While wind power and ground solar power are renewable sources of electrical power, they are not continuous. This variability complicates their use to replace fossil fuels because wind and ground solar farms are not always producing electrical power and, when they do produce power, it may only be a modest percentage of the installed nameplate generation capacity.
Another major issue is that wind and ground solar power are quite diffuse. A typical commercial wind farm will only be able to produce sufficient electrical energy per square mile per year to meet the annual energy needs of about 200 Americans in 2100. Supplying the energy needs of 400 million Americans—80 percent of the expected 500 million Americans in 2100—would require 2 million square miles of wind farms covering roughly two-thirds of the contiguous United States. Obviously, this is not a practical solution.
Commercial ground solar farms, per square mile per year, could meet the annual energy needs of about 1600 Americans in 2100. Supplying the energy needs of 400 million Americans would require 250,000 square miles of solar farms. While this is less than required for wind farms, solar farms require flat or near flat land for the installation of the solar arrays. The sunny Southwest is the favored location for solar farms. However, in the seven southwestern states of southern California, Arizona, Nevada, New Mexico, Utah, and western Texas, only about 87,000 square miles is suitable for commercial solar farms. Like wind power, ground solar power is also not a practical solution to replace fossil fuels in America.
The disadvantages of America transitioning to wind and ground solar power to replace fossil fuels are discussed in more detail in the following narrated, 15-minute video.
What about terrestrial nuclear power?
A commercial nuclear power plant generates electricity by harnessing the thermal energy, released as uranium U-235 fissions, to boil water to produce steam to drive turbine generators. A typical commercial nuclear power plant generates about 1-GW of electrical power. Thus, to use nuclear power to replace fossil fuels by 2100, the United States would need to build roughly 4,000 1-GW nuclear power plants. For comparison, today, the United States has about 100 GW of nuclear generating capacity.
Besides issues related to safety, location, and nuclear waste disposal, the United States does not have sufficient uranium to fuel 4,000 plants. A new nuclear power plant is expected to operate for 120 years. Optimistically, the United States has sufficient remaining technically recoverable natural uranium to fuel 100–150 1-GW plants for 120 years.
To increase the fuel supply, the United States would need to turn to breeding fuel. If the United States pursues this approach for replacing fossil fuels, other industrialized nations will likely do the same. Each plant will require that about 2000 pounds of plutonium or U-233 be bred each year for fuel. Thus, the United States would need to breed 4,000 tons of these weapons-capable fuels each year. The world, would need to breed about 50,000 tons per year. The potential for diverting some of this production to make nuclear weapons or dirty bombs would be a serious concern. Thus, in addition to safety, location, and nuclear waste disposal issues, the nuclear proliferation threat means that such a large-scale use of nuclear power is not a practical solution for the United States or for the rest of the world.
The disadvantages of America transitioning to terrestrial nuclear power to replace fossil fuels are discussed in more detail in the following narrated, 15-minute video.
While many casually assume that wind, ground solar, or nuclear power will enable the United States to replace fossil fuels, quantitative examination yields a different conclusion. Only GEO space solar power has the potential to replace fossil fuels with sustainable electrical power.