PG&E wants to put solar cells above the clouds, where they don't need to worry about anything blocking their view of the sun.
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Solar power captured in space, beamed to Earth
By Chris Gaylord | 04.14.09
West Coast energy giant PG&E unveiled a plan this week to put solar panels in orbit and wirelessly beam energy down to Earth by 2016.
Satellite solar cells would capture the sun’s rays 24 hours a day, without fear of cloudy mornings or dark nights. The orbiters then convert this solar power to radio-frequencies that transmit to ground stations in Fresno County, Calif. Once received, the radio energy would change into electricity and flow into the grid.
Such a plan has been accepted by scientists for years. A 2007 Pentagon study concluded that satellite-solar power was feasible, yet significantly more expensive than current energy sources. But PG&E and partner Solaren, a California start-up, claim that their costs will be comparable to rates for other lines of renewable power. They would not give specifics.
“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,” Solaren CEO Gary Spirnak said in an interview published by PG&E. “For over 45 years, satellites have collected solar energy in Earth orbit via solar cells, and converted it to radio-frequency energy for transmissions to Earth-receive stations.”
The power company now turns to state regulators for approval on the 15-year deal with Solaren. Once up and running, the system should produce 800 gigawatt-hours of electricity in the first year, “and 1,700 gigawatt-hours for subsequent years,” reports MSNBC. “The larger figure is roughly equal to the annual consumption of 250,000 average homes.”
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2. tyler | 04.14.09
if the first year only produces 800 gigawatts how many homes will that work for? What is the usage average of a home a month? and if this does work, will you have to buy anything special for your house to pick up these waves since you say its lke a radio station so wold we have to get an antenna to pick up this electricity?
3. Science student | 04.14.09
This seems to defy common sense. Assuming the energy captured and transmitted via this ‘beam’ would have to be very concentrated, enough to incinerate anything it hit - so the risks would be enormous. Compared to existing ground based schemes in deserts that have plenty of available space - these do work and only need to have a national electric grid to connect to.
What could be the motivation to spend money that way? Sounds like a dubious scheme much like the current past miraculous “profits” the financial wizards were feted about just a few years ago.
I can’t believe your editors are serious: “For over 45 years, satellites have collected solar energy in Earth orbit via solar cells, and converted it to radio-frequency energy for transmissions to Earth-receive stations.” These power stations were generating power for their transmissions, sure - BUT they were not transmitting POWER, they were transmitting signals. This is a huge difference. Same huge difference as the power used by the phone lines and the powerlines used by city utilities.
4. Engr. Ishrat Farooqi - PAKISTAN. | 04.15.09
To put solar Panels in Orbit & transmit Stored Solar energy into Radio waves, to earth station & converting them into Electriciry, is really amazing & Interesting.
When Ist Such Solar Power Plant, will be operative & where & of what capacity & size.
What will be the Total Project Cost for 1.0 GW Power.
How much time & how long it will take, to complete & to generate Electricity.
How much space / land on earth / globe, will be required, for a Solar Power Plant of 1.0 GW.
Give details of equipment require for this Solar Plant.
What are the merits & demerits of this technology.
We are involved in SRS Solar Power Plants & would like to invest in this Joint Venture Power Project, for PAKISTAN.
Kindly reply & send technical details & system’s information, with video.
Best Regards.
Engr. Ishrat Farooqi.
PAKISTAN.
5. djr | 04.15.09
I can’t believe that this makes sense - that there’s an ROI. You have to fab, lift, convert - at least 3 times. With 20-something percent efficiency at that panel, probably < 80 percent on the RF transmitter, another 80 at the receiver, losses over the air and mere fab losses; this seems like a fantasy.
6. Oliver | 04.15.09
They keep saying the problem with global warming is the sun that is not reflected back into space anymore because the smaller ice is not doing its job as well as it used to being.
Why not take the solar energy from the ground and reflect the sun back at the same time just like ice would do?
7. Jimbo | 04.15.09
32 yrs ago, this concept was introduced to the general public by various futurists, and the L5 society, only to languish in the dustbin of dead notions. Since then, the efficiency of solar cells has skyrocketed, and eventually the payload cost will come down, allowing the scaling of such solar panel arrays to huge structures capable of powering large metro areas.
It is a delight for me, as one of its aging supporters, to see this idea finally get off the ground and into orbit where it belongs.
Sadly, it took the desperation induced by a faltering economy, global warming, escalating energy demands, & the scary dependence upon foreign oil to make it happen.
Conspicuously missing for decades, was a Kennedy-esque leader, who would spearhead the project and make the dream a reality. President Obama & DOE secretary Chu should champion this project as our only viable alternative to a return to nuclear fission power, a deadly, unworkable monstrosity hovering in the wings of today’s energy policy, one which was wisely and resoundingly rejected 25 yrs ago by the American people.
8. Jimbo | 04.15.09
In retrospect, most of the prior posts are, as Spiro Agnew infamously said, “Nattering Nabobs of Negativism”. Nay-sayers go nowhere, and have their eyes perpetually on the ground.
It was just this sort of hand-wringing & nit-picking, which has relegated this project to SciFi for too long.
We need a CAN-DO attitude.
Oh, & Joe:
The power density is so low it is biologically benign and not even an issue, thereby rendering worries over pointing stability moot.
Our future has & always will lie in space. Not for a tiny percentage of astronauts, but for masses of people eager for the dream & challenge of living on an O’Neill colony, covered with solar cells.
9. PA | 04.15.09
Panel efficiency doesn’t matter as much in space if you have cheap enough square footage…which in space isn’t as constrained as on the ground. Nobody will be whining about disturbing desert ecosystems in space.
11. Jason | 04.15.09
PG&E is required to meet a growing percentage of its load with renewable resources, but can get a pass if a contractor fails to deliver. That “pass” essentially requires that the Public Utilities Commission thought that the contract was a good idea in the first place. In this case, there is a very slim chance that an undercapitalized and inexperienced contractor will solve all of the daunting technical challenges and implement a massive system at a cost per delivered kilowatthour that is remotely competitive with existing solar facilities. I applaud PG&E for considering this novel technology, but I hope that the Commission does not allow PG&E to defer its obligation go green in the likely event that no space-solar system gets deployed.
13. suki | 04.15.09
It’s interesting and I am old enough to remember the speculation from the 1960s that we would be doing something like this.
I have to wonder whether the cost of setting up banks of solar panels on uninhabited desert land on earth wouldn’t be more cost effective than launching and maintaining banks of collectors in space. Doesn’t have the mystique, but seems more practical other than having to negotiate leases for the use of the land for that purpose.
14. JACKW | 04.15.09
TYLER:
THE POWERSATELLITE WOULD BE GEOSYNCHRONOUS. ORBITING HIGH ENOUGH THAT IT APPEARS STATIONARY OVER A FIXED POINT.
THE ENERGY IS BEAMED TO A RECEIVING STATION ON EARTH WHERE IT IS CONVERTED BACK INTO ELECTRICITY. LASER AIMING WOULD CONTROL THE BEAM TO ENSURE NO LEAKAGE BEYOND THE RECEIVER. YOU WOULD NEED NO SPECIAL EQUIPMENT ON YOUR HOME AS ELECTRICITY WOULD ARRIVE AS IT NOW DOES. AS FOR BEING A DEATHRAY…IT’S MY UNDERSTANDING THAT THE ENERGY WOULD BE LOW LEVEL ENOUGH THAT YOU COULD ACTUALLY STAND FOR SEVERAL MINUTES IN THE RECEIVING AREA (ALTHOUGH NOT RECOMMENDED) AND NOT BE HARMED. IT’S NOT A DEATHSTAR LASER…NOR WOULD IT
EVEN BE VISIBLE.
IT IS ABOUT THE CLEANEST ALTERNATIVE THERE IS…AND COULD BEAM ENERGY 24/7/365 AND WOULD ONLY SUFFER A MINOR DROP OFF DURING CLOUDY WEATHER.
15. dottie | 04.15.09
Sounds like a positive development to counter all the negative wrongs trying to be established on the whole earth
16. Sam | 04.15.09
There could be no better investment in America than to invest in America becoming energy independent! We need to utilize everything in out power to reduce our dependence on foreign oil including using our own natural resources. Create cheap clean energy, new badly needed green jobs and reduce our dependence on foreign oil.The high cost of fuel this past year seriously damaged our economy and society. The cost of fuel effects every facet of consumer goods from production to shipping costs. It costs the equivalent of 60 cents per gallon to charge and drive an electric car. If all gasoline cars, trucks, and SUV’s instead had plug-in electric drive trains the amount of electricity needed to replace gasoline is about equal to the estimated wind energy potential of the state of North Dakota.We have so much available to us such as wind and solar. Let’s spend some of those bail out billions and get busy harnessing this energy. Create cheap clean energy, badly needed new jobs and reduce our dependence on foreign oil. What a win-win situation that would be for our nation at large! There is a really good new book out by Jeff Wilson called The Manhattan Project of 2009 Energy Independence Now. http://www.themanhattanprojectof2009.com
17. Jeff | 04.15.09
Wouldn’t the laser not be able to transmit/control the beam in cloudy weather, negating that advantage? It’s nice that the panels could collect it, but if they can’t transmit, there is not benefit.
18. Dan | 04.15.09
@JaxkW & Tyler
They are proposing to beam to specific ground stations and not directly to homes according to article. You would get your power over wires from the electric co.
@Jimbo
No, we need a common sense attitude and not more throwing money at every idea that sounds cool at first glance. “A fool and his money are soon parted.” I would rather focus on functioning solutions rather than pie-in-the-sky ideas that have obvious financial and technical problems. I love space exploration and technology, but I’d rather focus on things that have a good chance of working.
19. dail melton | 04.15.09
Tesla, wanted to do something simalar with alternating current. Huge radio towers that could ‘beam’ the current to homes for free. That method was considered to dangerous at that time too.
20. Elizabeth | 04.15.09
Others have noted that this project is unlikely to be a net energy producer. In addition, the project will shadow the earth robbing someone else of their solar energy. If there were lots of these arrays, lots of crop land wouldn’t grow and lots of earth-based solar energy systems would be shadowed.
21. arfnotz | 04.15.09
An 80% efficient microwave tube is pretty racy, and if the satellite is at 23000 miles you have 23,000 miles of spreading loss. It’s hard to imagine awhat sort of antenna they will use to keep the spot size on the ground under a 100 square miles.
Both the suggestion of solar panels in the desert and “this only has to seem like a good idea” have more merit than this notion of micorwave power from space.
Never mind the high demand for synchonous orbital slots and the $10k per pound launch cost, this is not a particlulity attractive idea from either engineering o finacila consideration. therefore, it must be either a sales gimmick, or a publicity stunt.
22. Robert M. | 04.15.09
Here is some food for thought. So we master the technology and build this big solar voltaic panel in space and beam the energy to Earth as microwaves. The energy is converted to electricity and distributed through the grid. But, then what happens to it?
We know that energy can neither be created nor destroyed. It can only be changed in potential. The electricity we use becomes another form, mostly heat, magnetism and some light. So, what we would actually be doing is gathering up energy that never would have come to Earth at all, then using it for our needs and dumping it into the environment in addition to the warming we already have. It’s not the same as using ground based arrays to capture solar energy that would strike the earth and warm the atmosphere anyway. Would actually be better off or would we be adding to global warming?
Large corporations are going to tell people what they want to hear and likely do otherwise. The best investment is still that of becoming more efficient users of energy.
23. Kewlbob1 | 04.16.09
What would happen in the event of a Electro Magnetic Pulse from a nuclear weapon explosion in space? I assume that the panel array would be destroyed or melted, then you have another piece of space hardware that needs to be jettisoned back to earth to burn up. Also, if our energy grid is dependent upon these space solar panels, then we would have an immediate, unfixable, loss of power supply. Let’s come back down to earth and investigate the tides, natural steam created by the earth, solar concentration of rays into a converter box, and captured movement energy.
I am probably too old to see the solutions that our new generation comes up with, but I am confident that solutions will be found. Just keep government out of it!
24. GaryK | 04.16.09
I know there’s a lot more solar energy at geostationary orbit, about 6 times as much (with no clouds, no dust on the cells to speak of, and because the Earth’s shadow will miss it most of the time, only a few hours of ‘night’ per month) but the $10K/pound just to LEO, and the fuel and whatever to get the structure way out to geostationary after that, make this seem unlikely to be economically profitable.
@Elizabeth, there’d be no shadow. It’d be in an orbit far higher than that of the International Space Station. You wouldn’t even be able to see it in the daytime sky.
@RobertM, yes there would be waste heat, but little carbon footprint from these, so once in operation it’d be a net benefit versus global warming. Whether there’d be a net energy output from the system at all, after subtracting manufacturing, launching, etc., I have no idea.
25. Lifburgh | 04.16.09
Silly questions: If the solar power is being beamed to a receiver, I’m afraid it will be easy for any hacker to “steal” power. Just point your antenna, grab the beam and get the power at no cost… So I guess that the provider (the power company I mean) should find a way to “encrypt” their radio signal to the legitimate receivers…
Will tomorrow’s hackers steal energy, too, not just files? 
26. Matthew home | 04.17.09
If a solar-powered satellite is feasible as perceived by scientists, then it’s a good innovation and energy saving technology. Just hope this plan will work out.
Trackbacks/Pingbacks
1. Solar power captured in space, beamed to Earth (The Christian Science Monitor) | Matt Goes Green | 04.14.09
3. SF Chronicle: For stories on space power, wave power, etc — who you gonna call? | Science News | 04.15.09
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1. Joe Weinstein | 04.14.09
Many informed older readers will be surprised that that this article and its linked sources make no mention of the well-known and (in its day, circa 1962?) much touted seminal study and proposal by Arthur D. Little Engineers. ADL advocated precisely this space-solar-power-beam approach, in the large, to provide copious clean affordable usably concentrated energy to our planet.
The ADL study came during an era focused on space research and potential benefits of space-based technology, and so received considerable fanfare and scientific and sci-fi attention, especially by ‘hard sci-fi’ writers like Arthur Clarke and Willy Ley.
Critiques of the ADL study worried mainly about proper control of the aim of the concentrated energy beams to the earth receiving stations (in PGE’s case near Fresno). Allegedly the beams could become potent ‘death rays’ - whether from lack of due control or from deliberate commandeering by enemy states or terrorists. I’m surprised that this understandable worry isn’t prominently (or even at all) addressed in the article.
On the other hand, proponents can rightly argue that due experience with prototypes, like PGE’s effort, could be very valuable. It might enable a global-scale space-solar-power-beam approach to energy supply which is extremely attractive in regards not only security but also economics and environmental impact.