If the collectors mass 1 kg/m2 and the rest of the system masses the same equally, then the total mass is ~5,880 tons. Delivery cost at $5,000/kg is $29.4 billion. Kind of excessive, but not utterly ridiculous for such a big space-based system. Clearly the way forward is system mass reduction. My 1 kg/m2 was deliberately excessive. What if we’re looking at 0.1 kg/m2? And $2,500/kg to GEO? Then the cost is ~$1.47 billion, perhaps double that for the whole system costs, including assembly.
How much could the power sell for? If we’re talking competitive with power sources on the ground then the cheapest cost for power is ~$0.04 /kW.hr. A 1 GW SPS (Solar-Power Satellite) provides 1,000,000 kW.hr/hr and might last ~30 years without major system replacements – call it 263,000 hours. Thus the wholesale energy market value is $10.52 billion at constant prices. No inflationary adjustment. End-users, like the suffering masses of my state Queensland, are paying $0.2/kWhr, thus an energy retailer would gather ~$52.6 billion in revenue over that period, non-inflation adjusted. So profits aren’t unimaginable for space-based power-companies to aim to achieve. Let’s assume space-lift is 25% total cost, thus the 1 GW SPS system has to cost ~$2.63 billion to get into orbit. That gives us a rough guide to the kind of mass-efficiency and space-lift price we want to see to make SPS a viable profit-making enterprise.
If Spacex can deliver on their promise lower launch costs by another five times, then the possibilities for commercial space based solar power look reasonable.