3 ms·

Or, we could hire children to pedal stationary bicycles attached to generators. Where cost doesn't matter, everything gets easy.

by ncmncm 4y ago

JoeAltmaier 4y ago
Real estate near major metropolitan centers is not cheap either. With modern orbital delivery dropping by orders of magnitude, the entire equation changes. Get with the modern agenda! 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.
- ncmncm 4y ago
  Real estate already generating revenue that may have solar added without reducing that revenue is not expensive. It has, instead, negative cost. 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.
  - JoeAltmaier 4y ago
    That's so far a pipe dream, dual-purpose 'negative cost'. Also transmission lines need right-of-way and are not free. 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.
    - ncmncm 4y ago
      Solar flux outside the atmosphere is not, in fact, 9x sea level. You can cook the numbers by keeping the orbital panel square on to the sun, while the ground-mounted panel rotates through the day and overnight. But you don't get to count nighttime twice. 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.
      - JoeAltmaier 4y ago
        I looked it up. 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-transmission-of-solar-energy-from-space/ 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?
        Schroedingersat 4y ago
        > 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.
        JoeAltmaier 4y ago
- adrianN 4y ago
  Electricity can be transmitted quite easily. Many powerplants are in fact a good distance away from metropolitan centers.
- jandrese 4y ago
  The nice thing about solar is that it doesn't have to monopolize the land. If you want to convert a suburban parking lot to a solar farm you don't have to evict the cars, you just have to install them high enough that the cars can park underneath. 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.

Or, we could hire children to pedal stationary bicycles attached to generators. Where cost doesn't matter, everything gets easy.

by ncmncm 4y ago

Or, we could hire children to pedal stationary bicycles attached to generators. Where cost doesn't matter, everything gets easy.

JoeAltmaier 4y ago

Real estate near major metropolitan centers is not cheap either. With modern orbital delivery dropping by orders of magnitude, the entire equation changes. Get with the modern agenda! 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.

ncmncm 4y ago
Real estate already generating revenue that may have solar added without reducing that revenue is not expensive. It has, instead, negative cost. 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.
- JoeAltmaier 4y ago
  That's so far a pipe dream, dual-purpose 'negative cost'. Also transmission lines need right-of-way and are not free. 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.
  - ncmncm 4y ago
    Solar flux outside the atmosphere is not, in fact, 9x sea level. You can cook the numbers by keeping the orbital panel square on to the sun, while the ground-mounted panel rotates through the day and overnight. But you don't get to count nighttime twice. 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.
    - JoeAltmaier 4y ago
      I looked it up. 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-transmission-of-solar-energy-from-space/ 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?
      - Schroedingersat 4y ago
        > 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.
        JoeAltmaier 4y ago
adrianN 4y ago
Electricity can be transmitted quite easily. Many powerplants are in fact a good distance away from metropolitan centers.
jandrese 4y ago
The nice thing about solar is that it doesn't have to monopolize the land. If you want to convert a suburban parking lot to a solar farm you don't have to evict the cars, you just have to install them high enough that the cars can park underneath. 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.