Silly. We need what 0.02% of the earth's land for enough solar for the planet??? And that excludes water. So why pay more to put it in space? Too easy to do it on land?

There is a small advantage for solar collectors in geosynchronous orbit in terms of time in sunlight.

There is a small disadvantage in the sense that a high power microwave transmitter in geosych orbit can be used as a weapon of mass destruction.

[deleted]

It could be overall cheaper. What you also need for solar power on the ground is storage, storage, storage, and 10x the capacity, because you won't produce enough in the winter.

SBSP could go hand in hand with ground-based systems providing the necessary dispatchable baseload or peak power, enabling a truly renewable system without expensive backup power stations.

They receive 8 times more energy per year than ground-based solar power. Even if you lose 50 % during transmission you get a) 4 times the power than on Earth with the same capacity b) continuous power supply throughout the year.

And if anyone is going to be allowed to build a SBSP satellite, it will include power beaming designs which are inherently safe and cannot be used for "mass destruction".

​

How about using it to power the moon base or rovers first, who otherwise remain in the long cold night of the moon?

[removed]

If you are promoting your own article you should probably just say so...

How long will it take to get the same amount of energy back to Earth from 1 tonne of solar arrays as it costs to get that 1 tonne to the relevant orbit?

If the answer is a year, then yes. If its 20 years then unlikely.

Energy cost will be your hard floor, if it takes too long to get the energy back then you are wasting your time. Above that comes the economics, how much can you get from consumers for 1 tonne on orbit vs the cost of getting it there. This is a bit more flexible as you can work on the non fuel costs.

Space does offer advantages, you can almost always be at 90^(0) to the Sun and you can have less atmosphere to get through. Its also almost always very sunny. It has disadvantages like the current insane cost to orbit and the difficulties getting energy once you move beyond the tropics and into more oblique angles.

The current answer is a very loud no with current technology. The point where no becomes yes is one of engineering and economics and an open question if you consider current costs to orbit easy to cut.

Well, starship is aiming to bring launch costs down to as low as 10 $/kg.

At that price SBSP would still be slightly more expensive than solar and wind, but much cheaper than storage, backup & peak load technologies which we will be needing in a purely renewable system anyway.

SBSP has the big advantage that it can deliver power to many markets, simply by switching to another base station. Thanks to this, it can capture much higher wholesale prices for electricity than wind and solar.

Essentially, it could capture 24/7 peak power prices, putting it at a better position than ground-based wind and solar even though it has higher levelised cost of energy.

I wasn't trying to promote it... 😔 I've just been down a whole rabbit hole the last weeks realising that ESA, Airbus, and Co. are all over the topic and I wanted to learn everything I could. There is even a government initiative in the UK now (https://spaceenergyinitiative.org.uk/).

I've been really excited about it and wanted to discuss with some likeminded people here, just sharing the background for those who haven't heard of it.

Didn't expect to be completely overwhelmed with 100 % underwhelmed reactions though. Really making me sad right now.

It's fine, but implying that you just found that article rather than wrote it is more than a bit disingenuous.

My personal take as an aerospace engineer is that I find it hard to believe that the benefit of better illumination outweigh the complexity and cost of a project like that.

Bunch of questions here, but starting with a couple...

What's your assumption on the cost of the distributed ground based plants accepting SBSP on a $/MW basis?

What's the breakdown of percent loss from SBSP for the transmission down to ground and conversion into usable AC?

[removed]

>I've tried to summarise what I was able to learn about it in this article :)

I literally wrote that I wrote the article myself.... 🙈

Yes, I get that. I'm an energy/mechanical engineer, and working as management consultant for the energy industry. It's a hard case. But the problem of renewables right now really is their intermittency... Solar PV has a load factor of 11-16 % over the course of the year, but in winter weeks you can easily get load factors of 1 %.

Space-based solar power can achieve close to 100 % load factor and delivers equally in summer and winter. From the value side, it provides much more than wind and solar do right now. But the cost side, of course, is also much more intensive. However, it appears to become economically feasible with launch costs decreasing further and further. If not as baseload than at least as peak capacity.

ESA is currently running two studies (results expected in the next months) which are expected to show that the cost of such a system could actually be further reduced if we were to use materials from the Moon.

>And if anyone is going to be allowed to build a SBSP satellite, it will include power beaming designs which are inherently safe and cannot be used for "mass destruction".

Where's the fun in that?

This doesn't feel like the right place for this. But to answer your question, no.

True, I'd love some death beams, too! 🤣

When I think of space lasers I think about using them to deflect asteroids. It would be kind of cool to beam them down to earth for power, but right now it's definitely not worth it. We could probably get the most bang for our buck by saving power.

It's around 50% at the moment, but has no physical limit really. The advantage of microwaves (like Radar) is that they are much less impacted by clouds and weather than visible light.

The receiver stations are also simple antennas which can be manufactured much cheaper than solar PV, therefore making up only a small share of the total CAPEX. I don't have the number off the top of my head, but they can be found in the Roland Berger and Frazer Nash studies.

I feel like you are oversimplifying things. 🤔

Probably easier to throw a small rock against the asteroids early on in their trajectory though :D

Right so the conversion is 50% but the transmission over distance is a distinct loss correct? Yes, microwaves can penetrate the atmosphere, but there is still a cost.

https://ars.els-cdn.com/content/image/1-s2.0-S2352484720317273-gr9.jpg

This diagram from a 2021 study touting a 45% conversion efficiency but notes a huge drop from the transmission... 400 KW -> 10 KW over just 10 KM.

When you consider geosynchronous orbit is all the way out at 35,000 KM. This seems like a major issue. What am I missing?

That there are only around 10-50 km of atmosphere is the way and that accuracy is the primary driver of losses. :)

That $10 per kilogram is an extremely optimistic estimate cited by a person who was well known to exaggerate in order to drive interest and investment.

Personally I suspect it's going to be quite a bit more than that, not that I'm an expert on launch cost. But I think we need to be a bit more skeptical of the claims being made at this time.

To the bigger question, I think any technology may be feasible in the future, but as far as I can see there's still a lot of challenges with orbital-based power. In particular the cost of sending it up and maintaining it, and the amount of power we can get generated back down on earth, and distributing that to a wide area.

But, if we don't come up with a better solution, it's definitely something I can see being in place in the next 50 or 100 years.

Hey OP question have you watched Isaac Arthur's video on power satellites?

I don't remember how much detail the video goes into, but there's links in the description for more reading and sources usually

Personally I think we will do some power satellites for Earth, but I doubt it becoming a major power component. My view is based on a lot of assumptions about the future though.

I'm not sure that there is a way to engineer something that would "prevent it being weaponised".

Nation states are likely prohibited by treaty from putting one in orbit, not sure why a private company should be allowed to do so.

In terms of using it for lunar colonisation the same problems arise but there's no treaties preventing it.

In terms of environmental benefit... all the power you lose forcing the microwave transmission through the atmosphere is energy that would not have been added to the Earth's budget otherwise. Attenuation in the air is drastically increased by water content, so cloudy / rainy areas are not great for receiving stations.

It's not a bad idea in principle and it's well within our capabilities from an engineering perspective but there is no world leader / private individual / council of wise pacifists I would trust with control.

Cheap bulk launch is a prerequisite, just like it is for lots of cool big space projects.

True. And we are strongly getting there. Cheap bulk launch is already here compared to 10 years ago. Where will we be in 10 years from now?

Or rather, according to EMROD, the main loss driver is the conversion to microwaves. Reconversion and transmission appear to be relatively efficient.

Still needs an order of magnitude more bulk, more cheapness. Starship is one to watch.

Absolutely. But Spacex won't remain the single cheap reusable launcher. Competition will catch up and then the real race begins.

Starship could pioneer the way for space based manufacturing, making it possible in the near future

[deleted]

[removed]

Yes, but I'm thinking we could reach it faster, and from further this way, and apply more energy in total. I'm not suggesting it would be worth it, more that it's a fun thing to think about.

True. And it might be worth it overall. Like, a laser would evaporate ice and material on the asteroid, which would push away from the asteroid, changing its trajectory.