In the spirit of trying to blog a little more, I just wanted to throw out one that I didn’t have a chance to post as a comment to a recent Transterrestrial post by Sam Dinkin. In his post Zero Divided By Zero = Space Solar Power, Sam wrote:
To focus on one link in this chain, it will require launch prices to fall below three times manufacturing costs of solar for space solar to be competitive with Earth solar which would require launch costs of less than $500/kg given solar manufacturing of about $170/kg now (and that is falling at 5%/year so it might be $150/kg that is the moving target to beat terrestrial solar in the 2030s).
While I agree with Sam’s basic point that Space Solar Power has far from proved its case, I did want to mention something. In all the discussions I see about space solar power vs. terrestrial solar power, many people rip on how for space solar power to be competitive, it has to be only three times more expensive then terrestrial solar power. And this is because space solar power on average only receives about three times as much power as a terrestrial station. The problem is that little word there–average. One of the major benefits of space solar power is that it is extremely consistent. No need to worry about clouds or other inclement weather, no night-time (especially in the right orbits you can supposedly eliminate even very brief earth-caused shadows), 24-7 consistent power output. Terrestrial solar isn’t constant enough to serve provide baseload power. Terrestrial solar also doesn’t do a lot of good during primetime (which is long after the sun has set). But space solar power can handle both of these situations. Which means its value is greater than the simplistic case made before.
Not that I think that this makes space solar power the best thing since sliced bread or anything. Just thought that the line of argument being used wasn’t entirely fair or accurate.