No night? Where are you putting these satellites? The only orbit that doesn't eclipse is sun synchronous, an already crowded orbit. Even GEO satellites experience eclipse.
The article addresses this. To my mind 4 minutes per year is equivalent to the parent’s layspeak “no night” comment.
Why?
- You still get better duty cycle from the panels
- The time the power is missing is very small
- The need for storage, etc, is low because it's a short period of relatively low demand that is missing.
The moon is 10x further away, so the Earth subtends/shades a much smaller angle.
You can chalk my comments up to a grumpy engineer tired of the cyclical SBSP pushes that never go anywhere.
Here the only thing it's going to drive are thermal requirements-- which are admittedly significant problems. There's no need to continue to use large amounts of power for comms, etc, like on most GEO birds.
And, of course, the grid needs to deal with the power disappearing for an hour in the middle of the night for short periods of the year.
But you do need everything to survive the cold and thermal cycling.
You'd need propulsion to maintain position and orientation. You'd also need a number of propulsion units to balance solar pressure gradients as the collector entered and existed the Earth's shadow as well as the thermal expansion/contraction of the structure.
It's likely not a lot of power but a non-trivial amount of fuel.
High-impulse ion engines, etc, are a good match for this task.
A structure 100m on a side would be just at the bounds of current technology (the ISS's control moment gyros). With 30% efficient panels that's only about 4MW before conversion and path losses.
The high impulse ion engines to desaturate the gyros would still need to be refueled regularly. I think you're hand waving a lot of complexity that even if completely solved still leaves a solution that's orders of magnitude costlier than solar panels on the ground.
As to power disappearing with an adequately geographically integrated grid I don’t forsee that as really too much of a problem. Currently the grid deals with short term outs fairly well especially if they are planned for months in advance.
Lots of thin structure with 70 minutes to radiate, with the only thing shining on it the earth's albedo subtending a tiny angle. I'd imagine it creates rather significant demands on structure and electrical connections.
I've not run the numbers on a GEO solar spacecraft, but the smallsat group that I'm mentoring that would be "thicker" than a lot of the GEO craft... gets down to -30C without heaters during its 40 minutes in eclipse while much closer to Earth.
> As to power disappearing with an adequately geographically integrated grid I don’t forsee that as really too much of a problem. Currently the grid deals with short term outs fairly well especially if they are planned for months in advance.
Yup, that's the point I'm making. A space based solar power craft has smaller problems from eclipse than a typical comsat. Batteries, etc, are not nearly as much of a concern. It's mostly the thermals that are left.
Have pizza: https://www.youtube.com/watch?v=lGDUmGlMJzU