Off-world Power Generation: Difference between revisions

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=== Concept ===
=== Concept ===


Given:
==== Premise ====
* earth to moon: 238,900 miles
* there are [https://map.gsfc.nasa.gov/mission/observatory_l2.html four lagrange points] that provide constant sun exposure at predictable locations
* l1 to earth/moon: 1 million miles
* the sun primarily produces visible light (not microwaves or gamma...)
* laser transmission is more efficient than microwave, except where earth's atmosphere interferes
* [https://en.wikipedia.org/wiki/Space-based_solar_power current status]: A Gigawatt-range microwave system would weigh ~80,000 tons (prohibitively expensive) [https://www.energy.gov/articles/space-based-solar-power more] [https://e-reports-ext.llnl.gov/pdf/372187.pdf lots more]
* [https://en.wikipedia.org/wiki/Solar_cell_efficiency Solar cell efficiency]
 
Premises:
   
   
<Earth> <-microwave-- <Earth-orbit satellite> <-laser-- <Earth's moon> <-laser-- <L1 solar array>
<Earth>   <-clearsky-burst-laser--   <Earth-orbit satellite>
<Earth> <-clearsky-burst-laser-- <Earth's moon> <-laser-- <L1 solar array>
<Earth> <-clearsky-burst-laser-- <L1 solar array>
 
* <Earth> <- <Earth-orbit satellite>
Laser transmit antenna in space: 1 meter diameter per GW
Receive: Several hundred meters across
 
* <Earth-orbit satellite> <- <Earth's moon>


* <Earth's moon> <- <Earth-Sol Lagrange-point solar array>
==== Goal ====


Targeting the energy requirement of NYC:
Near-Earth solar array about the size of Nebraska to power the globe.
* Power is measured in Newton-meters per second or Joules per second or Watts.
* ~3000 trillion BTU in 2016 = 3000 trillion btu / 365 days = 3.4E+11 btu/hr = 1.0036680479e+11 watts = 100 GW


PV energy collection
Calculations:
* Energy requirement of NYC: ~3000 trillion BTU in 2016 = 3000 trillion btu / 365 days = 3.4E+11 btu/hr = 1.0036680479e+11 watts = 100 GW
* [https://en.wikipedia.org/wiki/List_of_photovoltaic_power_stations PV power stations] collect more power than [https://en.wikipedia.org/wiki/List_of_solar_thermal_power_stations solar thermal power stations].  They seem to average ~3 MW/km^2 (throwing out 2 ridiculous outliers).
* [https://en.wikipedia.org/wiki/List_of_photovoltaic_power_stations PV power stations] collect more power than [https://en.wikipedia.org/wiki/List_of_solar_thermal_power_stations solar thermal power stations].  They seem to average ~3 MW/km^2 (throwing out 2 ridiculous outliers).
* Traditional single-junction cells have a maximum theoretical efficiency of 33.16% [https://en.wikipedia.org/wiki/Solar_cell_efficiency more].  In reality it is around [https://www.solarpowerrocks.com/solar-basics/how-much-electricity-does-a-solar-panel-produce/#top10 18.7%].
* Traditional single-junction cells have a maximum theoretical efficiency of 33.16% [https://en.wikipedia.org/wiki/Solar_cell_efficiency more].  In reality it is around [https://www.solarpowerrocks.com/solar-basics/how-much-electricity-does-a-solar-panel-produce/#top10 18.7%].
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* Approximate energy absorbable by a solar panel in space: 320W / 1.64m^2 / .48% = 400W/m^2 in space
* Approximate energy absorbable by a solar panel in space: 320W / 1.64m^2 / .48% = 400W/m^2 in space
* Approximate required size of a solar array "near Earth" (including l1) to power NYC: 100GW / 400W/m^s = 250 sq km
* Approximate required size of a solar array "near Earth" (including l1) to power NYC: 100GW / 400W/m^s = 250 sq km
* Dan: 1 out of every 811 humans on earth live in NYC, so 250 sq km dish * 811 (assuming every human uses as much energy as a New Yorker) requires a solar array of only around 200,000 sq km - the size of Nebraska - to power the globe.
* 1 out of every 811 humans on earth live in NYC, so 250 sq km dish * 811 (assuming every human uses as much energy as a New Yorker) requires a solar array of only around 200,000 sq km - the size of Nebraska - to power the globe.  A physicist confirms on the back of an envelope that the area needed [https://youtu.be/E0W1ZZYIV8o will be "near-(UK)-country-sized"].


=== Conclusion ===
==== Conclusion ====


Keep it as simple as possible, but no less.
Keep it as simple as possible, but no less.
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=== [[Off-world Power Generation Crowdfunding|Crowdfunding]] ===
=== [[Off-world Power Generation Crowdfunding|Crowdfunding]] ===
=== [[Off-world Power Generation Patrons|Patrons]] ===

Revision as of 00:45, 17 January 2019

Concept

Premise

<Earth> <-clearsky-burst-laser-- <Earth-orbit satellite>

Goal

Near-Earth solar array about the size of Nebraska to power the globe.

Calculations:

  • Energy requirement of NYC: ~3000 trillion BTU in 2016 = 3000 trillion btu / 365 days = 3.4E+11 btu/hr = 1.0036680479e+11 watts = 100 GW
  • PV power stations collect more power than solar thermal power stations. They seem to average ~3 MW/km^2 (throwing out 2 ridiculous outliers).
  • Traditional single-junction cells have a maximum theoretical efficiency of 33.16% more. In reality it is around 18.7%.
  • A 65"x39" (1.64 m^2) solar panel made in 2018 produces ~320W.
  • About 48% of solar energy hitting the Earth reaches the surface. Perhaps optimistic, but we will divide by .48 to get energy-in-space vs on-earth.
  • Approximate energy absorbable by a solar panel in space: 320W / 1.64m^2 / .48% = 400W/m^2 in space
  • Approximate required size of a solar array "near Earth" (including l1) to power NYC: 100GW / 400W/m^s = 250 sq km
  • 1 out of every 811 humans on earth live in NYC, so 250 sq km dish * 811 (assuming every human uses as much energy as a New Yorker) requires a solar array of only around 200,000 sq km - the size of Nebraska - to power the globe. A physicist confirms on the back of an envelope that the area needed will be "near-(UK)-country-sized".

Conclusion

Keep it as simple as possible, but no less.

  • We need to optimize free space power transmission in lab conditions using currently-available consumer electronics.
  • We need to create a solar panel array with robotics that can self-assemble.
  • We need robotics that can precisely and safely aim laser energy to a distant target using a real-time handshaking protocol.
  • We need to determine the cheapest possible way to launch a payload from Earth and navigate it to a final stable destination (lagrange or Earth orbit).
  • We need to determine the requirements to receive laser power at an Earth-based power plant.
  • We need to crowdfund the project.

Research

Prototyping

Crowdfunding

Patrons