I was talking about having mass in orbit from mined asteroids (or the moon), like the grandparent comment. This survey is based entirely on launched SBSP:
> This study assessed lifecycle cost and emissions based on the following scenario: SBSP systems are developed on the ground in the 2030s and launched to low-Earth orbit (LEO), and then transferred to and assembled in geostationary orbit (GEO) in the 2040s.
Furthermore, one main benefit of SBSP over nuclear is that the receivers don't need to be connected to the grid; each household or piece of infrastructure can have one. This would help manage situations like the power outage in Spain earlier this year or the situation at the start of KSR's Ministry for the Future where a deadly heatwave in India is made 10x worse by coinciding power outages.
No. The best thing you can do with a lot of mass in LEO is construct solar power stations that beam energy down to Earth in the form of microwaves. This is what the second book, Critical Mass, gets into. Receivers on Earth wouldn't provide as much power as solar, but would be much easier to construct and work 24/7, no matter the weather. This would be highly useful for reducing climate change and increasing climate resilience.