Off-world Power Generation Research

Current conclusions

• Use a satellite in low-earth sun-synchronous polar orbit.
• Use lasers for power transmission not microwaves.
• Use batteries for storage not capacitors.
• Use low-power laser handshaking for safety cutoff.
• Use best-practice cyber-security.

Earth orbits and other locations in space

• earth to moon: 238,900 miles
• there are four lagrange points that provide constant sun exposure at predictable locations
• l1 to earth/moon: 1 million miles
• A geosynchronous orbit takes one sidereal day, and is 35,786 km (22,236 mi) above the Earth's surface. Those closer to Earth orbit faster than Earth rotates, so from Earth, they appear to move eastward while those that orbit beyond geosynchronous distances appear to move westward.
• other interesting earth orbits: low goes across poles, medium used by GPS, high is slow and crawls west, Molniya spends more time away from equator; relative distances diagram
• sun-synchronous orbits that "ride the terminator" (the line that separates night and day, aka "dawn/dusk orbit") are low-earth polar orbits that maintain constant solar exposure. They cross many locations on the earth throughout the year - this guy KNOWS ORBITS, lots to learn here - sun-sync video example - scientific satellites that use this orbit include Yohkoh, TRACE, Hinode and PROBA2
• Is there a sun-synchronous orbit that frequently passes over predictable locations on Earth's surface? That would be ideal for our purpose.

These are therefore probably less useful:

• <Earth> <-clearsky-burst-laser-- <L1 solar array>
• <Earth> <-microwave-- <Earth-orbit satellite> <-laser-- <Earth's moon> <-laser-- <L1 solar array>
• <Earth> <-clearsky-burst-laser-- <Earth's moon> <-laser-- <L1 solar array>
• <Earth-orbit satellite> <- <Earth's moon>
• <Earth's moon> <- <Earth-Sol Lagrange-point solar array>

Power 101

• Power is measured in Newton-meters per second or Joules per second or Watts.
• openenergymonitor intro to AC power in the home
• Power electronics Coursera class

Free-space power transfer

• the sun primarily produces visible light (not microwaves or gamma...)
• laser transmission is more efficient than microwave, except where earth's atmosphere interferes
• current status: A Gigawatt-range microwave system would weigh ~80,000 tons (prohibitively expensive) more lots more
• Solar cell efficiency
• Laser transmit antenna in space: 1 meter diameter per GW
• Receive: Several hundred meters across

Working Systems

NASA 2009 Power Beaming Competition

LaserMotive charging an unmanned drone

space elevator, and its power beaming need

• Attempting this challenge requires that the participating teams would excel at laser optics, photovoltaics, electrical and mechanical engineering, and overall system design. The vehicles must be lightweight yet powerful. The laser beams must be well focused while tracking the climbers, and the climbers must be adept at converting them back into electricity and then into mechanical power. If you think this sounds complicated, you're right - out of about 40 teams that tried their hand at the challenge, only 3 made it to the final challenge.

Coupled PV cells and Lasers

Often called Power Over Fiber.

MH GoPower (MHGP) produces a high-performance silicon-based vertical multijunction (VMJ) PV cell that enables high-wattage laser power transmission. See here.

Preliminary test data is shown for a 0.78 cm/sup 2/ VMJ cell with 40 series connected junctions producing 31.8 watts at 25.5 volts at near 2500 suns AM1.5 intensity (40.4 watts per cm/sup 2/ output at 211 watts per cm/sup 2/ input with an estimated efficiency near 20%).

Powerlight has free-space power beaming tech. LaserMotive has previously demonstrated power beaming systems with a receiver-specific power as high as 800 W/kg.

Several vendors

Solar Panels

Why not buy a nice full-sized panel and see what we can collect with it?

330W for $271 ($.78/W)

100W for $115 ($1.15/W) (bought)

Panels and battery setup

Someone used the Renogy panel to charge their RV, "My system consists of the following main components:"

2 - Victron Multiplus 12/3000/120-50
Victron Blue Solar charge controller MPPT 150/85
15 - 100 watt Renogy solar panels
Victron Color control gx
Victron BMV-702 battery monitor
4 - 1000Ah LifePO4 Winston battery cells

Here's 3.3kwhr in a suitcase using "18650"s.

Jehu, my fave instagram electric ride hacker, explains how to build your own powerwall. I need this.

Super capacitors

• Super-capacitors are not ready to outperform batteries, at least not yet.
  • Because existing supercapacitors have poor energy density per kilogramme (currently around one twentieth of existing battery technology), they have been unable to compete with conventional battery energy storage.
  • Even with this restriction, supercapacitor buses are already being used in China, but the current technology means that they need to stop to be recharged frequently (i.e. at almost every bus-stop).
• Demonstration of using a supercapacitor to meet the needs of charging a car, definitely within its ability. Electroboom agrees.

Long-range handshake

• Here is how NASA did it with Voyager (1970-2029!)

Small Lab Research

We should be able to set up two arduinos or pis, one receiving sun solar to power a laser, and another receiving laser solar to power a battery. We have a lot to learn about basic electrical wiring and arduinos and pis.

A hackster laser morse code transmitter and receiver setup, very useful The laser that was used, very popular, didn't find any others yet

There are lots of competing low-quality solar+battery projects, where's the winner? Still looking...

• this does it all, with pi webserver and arduino to monitor power, but doesn't give many details
• expensive adafruit gear
• might be good but where are the docs?
• work-in-progress but describes pulsed on-then-off to save power

General IoT research

• getting power to the stupid arduino
• open source power monitoring software and hardware using pi and arduido
• open source IoT SDK goo shit

Strong lasers:

• Start with goggles, here's why
• 1-3.5W lasers "world's best" but not avail in US - does not seem to be easy to wire up, but perhaps we could crack it open
• 5W laser in lots of videos... but can you still get it anywhere?
• crazy styropyro's 200W "laser bazooka" - this guy is incredible, here's a diagram of him inverting a Galilean telescope to focus a laser - a short documentary - his ruby laser "my strongest ever"
• another ruby laser with detailed explanation
• found one! this guy's 3D printer laser hack is amazing, and linked to his laser part let's get it

Other random stuff:

• 37 mysterious chinese arduino sensors
• Lidar

Launching Payloads to Space

Rocket Lab’s Electron booster launches small satellites commercially

Nasa "Venture Class" contractors circa 2015

General Notes

Question: what's the maximum input into a photovoltaic cell? Exposing it to the sun in space will provide what percentage of peak opportunity? Should we employ mirrors or prisms to redirect more sunlight into the PV cells? what would be most cost effective: adding more PV cells or adding redirected/reflected sunlight to existing PV cells?

Wikipedia: Wireless_power_transfer via laser (aka "Power Beaming")

Wikipedia: Space Based Solar Power (SBSP)

Long Range Wireless Power by Wi-Charge demoed at CES 2018 - First wireless power system using lasers for consumer applications. Complies with mandatory IEC 60825 sagfety standards for consumer use.

OEM looking to incorporate wireless power modules into new products? Apply for beta

NASA Armstrong Fact Sheet: Beamed Laser Power for UAVs

Power by Light - blog with working prototypes

Youtube: Wirelessly Powered Train

Youtube: Photovoltaic laser power converters with increased voltage output (27m)

Academic Papers

U.S. Energy Department’s own Lawrence Livermore National Laboratory (LLNL) 2009 proposal (PDF)

energy.gov with Infographic

laser power beaming light-to-electricity conversion efficiency correlates directly between electricity conversion and heat generation - abstract behind paywall

Development and characterisation of laser powerconverters for optical power transfer applications - French paper 2013

Paper: Design and optimization of GaAs photovoltaic converter for laser power beaming

Paper: Photovoltaic laser power converters for wireless optical power supply of sensor systems

Paper: High-Voltage GaAs Photovoltaic Laser Power Converters

Youtube infotainment

• electronics: jehugarcia, ElectroBOOM, GreatScott!, EEVBlog, bigclivedotcom, Jeremy Fielding, Fran Blanche, The Hacksmith
• lasers: styropyro, Marco Reps
• robotics: Metatronics, Adafruit Industries, simone Giertz (relentlessly pursues creativity with fun robots)
• other: Captain Disillusion (awesome entertaining video 3D graphics), Cody'sLab (chemistry), AvE (mechanical engineering (and electronics?)), PhysicsGirl (physics)
• general: The King of Random, TheBackyardScientist, SmarterEveryDay, Veritasium, Vsauce, Adam Savage’s Tested