California Wants to Draw Energy From the World's First Orbiting Solar Farm

By Eliza Strickland | April 14, 2009 8:47 am

space solarBy 2016, the energy powering some California homes may come from solar panels orbiting the planet. California’s largest electric utility has announced plans to purchase energy from Solaren Corp., a startup company that hopes to launch the first commercial test of space solar power. Solaren would generate the power using solar panels in Earth orbit and convert it to radio-frequency transmissions that would be beamed down to a receiving station in Fresno…. From there, the energy would be converted into electricity and fed into [the] power grid [MSNBC].

The idea of space-based solar energy has been discussed for decades. It appeared in science fiction as far back as 1941 and later received serious study by NASA and the Pentagon. At times, it has been dismissed as fantasy [San Francisco Chronicle]. But the potential of a solar farm that can generate energy day and night, regardless of the weather, has been enticing enough to keep researchers working on the idea. Now, Solaren CEO Gary Spirnak says the technology is ready for prime time. “While a system of this scale and exact configuration has not been built, the underlying technology is very mature and is based on communications satellite technology,” he said [MSNBC].

The electric utility, Pacific Gas and Electric, has asked state regulators to approve the purchase of up to 200 megawatts of solar power from Solaren once their satellite system is built–that’s enough electricity to power about 150,000 homes. “Emerging technologies like space solar face considerable hurdles,” the utility acknowledged in a filing with the California Public Utilities Commission on Friday. However, it added, “PG&E believes that potential, significant benefits to its customers from a successful space solar installation outweigh the challenges associated with a new and unproven technology” [Mercury News].

Solaren says it’s committed to beginning its commercial operation by 2016, but to reach that ambitious goal Spirnak admitted that the company will need to raise billions of dollars. However, he believes his company is up to the task. Solaren’s team of satellite engineers, most of whom worked for the Air Force or Boeing’s space division, will start designing the solar arrays and satellite, working in concert with contractors in the aerospace industry, Spirnak said. The team will perform test launches to try out their designs before moving to the pilot stage, he said [The Wall Street Joural]. The company’s proposed system would require four rocket launches to get the components into space, but once there the parts could be automatically assembled without an astronaut’s assistance.

As for the danger of microwave beams from space going astray and burning up the countryside, PG&E referred to a NASA scientist’s paper [pdf] that made the point that such a space beam carries less energy than sunlight, or about 3 percent of the energy of a typical microwave oven — not enough to boil anyone’s blood [Greentech Media].

Related Content:
80beats: Experiment Is First Step Toward Solar Power Beamed From Satellites

Image: NASA / Pat Rawlings

CATEGORIZED UNDER: Environment, Space, Technology
  • Robert


  • Jo

    Orbiting solar farm? Or … DEATH RAY!

  • Eliza Strickland

    Augh, what a typo. Thanks for the catch, Robert.

  • johnn costello

    beam me down sooty

  • jiriz

    Let’s see: some of the solar energy hitting the panels would otherwise end up being reflected back into space by stratospheric particles and by clouds. Additional energy absobed by the panels would miss the Earth altogether.
    Ergo, the solar farm will be a net contributor to global warming. Way to go, Schwarzenegger! Luckily uncle Al will be able to sell you some carbon credits.

  • John Ahlstrom

    From the URL:

    Dr James Logan, NASA
    Feb 2009

    2.45 or 5.8 GHz 1 to 5 GW non-ionizing power.
    (non-ionizing means not enough energy to ionize atoms or molecules)

    Occupational limit 5mW/cm**2 General limit 1mW/cm**2

    Beam size
    Approx 2-4km wide.

    Beam energy
    Center 300 watt/m**2 or 30milliwatts/cm**2
    (JKA: compare to 5milliwatts/cm**2 above)

    Safety considerations
    Except for maintenance personnel, human exposure
    would not normally be permitted in these areas.
    (JKA:But see size of beam above – 2-4km wide)
    What about terrestrial animals – birds and bees he discusses.
    How many cubic feet of concrete and how many armed guards are necessary
    to “not permit” human exposure?)

    Microwave oven leak energy
    1-5milliwats/cm**2 5 cm from any oven surface

  • M

    jiriz: its radio frequencies that are being beamed down, not light.

  • M
  • David Colton

    1) Microwaves are radio waves. Clouds are largely invisible to them.

    2) An array of large receiving dishes will easily capture the energy.

    3) Security wouldn’t need to be any greater than any other industrial property. Actually less because nothing much will be worth stealing around them. .

    4) The intensity of the microwave beams will be no greater than what is found on any mountaintop or building with microwave relay stations, and considerably less than is found in home microwave ovens. I’ve not heard of birds or insects getting cooked by open air microwave stations. The dishes will probably pose much less of a collision risk than tall buildings, towers, or bridges.

    5) All construction requires concrete and security.

    6) We wouldn’t need all this if the earth held a reasonable and sustainable 500,000,000 or less total population. Now, with our over 6,000,000,000 population, it will take all the ingenuity, industry, and infrustructure we can muster to avoid an ecological collapse and a population collapse. The USA would be affected as much as any other country. Millions of us would die violently and miserably in our cities if the power grid goes down, water transport over long distances stops, and food is no longer shipped in. For survival and the continuance of our civilization, we need all the clean electricity we can get.

  • Stefan

    Excellent comment,
    That’s what I love about this site there’s always at least one informed opinion to counter ignorant posts.

  • Grant H

    Well, this certainly beats burning coal. I hope China take a liking to this idea, I reckon they’ve got the resources and funds to develop the tech and start making serious use of it.

  • Nick

    Radio frequencies are light. Please see Wikipedia for a refresher on the electromagnetic spectrum. They’re just not a part of the so-called ‘visible’ light that we detect with our eyes. That being said, ionizing radiation is on the opposide side of the electromagnetic spectrum (with visible as the median) as compared to radio frequencies.

    Honestly, there’s no magic bullet solution to this problem (power). A combination of things (small scale local wind/solar), treadmills and exerbikes that produce instead of consume energy (what a ridiculous idea, paying for a treadmill, and then paying for power to walk on it when it’s free to walk out the front door – at the very least make them self-powered), piezoelectric floors (and maybe even piezo wands that pull energy out of the wind), keyboards and mice (ever play a frustrating video game on your computer? you’ll get plenty of energy back out of that – especially if you’re a keyboard fist-slammer) and more efficient energy storage devices will be the only solutions.

  • jiriz

    What is there in my post not to understand?

    The solar farm will capture a lot of the sun energy (perhaps as much as 50%) that would normally NOT reach the Earth surface. That energy gets beamed to the surface and converted to heat.

  • veekie

    Do it and have double duty as a solar shade then.

  • Mark D

    Because you see the word “microwave” do you assume it’s heat? You are forgetting the other way microwaves work… it’s very easy to convert it into electrical energy (just like putting a fork or tin foil into your home microwave makes sparks. No, don’t do this.)

    You can debate cost efficiency or lifetime of the solar cells, but it’s not debatable that this is a nearly 0% polluting energy source (I’m sure someone somewhere can argue about the rocket fuel or transmission problems)

  • veekie

    Well, there’d definitely be indirect heating effects, and these can be cumulative if the sunlight captured would not have reached Earth normally(but not in a solar shade placement, where sunlight intensity on Earth is diminished by the obstacle).After all, the energy is converted to electricity and then lost as stray heat somewhere down the line. This is a linear warming effect though, not like the multiplicative one of global warming through emissions. In the short term, this should result in overall cooling until we get warming under control. Plus, the land it’d have otherwise used up on Earth can be put to other, constructive purposes.

  • Adam

    There won’t be a net heating because the rectenna receiver shades the ground below it more than the power it receives from space. Think about it a bit more.

  • http://TwoSistersArtandSoul Lisette Root

    This concept is very interesting, but we need to get a handle on the growing problem of orbiting space junk first.

  • Steve Wahls

    The earth gets all her energy from the sun. But only what strikes the side facing the sun if we add area in space that would normally allow energy to pass on by then the energy we would send down would increase the energy consumption by that amount and be a net increase in atmospheric temp. This method would be a more direct increase in global temp than any other method. Worst choice so far. jiriz is net right. Electricity gets turned into heat when we use it even when we use it to freeze a burger.

  • black nightstand furniture

    It has been really interesting but how will i bookmark this kind of?


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