Cost Estimates For A Space Elevator
For a space elevator, the cost varies according to the design. Bradley C. Edwards received funding from NIAC from 2001 to 2003 to write a paper, describing a space elevator design. In it he stated that: "The first space elevator would reduce lift costs immediately to $100 per pound" ($220/kg). However, as with the initial claims for the space shuttle, this is only the marginal cost, consisting of the electricity required to lift the elevator payload, but not operating overhead and maintenance; whereas the fixed costs would be US$6 to 12 billion, for construction; and one-way designs (such as Edwards') will add to the cost of the elevators.
The gravitational potential energy of any object in geosynchronous orbit (GEO), relative to the surface of the earth, is about 50 MJ (15 kWh) of energy per kilogram (see geosynchronous orbit for details). Using wholesale electricity prices for 2008 to 2009, and the current 0.5% efficiency of power beaming, a space elevator would require USD 220/kg just in electrical costs. Dr. Edwards expects technical advances to increase the efficiency to 2%. It may additionally be possible to recover some of the energy transferred to each lifted kilogram by using descending elevators to generate electricity as they brake (suggested in some proposals), or generated by masses braking as they travel outward from geosynchronous orbit (a suggestion by Freeman Dyson in the 1980s).
For the space elevator, the efficiency of power transfer is just one limiting issue. The cost of the power provided to the laser is also an issue. While a land-based anchor point in most places can use power at the grid rate, this is not an option for a mobile ocean-going platform. A specially built and operated power plant is likely to be more expensive up-front than existing capacity in a pre-existing plant. Up-only climber designs must replace each climber in its entirety after each trip. Some designs of return climbers must carry up enough fuel to return it to earth, a potentially costly venture.
Read more about this topic: Space Elevator Economics
Famous quotes containing the words cost, estimates, space and/or elevator:
“I knew that the wall was the main thing in Quebec, and had cost a great deal of money.... In fact, these are the only remarkable walls we have in North America, though we have a good deal of Virginia fence, it is true.”
—Henry David Thoreau (1817–1862)
“And, by the way, who estimates the value of the crop which nature yields in the still wilder fields unimproved by man? The crop of English hay is carefully weighed, the moisture calculated, the silicates and the potash; but in all dells and pond-holes in the woods and pastures and swamps grows a rich and various crop only unreaped by man.”
—Henry David Thoreau (1817–1862)
“Not so many years ago there there was no simpler or more intelligible notion than that of going on a journey. Travel—movement through space—provided the universal metaphor for change.... One of the subtle confusions—perhaps one of the secret terrors—of modern life is that we have lost this refuge. No longer do we move through space as we once did.”
—Daniel J. Boorstin (b. 1914)
“The cigar-box which the European calls a “lift” needs but to be compared with our elevators to be appreciated. The lift stops to reflect between floors. That is all right in a hearse, but not in elevators. The American elevator acts like the man’s patent purge—it works”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)