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lughnasadh OP t1_ixi3hzd wrote

Submission Statement.

The European Space Agency formally committed to a feasibility study on space solar at their big annual meeting in Paris this week. ESA specifically referenced baseload electricity generation in their reasoning for supporting this idea.

Personally, I don't get it all. Research & deployment in many different types of grid storage batteries is racing ahead at the moment, and this will be space-based solar's main competitor. It seems hard to believe it will ultimately ever beat it on price.


TheRealCBlazer t1_ixigb0c wrote

Seems like a great idea to me. The Earth's atmosphere, distance from the sun, rotation, and seasonal tilt dramatically reduce the effectiveness of surface-based solar. All other forms of energy harvested on Earth (fossil fuels, etc.) are just various different inefficient forms of solar power, with significant losses in the efficiency of collection and transmission (e.g., biological and geological processes).

But a panel in close solar orbit can receive a much greater flux with nearly 100% uptime. Energy collected from close solar orbit can be beamed not only back to Earth, but also anywhere in the solar system (Mars, the moon, the asteroid belt). The resources to construct such systems are available in zero-g or micro-g environments (e.g., in the asteroid belt), so we would not have to mine the Earth or overcome Earth's gravity well to manufacture and deploy them. Space-based solar energy collection and transmission can be the backbone of a system-wide energy grid that essentially leaves Earth untouched.


[deleted] t1_ixijpjk wrote



TheRealCBlazer t1_ixinkng wrote

But with the ability to beam power anywhere in the solar system, you don't need to launch from Earth. Everything can be mined, refined, manufactured, and deployed in zero-g or micro-g.

The Earth-based outlay would not be in the form of close solar orbit panels. It would be self-replicating machinery deployed to the asteroid belt. Possibly even deployed from Earth's moon (which admittedly still traces back to initial launches from Earth). But the vast bulk of the grid would not be launched from Earth.


[deleted] t1_ixip9ck wrote



TheRealCBlazer t1_ixiqc2m wrote

The idea is to mitigate global warming by moving as much resource collection, refining, manufacturing, and energy production into space, asap. This is not hyper future tech. I speak on this personally, because it was mine and my professor's area of focus in electromagnetics and electrodynamics in 1997. Of course, it takes time, money, and will to implement, which the Chinese are now doing. These first steps are not the final product, but they are necessary to get there, and I'm glad someone is finally doing it. You're right about the fact that we've waited far too long already.


jhev1 t1_ixiso6d wrote

>The idea is to mitigate global warming

By the time this tech is a reality the earth will be well past the point of no return, which is projected anywhere from 10 to 75 years


isleepinahammock t1_ixizels wrote

Also, consider that rockets themselves emit lots of CO2 as they launch. Sure, you can use a hydrogen/oxygen rocket, but then you need a source for hydrogen. And if you don't want greenhouse emissions, that means you need a huge plant cracking water into H2 and O2. In other words, you effectively need to build a huge energy storage facility. You could just attach a fuel cell to your rocket H2/O2 plant and skip the rocket launch entirely. It is possible to create green rocket launches, but the equipment needed is essentially already a massive base load solar/wind plant.


ItsAConspiracy t1_ixjg980 wrote

A Falcon Heavy costs $90M for up to 141,000 lbs to LEO, for a total cost of $638/lb. And the Heavy isn't fully reusable, so the main cost is the upper stage that gets thrown away. If Starship or something similar works out, the price will drop to about $30/lb. At that price, space solar starts to make sense.

I plugged that number into the cost estimates from the book The Case for Space Solar Power, which has detailed numbers based on NASA's SPS-ALPHA project, and it came out to 4 cents/kWh including everything (manufacturing, ground station, etc), which is pretty great for clean power on demand without needing storage.

Starship is fueled by methane which can be made pretty easily from water and CO2. With a clean energy source, the whole project could be carbon neutral.


PowerfulMilk2794 t1_ixjhbi1 wrote

If Starship can bring that cost down to 10 per lb the economics start to look feasible. Big if, but this is Futurology after all.


Awkward_moments t1_ixl09jd wrote

>Energy collected from close solar orbit can be beamed not only back to Earth, but also anywhere in the solar system (Mars, the moon, the asteroid belt).

What size beam divergence are you expecting at these various distances?


politepauly t1_ixppvl9 wrote

well it's how the Dyson Sphere tech starts, Except that humans are 5,000+ years behind the rest of the universe. We're pretty pathetic.