# What is a reasonable cost estimate for space solar power (SSP)? [closed]

What is a reasonable cost estimate for the following:

1. A single space solar power station beaming power to earth via laser or maser and one associated receiving station?

2. The following complex: A moon colony used to mine material and launch it into space, presumably with a solar powered electrically driven ramp, an orbital station used to construct space solar power satellites and enough solar power satellites to meet 50% of the USA's electrical needs along with associated ground stations.

I saw an estimate, 30-40 years out of date, of trillion dollars for #2. Unfortunately, I cannot recall the source of this estimate.

• The National Space Society is a avid supporter of space solar power. There's a great bunch of links on their page here. Commented Feb 11, 2015 at 2:22
• I believe most space based solar power architectures beam the power to the surface via microwaves and a rectenna.
– Erik
Commented Feb 11, 2015 at 4:31
• New Scientist had an interesting article (possibly need a subscription to read full article) on orbiting solar power plants recently. Commented Mar 15, 2016 at 8:36
• the corollary would be the value of the energy. Commented Dec 14, 2016 at 12:17

You probably read an Omni story, or "The High Frontier: Human Colonies in Space" by Gerard K. O'Neil (also wrote a nice General Relativity book). There is a 2013 book, Spaced-Based Solar Power System Architecture by Brain C. Busch (Naval Postgraduate School). That might have some good stuff.

The numbers back then looked good to some experts and impossible to others. I have not seen much serious work in ages. I fiddled around once and found that an underground (undermoon?) habitat with 1 atmosphere of air pressure could hold up 30 feet of lunar regolith on the air pressure alone. So huge underground habitats are possible from a simple engineering point of view.

The power sat does not need laser or maser. Simple microwave arrays that maintain coherence from feed back from the receiver are fine. They could use robust tubes (without the tube) instead of semiconductors. The idea is that if the sat power wondered off the target area the coherence is lost and the beam spreads out enough to be harmless.

I always liked the idea. The Luddites and Greens won't because the power comes from off-Earth and will contribute to the total heat content of the atmosphere. On the other hand, if construction takes place in Lunar orbit, you save on all that. The trade-offs are many and depend on politics and the current thinking on warming/cooling, which is subject to change any time now.

• Your comment on heat content is telling (+1). At some point we are going to have to man up as a species and accept the fact that we will have to engineer the climate. This will probably require megaengineering projects of the likes we have never seen. What could possibly go wrong.
– Erik
Commented Feb 12, 2015 at 6:12
• However as I also commented on this answer burning fossil fuels also adds direct heat to the environment as well as addding CO2. Space solar adds direct heat, but doesn't add CO2, as such it does not contribute to the greenhouse effect, making it much superior to fossil fuels. Commented Feb 12, 2015 at 10:19
• CO2 may not be doing anything either. There have been periods in the past when it was far far higher than today. That aside, we may have no choice but to use massive fossil fuel power to get over a technology hump to a better source that can raise most of humanity to the quality of life of the U.S. We need rare earths magnets and other materials that require giant mining and transport machinery. Once you can run that entire infrastructure on electricity you might be on the downhill side to get to the destination that many want. Commented Feb 12, 2015 at 17:08

John Mankins is one of the top SSP researchers today. In an interview he said that he could put together an SSP "pilot plant" (in orbit) given ten years and \$10 Billion. I'm not sure what the size of the plant would be, but it would be a full system architecture technology demonstrator that could then serve as the blueprint for additional commercial scale facilities. A working moon base with resource extraction, refining, and electromagnetic launch to supply materials for space colonies and SSP systems? Likely trillions. You may have read "Colonies in Space" by TA Heppenheimer. It was based on the work of Glaser and a grad student summer study. Of course as solar cell technology gets better and launch costs drop, we should eventually reach the price point where SSP makes sense to everyone. I'm surprised Elon Musk has talked so much about Mars and never mentioned (to my knowledge) Space Solar Power, because the first SSP projects may very well launch on recycled Falcon 9s.