Orbital Power Stations!
All the real estate there you could ever want. 9X the solar flux. Little or no "night". Direct delivery via lasers to any point in the hemisphere.
All the real estate there you could ever want. 9X the solar flux. Little or no "night". Direct delivery via lasers to any point in the hemisphere.
Where cost doesn't matter, everything gets easy.
The advantages of orbital are nearly 20X generation per panel to start with, even before considering support structures (none) and weather-proofing (none). That leaves lots of room in the cost equation.
Solar panels do not need to be "near major metropolitan centers". Modern transmission lines move power efficiently, silently, and reliably.
It would be impressive for your orbital panels to get out 4x as much energy as the light they intercept carries, but getting a patent on your perpetual-motion apparatus might be difficult.
Maybe do some elementary cost analysis. All the numbers are easy to find. Don't forget to figure in conversion loss from electric power on orbit to laser light emitted, losses scattering in the atmosphere, and conversion again from laser light received to electricity on the ground.
You would better loft many-square-km aluminized-mylar mirrors to reflect sunlight to solar farms on the ground. Keeping them pointing the right direction would be tricky.
Solar flux outside the atmosphere is 9X sea level. Go ahead, look it up. Then there's the periodic eclipse called 'night' that doubles orbital efficiency again. Look that up too.
Conversion losses of 20% seem normal? Both in orbit and on the ground. Which halves what you collect, well within the budget of 20X reducing it to around 10X.
Conversion losses of only 20% from electric to laser, and again from laser to electric again, would be miraculous. 20% scattering loss in clear weather would be unsurprising. 90% loss, total, would be admirable, not counting the original 60%+ loss off the top. So, even with 9x, and neglecting huge launch cost you still come out behind.
So about 75% of solar radiation reaches the ground. In the continental US, factoring in angle of the sun, average weather, night that comes to about 4-5KWh per day
In orbit you would have just 1.37KW X 24 hours (no weather, angle issues) which comes to about 33KWh per day. So that's 8-9X the collected energy per square meter in orbit vs ground level.
These folks https://www.allaboutcircuits.com/news/wireless-power-transmi... estimate 89% efficiency from orbit to ground.
So we're then at around 30KWh effective.
What am I missing?
So many things. The massive clear area around your receiver. Scattering induced by weather means you still don't have 100% capacity factor. With only radiative cooling available, cooling will take up as much space as the panels and make everything heavier. The atmosphere doesn't absorb light uniformly. Maintenance. You're comparing fixed panels at mid latitudes to rotating panels. Launch costs are still 10x the cost of a panel. UV and ionizing radiation will destroy your panels sooner. And a space borne panel will probably never reach net energy payback even before you add your laser boondoggle.
You're better off just burning the methane.
The land-based panels are 42lbs for 450W. The space-based ones are 6W per gram. Lots of room in the equation for cooling.
The 89% transmission already figured in weather and absorption; you don't get to count that twice.
Rotating panels get what? 25% better? Still an order of magnitude improvement.
Launch costs are dropping like a stone. Plan now; it'll be in the hundreds of dollars when you launch.
The slang about 'it'll never pay' is just talk. I'd hoped for some information, not just wet-blanket doubt.
Like the hot air about 9X being so far from the truth. Turns out, it's just about right. So I guess I'll have to look elsewhere for more information.
Somebody will make an orbital station, use it for space-based operations and all the hot air will disappear. And not that far in the future.
Land area is an absolute non issue for solar. With the exception of somewhere like luxembourg, just the roofs of the residential areas of a country have enough area to provide the total primary energy consumption. The singular and overriding factor is cost and cost of storing or moving the energy. Which brings me to
> The land-based panels are 42lbs for 450W. The space-based ones are 6W per gram. Lots of room in the equation for cooling.
You're not going to get nameplate capacity, and the weight is in the superstructure, cooling system, power delivery, and your 100s of metres aperture laser or maser. The actual panel for a terrestrial caravan system I installed recently weighed no more than the panels listed here https://www.spectrolab.com/DataSheets/Panel/panels.pdf (although it was bigger).
So you're proposing spending 10x as much on panels, another 10x as much on cooling, spending as much again on a transmitter, then as much again on a receiver. All to burn tens of kg of methane per watt in order to get the thing into a stationary orbit. Then you have a gigawatt death beam fucking up the atmosphere and making a square kilometer or so uninhabitable.
> Like the hot air about 9X being so far from the truth
Comparing like for like, you have about 1.3kW in space vs 1kW on the ground, and a tracking setup can get 6kWh/day out of a 1kW panel at low to moderate latitudes (where well over half of the world's population lives). This is a factor of 5 to 6 better, although your space based panel is vastly more expensive and a tracking system is pointless because cost is the limit, not area.
This is the most efficient high power long range wireless transmission system I can see mentioned: https://ietresearch.onlinelibrary.wiley.com/doi/full/10.1049... which brings the ratio to around 3-4. Except you also have to deal with losses due to clouds and dust so 2-3 is more likely.
At that point just build a nuclear plant. They're awful but they're better than this plan by every metric. Or do the sensible sane thing and build 100x the terrestrial solar for the same price (or 10x as much and enough storage) and save the space arrays for stuff in space -- once you're lifting megatons it makes far more sense to refine metals from asteroids and just leave 99% of them up there.
Or as I said, just burn the rocket fuel in a gas turbine. You'll get more energy out of it than you would from this utterly ridiculous machine in its lifetime.
If area was a constraint important enough to make space based solar viable we'd see water cooled triple junction cells as well as tracking on any utility scale installations near the equator (as this would reduce area by 2/3rds). We don't so it can be safely dismissed as more solar frickin roadways.
Orbital power is a total nonstarter if we aren't building the panels in orbit. Launch costs will absolutely destroy any ROI, even before you get into the transmission losses beaming the power back to Earth. SpaceX has completely revolutionized the launch industry, getting costs down to around $1200/lb. A typical solar panel weighs about 40lbs, but aren't optimized for weight. Assuming you can reduce this to 20lbs per panel that's still $24,000 per panel not counting transmission equipment and the like. The panel itself costs maybe $2000 for a very high efficiency model. The launch costs dwarf the panel costs, even when accounting for the lack of weather in space. It just doesn't make sense, especially when you start adding in all of the additional costs like building the satellites, the ground stations, transmission losses, fuel to keep the orbits from decaying, the fact that you won't be able to send these to Geo Orbit without incurring crippling transmission losses, so you'll need a lot of ground stations, etc...
Compared to all of that, the problem of finding parking lots in the suburbs seems absolutely trivial.
Also your design sounds suspiciously like a GDI Ion Canon from Command and Conquer[0]. Imagine having dual-use concerns like we do with nuclear power.
No matter what kinds of launch cost improvements you predict (including, of course, Starship-likes), it will always be orders of magnitude cheaper to just build an array here on earth that is 3-4x larger than to lob anything into orbit.
The Microwave/Laser power transmission schemes of orbital solar are also a huge problem, and in all likelihood would never make it through any kind of environmental impact study, much less an engineering effectiveness/reliability review. (Not to mention that, like the famous laser drive in Larry Niven's Man-Kzin wars, any laser/maser/microwave array that large is inherently a formidable weapon of mass destruction, with no modification other than repointing it....)
Technology moves on, but old wet-blanket excuses live forever.