids are typically used for heat and power. Examples include wood, straw, cow dung, and waste. Biomass possesses a lower energy density than coal. While coal averages about 20 million British thermal units (Btu) per ton, organic biomass typically has 10 million Btu per ton. Biogas is similar to methane or natural gas, but with only 60% to 70% methane and a balance of CO₂. Landfill gas is a form of biogas, as is the output of anaerobic digesters and composters. Biofuels are liquid fuels like ethanol, biodiesel, and biobutanol. Biofuels are typically intended for the transportation sector, though they have a lower energy density than gasoline or diesel.

The National Renewable Energy Laboratory worked with collaborators from universities across the United States under the direction of the U.S. Department of Energy in order to illustrate the biomass resource. The maps are all available as part of the Biomass Maps online collection.

The map linked below shows the solid biomass resources by county for the entire country. Other maps are available through the maps collection. Use any maps to answer the following questions.

Ask students to answer the following questions:

• Which Texas county generates the most solid biomass per year? [Harris County]
• How many thousand tonnes per year of solid biomass does Austin, Texas, generate per year? [between 150 and 250 thousand tonnes per year]
• Which state generates the highest quantity of urban wood waste per year? [answers may vary between California, New Jersey, and Massachusetts]
• What is the average primary mill residue for counties in Texas per year? [greater than 100 tonnes per year]
• Which of the following states has the greatest crop residues per year?
  • Iowa
  • Florida
  • Utah
  • New Hampshire