An economic assessment is pretty hard you have to admit. I did mention the objective is to make a solar power satellite much smaller through the use of concentrating lenses. I quote from my paper:
"The example design consisted of a 600-meter diameter Fresnel lens made of type-214 quartz in a close polar orbit around the Sun, a 600-meter diameter relay lens located at the L1 Lagrange point, a 600-meter diameter reflector lens orbiting Earth, and a solar thermal co-generation plant located in the middle of the Pacific Ocean. The Fresnel lenses would operate near their material softening point, and the ocean platform would operate at a temperature ideal for generating steam. This design could generate up to 518 gigawatts of usable, uninterrupted electricity for public use, and 1538 gigawatts of heat for distillation of cellulose ethanol fuel for transportation. For comparison, an equivalent solar powerplant consisting of photovoltaic or solar concentrators in Earth orbit would have to be approximately 49 kilometers in diameter to deliver the same amount of electricity, and would be entirely composed of expensive high-quality mirrors or photovoltaic panels. Each 600-meter diameter optical lens therefore represents a 6705-fold reduction in surface area for a solar power satellite. Since reducing a spacecraft size often reduces its mass and cost, the use of a Fresnel lens to transmit collimated solar energy directly from the Sun’s corona to Earth may prove to be a significant advantage for space-based power generation."
So, this design could be several thousand times less expensive than an equivalent photovoltaic solar power satellite, just because it is so much smaller. Plus the size, though large, is still within reason. So there is a small possibility that it could be built, as opposed to none at all. Further cost estimates are difficult, obviously a great deal of design work still needs to be done. One would have to create a detailed design, right down to the nuts, bolts and paint job, to really estimate the cost. Seriously, I'd love to be paid to design it for real. At the moment it's a hobby.
