| For a comparison, suppose a photovoltaic solar energy system was spread out on the same 50 mile by 0.5 mile plot of land that my train system above might require. If the solar system had a 10% fill factor (only 10% of the area would have solar cells), a 10% conversion efficiency, 6 hours of sun per day it would generate 4.2 million kilowatt-hours or about 420 million dollars worth of electricity each day. Clearly for a given large area, the photovoltaic system produces more power. |
| If we can imagine a photovoltaic panel as big as the million square foot wind sail, each panel could generate 10 million watts. This figure is much less than a wind sail train at 30 MPH wind. But, at 18 MPH, the sail would be no better than the PV area. |
| A 250,000 volt, 3 phase transmission line should be able to carry about 500 million watts with a current of 1000 amps. |
1.356 joules = 1 foot-pound (pound of force x one foot distance)
1 joule = 0.7375 foot-pounds.
|
| So, 10,000 pounds of force applied toward a mass moved 250,000 feet would require 3.4 billion joules of energy. |
| If we wanted a sailtrain to generate 44 million watts of power for a period of 5 hours, the energy would be 44 x 5 = 220 million watt-hours or 800 billion joules. If the distance is 50 miles or 250,000 feet, then the pulling force on the train would be 3.17 million pounds. Clearly, a big rope would be needed for such a pull. It would require over 32 one inch diameter ropes, each rated with a tensile strength of 100,000 pounds. But, to withstand wind gusts, perhaps each rope would need to be rated at 1 million pounds |
