Solar Power From Space

I have a bias toward space-based solar power. I wrote a paper on it while I was in college on alternate energy source. Hence, articles like this get my attention:

Japan to try beaming solar power from space in mid-decade

A new global race is heating up to develop technology for transmitting solar power collected in space to Earth, with a Japanese public-private partnership aiming to run a trial around fiscal 2025.

Space-based solar power was proposed by an American physicist in 1968. The concept is to launch solar panels into space to generate electricity at an altitude of 36,000 kilometers.

At this time I’m inclined to believe it will not be competitive with other sources. The greater availability of solar and higher intensity of the solar energy in space does not appear adequate to compensate for the higher conversion and transmission losses compared to land based solar. And that doesn’t even compare it to the best terrestrial sources such as nuclear and hydroelectric power.

Still, I’m interested to see the results. Perhaps it will be useful in some special cases such as quickly getting power to remote locations.


13 thoughts on “Solar Power From Space

  1. I’ve thought about this a great deal in my youth. I think the only way it works is to use the power in space to produce a product, say, hydrogen and oxygen from water, and drop ship the product to earth in large shipments.

    I think we missed our window to do this sometime in the 70s or 80s. It’s too late now, it’ll have to wait for the collapse, and slow climb to the *next* industrial revolution, likely thousands of years from now.

  2. I suspect this will be advantageous for non-obvious reasons. For example, the Japanese have limited real estate for large-scale solar power collection (unless they use the sea). Orbital collectors could give them more elbow room.

    There are other factors I didn’t think about when I was breathlessly reading Gerard K. O’Neil as a teenager. Solar collection technology is still progressing… and replacing solar cells on the ground is a LOT cheaper than doing so in orbit.

  3. Basically what this amounts to is replacing solar energy collectors by microwave energy collectors. Apart from conversion losses, that makes sense only if the power density (at the earth end) is substantially higher for the latter case. Is that doable?

    The idea got some nice coverage in the wonderful SF novel “Fallen Angels” by Niven, Pournelle, and FLynn. It’s a wonderful exercise in poking fun at enviro-nuts; one of the plot elements is that the warmists have been so successful that the world is now in the grips of a rapidly advancing ice age, with Fargo already under the ice and Milwaukee threatened. But Winnipeg is still safe because it’s the earth end of a microwave space based solar system — essentially they are living in a large microwave oven. (Interesting — it’s on line:

    • that makes sense only if the power density (at the earth end) is substantially higher for the latter case.

      Average density over an entire day might be higher. But I think there are other issues to consider.

      • The microwave collector probably would be cheaper than the earth based solar collector.
      • A microwave collector could be installed in a low sunlight area, such as Seattle, or maybe even as far north as parts of Alaska.
      • Moving the energy from, say California to Texas, would only require redirecting the beam without significant transmission losses.
      • I don’t think that’s going to work: Microwaves find clouds nearly as opaque as sunlight does. Microwaves are easily absorbed by polarized molecules like water vapor, which are then heated… that makes a thermal… that attracts birds… that’s horriblly inefficient.

  4. I’d like to see this applied to interplanetary transportation. Beam power to a ship that uses it to build and steer a magnetic field that propels the ship across the solar wind, and even collects those particles into a protective blanket shielding it from cosmic rays. Not a lot of acceleration, but plenty of time for that acceleration to build. Thrust for days or weeks at a time, rather than carefully measured seconds.

    How much does the faint solar wind disperse a microwave beam? I assume there are wavelengths less susceptible to dispersion than others, even immune to it.

  5. We already have a term for a solar array that beams a useful amount of power down to the surface.

    “Death ray”

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