An Overview The United States' Energy Situation
Module1: US Energy Overview
Module2: US Energy Production Breakdown
Module 3: Simulation of US Energy Independence
Based on the report Case Study of Current Domestic Energy Deficit in the United States and Simulated Solutions for Filling the Deficit by Utilizing Renewable Resources and Other New Technologies, J.A, Werner, R.M. Lyman, N.R. Jones Wyoming State Geological Survey Coal Section, aka "case study".
The authors present a simulation to look at a mix of domestically available energy sources to fill a 19 QBTU energy deficit (from energy independence). They pick 19 QBTU since the assume that nuclear energy will automatically grow by an additional 8 QBTU by the time this simulated scenario is realized. This means that the actual shortfall (as of 2003) is 27 QBTU. We will just refer to the 19 QBTU shortfall as 70% of the total shortfall, and assume that nuclear, other, or imported energy will make up the 30% shortfall. It appears that as of 2007, the output of nuclear power in the US has not changed substantially since 2003.
Figure 12 shows the simulation arrived at in the case study. Note that this pie chart includes the additional 8% of nuclear power generation (shown as 17% of total energy use on the left pie chart) as well as an additional 8% as part of the simulated solution. Note also that transportation fuel (portable liquid fuel) is not addressed. The case study notes that some petroleum used in non-transportation sectors will need to be shifted to the transportation sector.
FIGURE 12: Simulated Energy Solution per Case Study
The most interesting part of the study is the series of maps showing how much land will be required to achieve 19 QBTU (remember this is about 70% of the shortfall) for each type of alternate energy energy. Obviously no one energy source is chosen, buit rather a combination. Note that nuclear energy was covered in Part II of this report.
Figure 13 shows the land area required to achieve a 19 QBTU shortfall using current photovoltaic solar cells. Roughly the entire state of Colorado would need to be utilized. The case study indicates that the [current technology] solar option is very expensive, but that placement on some private residences would be feasible.
FIGURE 13: Land Use for a 19 QBTU Solar Installation
Figure 14 considers a switchgrass (non-food source) biofuel option. The large square is the land requirement for ethanol production from switrchgrass, while the smaller inner square would be for direct firing of dried switchgrass fuel. The conclusions are clear. First, direct fire is more efficient, but neither is feasible for the full 19 QBTU shortfall.
FIGURE 14: Land Usage for Annual 19QBTU Switchgrass Production- ethanol and direct fire
Finally, Figure 15 illustrates the land required for harnessing wind to generate the 19 QBTU annually using 1.5 MW turbines. The actual sites shown were proposed in a study by Elliot et. al., "Wind Energy Resource Atlas of the United States", so represent viable locations. Similar to solar, the case study concludes (regarding wind energy), "individual utilization of wind energy is much more practical than commercial utilization. Incentives and tax credits to small businesses and homeowners who incorporate wind or solar derived energy will help tremendously to spread the burden of cost."