22 April 2009

Will Space-Based Solar Power Finally See the Light of Day?

This is one of the best, most comprehensive articles written on the subject. Kudos to Adam Hadhazy and SCIAM!
Scientific American: Features - April 16, 2009
Will Space-Based Solar Power Finally See the Light of Day?
A satellite that reaps the sun's energy in space and beams it down to Earth for use as electricity may leave the realm of sci-fi and edge closer to reality this week following an energy deal in California
By Adam Hadhazy
Pacific Gas & Electric Co. (PG&E) has long invested in renewable energy sources, including geothermal, wind and solar. Earlier this week, the utility company reached for the stars in announcing the first-ever deal of its kind: The California power utility, says spokesperson Jonathan Marshall, plans to purchase clean energy generated by a satellite beaming solar power from orbit.The agreement between PG&E and Solaren Corp., an eight-year-old company based in Manhattan Beach, Calif., still hinges on state regulatory approval. If the deal gets the green light, Solaren must then privately raise billions of dollars to design, launch and operate a satellite as well as an energy-receiving ground station slated for the Fresno County area, says Cal Boerman, director of energy services for Solaren.The challenges of building this satellite (due to be completed in 2016) and introducing so-called space-based solar power (SBSP) remain formidable. But driven by the urgency of climate change and the lowering costs of solar technology, a growing number of countries and companies believe an energy revolution could be in the offing.Why bother harvesting solar energy directly from space? It is abundant, and "you can get [this] power 24/7," says Marty Hoffert, an emeritus professor of physics at New York University. Sunlight is some five to 10 times stronger in space, and its shine would reach energy-gathering satellites placed into geostationary (fixed) orbits—the realm of many currently deployed communications spacecraft—more than 99 percent of the time.SBSP could, according to energy experts, provide constant, pollution-free power—unlike intermittent wind and cloud cover–sensitive ground-based solar, and without the emissions of fossil fuels or radioactive waste from nuclear power. "[SBSP] is a disruptive technology [in that] it could change the whole energy equation," says Frederick Best, director of the Center for Space Power (CSP) at Texas A&M University in College Station, Tex.The premise (and promise) of SBSP has been considered scientifically feasible since the late 1960s. The basic concept of beaming microwave frequencies to Earth from orbit has already been proved: A fleet of solar-powered communication satellites routinely beam various electromagnetic frequencies to ground receivers, linking cell phone calls or relaying TV signals to rooftop dishes, for example. Converting solar energy beamed from space into electricity in a power grid, however, has not yet been demonstrated.Space Energy, a Switzerland-based SBSP start-up, aims to change that by deploying a prototype orbiter in the next several years, possibly before Solaren's pilot plant reaches orbit. "You can argue the physics [of SBSP] all day, but you'll only know with a prototype," says Peter Sage, a co-founder of Space Energy, started in 2008.Last year, U.S. and Japanese researchers crossed an important SBSP threshold when they wirelessly transmitted microwave energy between two Hawaiian islands about 90 miles (145 kilometers) apart, representing the distance through Earth's atmosphere that a transmission from orbit would have to penetrate, says Frank Little, associate director of the CSP.Many other technologies relevant to SBSP have made "enormous progress" in recent years, says John Mankins, who led the Hawaiian island test as chief operating officer and co-founder of Ashburn, Va.–based Managed Energy Technologies, LLC. A little over a decade ago, the best photovoltaic efficiency, or sunlight conversion into electricity, was 10 percent, Mankins says; now it can reach 40 percent. And satellite technology has also improved: Autonomous computer systems as well as advanced, lightweight building materials have also made leaps and bounds, he says.Despite such progress, and spending some $80 million, SBSP has not gotten past the U.S. government's drawing board so far. A key reason, Little says: NASA does not do energy, and the U.S. Department of Energy (DoE) does not do space.The U.S. Department of Defense, however, has recently shown interest in SBSP. Air Force Colonel M. V. "Coyote" Smith cites high fuel costs, along with risks to personnel when supplying petroleum to U.S. combat theaters and bases. A 2007 Defense report (pdf) from the Pentagon's National Security Space Office (NSSO), viewed the commercial development of SBSP quite favorably, especially as traditional, fossil fuel energy sources get ever scarcer in the years ahead. "We've got to identify sources of safe, clean energy in order to help us prevent energy wars in the future," says Smith, one of the authors of the 2007 report.The NSSO report said it would be in the fed's interest to encourage the commercial development of SBSP, but that the government should not design or operate the eventual orbiting power plants.The previous government work, including a joint NASA and DoE report from the 1970s about SBSP, has left its mark on many current architectural schemes, though. This textbook approach calls for a massive, microwave-beaming satellite several miles wide that would sport multiple enormous solar arrays connected to a central hub [like the artist's conception on the first page of the article]. The craft would be perched in orbit about 22,400 miles (36,050 kilometers) above Earth, or a tenth the distance to the moon. There, the satellite would maintain a geostationary, or fixed, position relative to a point on Earth's surface while its solar panel arrays bask in the constant sunlight.Captured solar energy then gets converted on board the satellite into electromagnetic carrier waves, specifically microwaves, ideally at a frequency of either 2.45 or 5.8 gigahertz (both fall on the spectrum between infrared and FM/AM radio signals) for subsequent beaming back to the ground. At that frequency, the waves pass easily through the atmosphere, although some energy—physicists do not know exactly how much yet—would be lost during the transfer, Smith says.This invisible column of microwave energy, measuring perhaps a mile or two (two to three kilometers) across, would be beamed at an oval-shaped, ground-based rectifying antenna, or a "rectenna," of similar size, and from there the energy would flow into the traditional electrical grid.Despite the clear analogy to a science fiction death ray, scientists believe the diffuse energy beam from above would not pose a health threat to people or wildlife, even at its most intense center."Microwave radiation is nonionizing, just like visible light or radio signals," says Jim Logan, former chief of medical operations at NASA's Johnson Space Center and an expert on aerospace medicine. That means it lacks sufficient energy, like x-rays and gamma rays, to remove an electron from an atom or a molecule to make a charged particle that can damage DNA and biomolecules, he says.Birds passing through the heart of the carrier wave from space might feel some warmth, Logan wrote in a February white paper on SBSP safety for Space Energy, but not at elevated levels. And should the beam stray from its rectenna target, it would be designed to defocus, Logan says, and not "run amok all over the landscape." Sage of Space Energy says: "We won't be frying birds or turning clouds to steam."Space Energy's first operational array, which adheres to the typical SBSP setup just described, would be designed to generate one gigawatt almost continuously, about the same output as a large nuclear plant. Pursuant to a successful prototype experiment in several years, Space Energy expects that investors would pony up the billions estimated to make a full-scale commercial plant a reality.Building segments of the plant's solar arrays on Earth, along with supports and a central transmitter, would take two years or so, says Stephan Tennsel, CEO and co-founder of Space Energy. Some 40 to 60 launches would boost all the components for the first SBSP satellite into a low Earth orbit (LEO) where a combination of automatic panel unfurling ("like an umbrella," Tennsel says) and robots would assemble and integrate them.Dangers and engineering challenges abound, however: Space junk like that which recently threatened the International Space Station, for example, could collide with the skeletal space solar satellite during assembly. And keeping the satellite's huge beam and the distant rectenna reliably synced up also stands as an unsolved technical issue, says CSP's Little.Overall, the how may be much easier to overcome than the how much. "Technically, we're a lot closer to space-based solar power than we are economically," Little says. The biggest obstacle, he says, continues to be launch costs. "Large structures in space are not showstoppers, but the cost of getting up into space is the real hang-up [for SBSP]," CSP's Best says. In Space Energy's business plan, for instance, half of the $250 million allotted for their communication satellite–size prototype goes toward just lofting the approximately 1,760-pound (800-kilogram) craft into orbit.Though Solaren is tight-lipped about what its pilot power plant will look like, a 2005 patent retained by the company indicates that the firm intends to use mirrors—another oft-explored SBSP element—to gather and focus sunlight prior to converting it to microwaves. According to the patent, Solaren also looks to eliminate many of the structural connectors on its craft—that is, some or all of the satellite's components, including the mirrors, power module and microwave emitter could be "free-floating" in space, orbiting in tandem. "The big thing is to get the weight down so the weight costs don't kill you," says Solaren's Boerman.Backers of SBSP hope that the rising commercialization of space—sparked by the allure of space tourism and the economics of cheaper access—will bring down the expense of rocketing into orbit. Some of the best-known entrepreneurial ventures include Richard Branson's Virgin Galactic and Elon Musk's SpaceX, but almost 20 companies are trying their hand at lowering launch overhead. "These organizations could potentially change the picture of launch costs," Best says.Many other obstacles stand in the way of commercially viable SBSP. A crucial regulatory matter: getting clearance from the U.N.'s International Telecommunication Union (ITU) that allocates use of the electromagnetic spectrum. SBSP's ideal microwave frequencies are already used by wireless systems such as Bluetooth, according to Smith. "Even if we could narrow the beam [from space] down and ensure complete signal integrity in the broadcast wave area," the ITU may deem the possible interference from SBSP as too disruptive to some extant technologies, he says.Some think that SBSP efforts should zero in on lasers rather than microwave transmission to avoid this and other confounding issues. "I think an approach using microwaves is doomed," N.Y.U.'s Hoffert says. Given the necessary size of microwave transmitters and their solar arrays, "it's a huge capital investment before you get one kilowatt of power," he adds.A higher efficiency, laser-based approach would require far smaller satellites and transmitters, perhaps requiring just one launch, Hoffert notes. One proposal involves capturing sunlight in space via photovoltaics, converting the energy into a visible or an infrared laser and then beaming this concentrated light onto existing solar panel arrays in the desert around the clock. Weather can disrupt laser transmissions, however, and Hoffert says other technical hurdles remain for both microwave and laser light approaches.The Japan Aerospace Exploration Agency (JAXA) is covering all bases as Scientific American magazine reported last year. JAXA hopes to have a one-gigawatt satellite in geostationary orbit around 2030 that may use either microwaves or lasers to send its energy back home.Yet another school of thought involves placing solar-power generators and microwave transmitters on the surface of the moon, or even using a lunar base to construct the satellites before launching them (with relative ease, due to moon's far weaker gravity) into a geostationary orbit. Many of the raw materials for crafting the satellites could be mined from the moon as well.If these and other far-flung, future missions ever come to pass, their creators may look back on PG&E's faith this week in Solaren as a key moment in the history of SBSP development, Logan predicts. "If [Solaren] is able to deliver this energy, you're talking about the first time space-based resources have ever been imported to Earth," he says. "It's a significant breakthrough in the awareness of the fact that we're not limited to just the resources on the planet."Auspiciousness aside, Solaren has a long road ahead of it in terms of raising capital and constructing the first-of-its-kind SBSP operation. Soothing local fears of death rays from space will also take some finessing, Logan admits.In the end, PG&E has not invested its customers' or shareholders' finances in the deal, says Marshall, the company spokesperson; rather, Solaren is on the hook to deliver the power first. Over 15 years, Solaren has agreed to provide 200 megawatts of electricity almost continuously, enough for a quarter million homes, starting in June 2016. "Even though PG&E took pains to assure the public they were not investing and that it was only a supply contract, it is still a big step," says CSP's Little. "If another energy supply contract is signed in the near future, I expect interest in space solar will really accelerate."

20 April 2009

More on PG&E and Space Solar

from: http://anz.theoildrum.com/node/5314
The benefits of space based solar power
If Solaren (or other companies pursuing similar ambitions, such as Heliosat, Space Energy, Space Island Group, Powersat and the Welsom Space Consortium) can collect solar energy in space and transmit it to earth they will have opened up a significant new energy resource. The sun's energy is almost continuously available to a satellite located in a geosynchronous orbit about the earth (leading promoters of space based solar power schemes to dub it "baseload solar power").
A 2007 study by the Pentagon’s National Security Space Office which included representatives from DOE/NREL, DARPA, Boeing and Lockheed-Martin found that a one-kilometer-wide band of space in earth orbit receives enough solar energy in just one year (approximately 212 terawatt-years) nearly equal to “the amount of energy contained within all known recoverable conventional oil reserves on Earth today” (approximately 250 TW-yrs). The Pentagon study suggested such a system could be tested as early as 2012, with the likely first customer being the US military.
There are a number of key advantages that make space based solar power an interesting alternative to ground-based solar power:
•There is more energy to be collected - the sun is more intense in orbit than on the surface of the Earth
•Space based systems can collect energy almost around the clock
•Ground-based systems suffer from weather phenomena such as clouds, precipitation, and dust - space based system do not (though the increasing amount of junk in orbit poses a similar hazard)
Real estate costs are minimal - the only land that need be acquired is the land for the receiving station.
•Transmission line costs are greatly reduced compared to remote generation facilities if the ground station is located near existing transmission lines
The video below is from the National Space Society, showing what a space based solar plant might look like.
There are 2 primary challenges to making space based solar a reality.
The first is the technological challenge of making a scheme like this work - this is not been so much converting solar energy into radio frequencies (which has been done before, though not on Solaren’s scale) - but in getting a supersized solar array into space and successfully commissioning it.
The second challenge is one of economics - can the cost involved in building a solar power plant in space ever be competitive with ground based concentrating solar thermal, regular solar PV or thin film solar power plants.
Plans for space based solar have traditionally included kilometre long structures of solar arrays connected to satellites, and launching thousands of tons of heavy metal into orbit is exorbitantly expensive.
Solaren's Spirnak says he has a solution - “We want to take the weight out of these systems. We came up with this design concept to break these things into pieces instead of trying to construct many, many kilometers of structures in orbit, which would essentially be unbuildable.”
Instead, his station will consist of two to four components that will float free in space (kept in alignment by software controls and small booster rockets rather than heavy wires, cables and struts). According to Solaren’s patent, an inflatable Mylar mirror a kilometer in diameter will collect and concentrate sunlight on a smaller mirror that will focus the rays on the solar array. By adopting a concentrating solar power approach, a smaller and lighter array can be deployed, reducing the cost of lifting the components of the structure into orbit.
At this point there is little information about cost available for Solaren's proposal, though Grist quotes Spirnak as saying the price tag for the 200-megawatt solar power station for PG&E will be “in the several billion dollar range” and will require 4 or 5 rocket launches.
The concept of space based solar power was first proposed in 1941 by science fiction author Isaac Asimov in his book “Reason,” about a space station that collects solar energy and beams it to Earth.
Wikipedia's article on the topic includes a good timeline of developments in the field, noting that Dr Peter Glaser was granted a US patent in 1973 for his "method of transmitting power over long distances (eg, from an SPS to the Earth's surface) using microwaves from a very large (up to one square kilometer) antenna on the satellite to a much larger one on the ground, now known as a rectenna".
Asimov continued to promote the idea throughout his life, with this talk (part 1, part 2) on "Threats To Humanity", delivered to The Humanist Institute In New York in 1989, in which he described the threats of global warming and fossil fuel depletion, and recommended the solution as space based solar power whose delivery is managed by a federal world government / "stable world order".
Another peak oil observer who has regularly promoted the idea of space based solar power is JD at Peak Oil Debunked, who has looked at the idea of solar power plants based on the moon a number of times (Lunar Solar Power, More on Lunar Solar Power).
Another space based energy panacea, using helium 3 from the moon to fuel fusion reactors, has caused some cynics to mutter that this is just a scheme to funnel large amounts of funds to well connected aerospace companies. I suspect that similar charges will be laid against spaced based solar power plans until the economics of them can be proven to match those of terrestrial renewable energy projects.
The authors of the Pentagon report mentioned earlier noted that space based solar “has the potential to be a disruptive game changer on the battlefield ... [enabling] entirely new force structures and capabilities such as ultra long endurance airborne or terrestrial surveillance or combat systems” - which implies that there might be more than one reason for wanting to deploy space based solar power - like the symbiosis between nuclear weapons development and the nuclear power industry, it may be that space based solar power provides a civilian friendly reason for building 'star wars" type platforms in space.
Cryptogon has some speculation along these lines, and goes on to wonder if this is another possible example of the introduction of technology developed in "black" military projects (there is a section in my "Shockwave Rider" review that talks about the 5000 secret patents registered by the USPTO) into the civilian sector (echoing his speculation about the role of the new GM CEO appointed by the Obama administration).
Another skeptic commenting on the Solaren proposal at Peak Energy wondered cynically if this was a form of greenwashing by PG&E, saying "This is an opportunity for PG&E to get some free green publicity and "demonstrate" their interest in meeting their RPS requirements. When the power doesn't appear in 2016, they can just throw up their hands and say "we tried, not our fault"."
Most skeptics focus purely on the economics though, with the Motley Fool declaring Space-Based Solar? That's Just Silly and Energy & Capital asking "Why would anyone be interested in space-based solar power when commercial utility scale solar technology on the ground today costs 0.3% of its price?" in The Solar Race Will Be Lost in Space.

GeoEngineering CO2 away with SSP

Here is some big thinking by Keith Henson, one of the founders of the L5 Society on how to use Space Solar Power to displace our fossil fuel regime and "decombust" CO2 for in-ground storage:

18 April 2009

Asteroid bound for Earth! Warn your grandchildren

Also See: http://www.topnews.in/earth-may-be-hit-asteroid-160-years-time-2122768
New Scientist
09 February 2009 by David Shiga
AN ASTEROID that had initially been deemed harmless has turned out to have a slim chance of hitting Earth in 160 years. While that might seem a distant threat, there's far less time available to deflect it off course. Asteroid 1999 RQ36 was discovered a decade ago, but it was not consideredparticularly worrisome since it has no chance of striking Earth in the next 100 years - the time frame astronomers routinely use to assess potential threats. Now, new calculations show a 1 in 1400 chance that it will strike Earthbetween 2169 and 2199, according to Andrea Milani of the University of Pisain Italy and colleagues (www.arxiv.org/abs/0901.3631).With an estimated diameter of 560 metres, 1999 RQ36 is more than twice thesize of the better-known asteroid Apophis, which has a 1 in 45,000 chance ofhitting Earth in 2036 (New Scientist, 12 July 2008, p 12). Both are large enough to unleash devastating tsunamis if they were to smash into the ocean. Although 1999 RQ36's potential collision is late in the next century, the window of opportunity to deflect it comes much sooner, prior to a series of close approaches to Earth that the asteroid will make between 2060 and 2080.

Air Force Looking At Space Solar Power

Air Force Looking At Space-Based Solar Power Possibilities, Inside theAir Force, January 30, 2009
The Air Force is looking at space-based power technology as a way toprovide "metropolitan-class" energy for the nation as well as possiblybeaming megawatts of electricity directly to forward-deployed bases,according to the service's chief scientist. The general idea behind thisinitiative is to place large solar arrays or reflectors intogeosynchronous orbit, Air Force Chief Scientist Werner Dahm told Inside the Air Force during a Jan. 26 interview in his Pentagon office. The arrays could generate their own power, while the reflectors could reflect the Sun's light and concentrate it onto smaller arrays or a"heat engine" to generate power. The energy created could then be beamedto the ground by way of microwave transmission. The energy collector onEarth would most likely be placed in the desert, because the receiving suite would have to be roughly 10 kilometers in diameter, according to Dahm. ITAF reported earlier this month that Air Force infrastructure or energy projects originally planned to begin several years down the road could be initiated earlier than expected so that they could be paid forby a government stimulus plan as a way of creating millions of dollarsfor domestic jobs. The "national" solar-based power concept is to place"metropolitan-scale systems" -- or those that produce 25 gigawatts ofpower, more than that which is needed to power New York City -- intospace, Dahm said. These systems would need solar arrays that are 2.5 kilometers by 5 kilometers in area. "They're so large, people tend togiggle, but you have to remind yourself that you're getting down 25 gigawatts of power," he said.

Space-based Solar Power Comes to Light

From: http://www.satellitetoday.com/via/features/Space-based-Solar-Power-Comes-to-Light_29932.html
Space-based Solar Power Comes to Light
March 1, 2009 Via Satellite Richard Kusiolek
The use solar energy is forecasted to soar in the next eight years as the world’s population looks for alternatives to fossil fuels. It is estimated the sun can provide 219 thousand billion kilowatt hours of energy a year for 6.5 billion people, but converting the sun’s energy into a usable form in a cost-effective manner has proven difficult. Can the satellite industry use its experience with solar arrays to forge a new energy market direction?
In 1941, Isaac Asimov published a science fiction short story of a space solar power system orbiting on geostationary orbit that would beam down from space usable electrical energy. While the vision has taken a few practical steps since that time, the satellite industry should play a key role in making this dream of large-scale solar power production a reality. "The solar industry was born out of the space industry," says Ron Pernick, co-founder of the research firm, Clean Edge, a research and consulting firm focusing on clean technology, "It came out of Bell Labs of the very early implementation of solar for the space industry because they had a very definite requirement for space and satellites. In many ways the terrestrial solar industry has the space applications [industry] to thank for really helping solar gestation for up to two and three decades before it was ready for prime time terrestrially.... They feed on each other. It is a virtuous loop. It is important to pay homage to the fact that today’s modern terrestrial solar energy has very much the space industry to thank," Pernick adds.
John Mankins, president of Space Power Association, a private, international organization that promotes space solar power, estimates with today’s technology the project would cost $10 billion and be in place by 2025. "Energy from a solar power satellite would be transmitted in a coherent beam of low-intensity radio or light energy. An individual receiver on the ground might receive anywhere from 200 to 400 megawatts of power, up to 2,000 to 4,000 megawatts of power," he says. According to Mankins, "the development of space solar power must be an international undertaking and the U.S. should definitely play the leadership role in pulling together that effort."
Several U.S. federal agencies — Department of Energy, NASA, Department of Commerce — have reviewed the concept and concluded that it had no flaws and could be built. The U.S. Department of Defense’s National Security Office has been reviewing the concept as a way of providing energy for global troop deployment. The U.S. Energy Policy Act of 2005 saw the largest budget increase for solar research in U.S. history (to $148 million), but that pales in comparison with two other efforts — the California Solar Initiative, a $3.4 billion project signed into law in August 2006, and Google’s plans to install solar systems in what would be the largest solar electricity corporate campus ever built in California. Internationally, Japan’s Mitsubishi Electric is taking a leading technology role in Asia, and Canada and India have expressed interested in such an electrical grid from space. Chinese, Japanese and European space agencies also are funding research-related space solar power energy projects. The satellite industry, using its long history of solar power development, can play a major part in the development of space solar power efforts. The main technologies can be categorized as concentrating solar thermal (CST) or concentrating photovoltaic (CPV). The former concentrates the sun’s energy on a thermal conductor and then uses the heat to move an engine or turbine. The latter concentrates the sun’s energy directly onto high efficiency photovoltaic material to directly create electricity; however, the current technology of harnessing and the storage of the electricity limits CPV’s ability to be dispatchable. CST is dispatchable but the heat increases the cost of operations. CPV has a concentrated system which can be either a reflector or what is called a Fresnel lens. In a CST system, a Stirling or Brayton engine which utilizes a parabolic reflector to reflect solar energy back into the engine uses the heat (up to 1,500 degrees) in creating alternating current electricity. Photovoltaic cells with a tracking system can increase energy output by as much as 35 percent. Pernick says, "Concentrating solar as far as CPV may have more of a technology challenge. There have not been many CPV technology market places. Many companies are still working on proving the concept."
Solar energy satellite antennas make a lot of sense for manufacturers of antenna systems. One of the U.S. leaders in the convergence of the satellite industry and the solar industry is Patriot Antenna Systems, a division of Cobham, which produces more than two million antennas per year. In 2005 Patriot Solar Group began to focus on compatible opportunities for the company’s satellite antenna design and manufacturing core competencies. "Having the two markets; namely, solar and satellite antennas, is very beneficial. I do not know if this is a huge market in terms of the satellite market, but certainly it is for equipment manufacturers," says Jeff Mathie, president of Patriot Solar Group. "It is especially strong for parabolic, tracking and control manufacturers. Frankly, the solar market needs all the technology and capability that satellite industry integrators have. You have to know the same types of things, such as understanding foundations, appreciating tracking, making sure that the wind loads are calculated, and knowing controller systems."
“The solar industry can now give all of those satellite submarkets categories such as antennas, controllers, integrators and installers a new revenue source that is 10 or 20 times higher than the satellite business ever was.”
— Mathie, Patriot Solar Group
"In my opinion, the same type of companies that were doing business in the satellite industry back in the heydays of satellites in the 80s and 90s can now see opportunities in the solar industry," says Mathie. "The solar industry can now give all of those satellite submarkets categories such as antennas, controllers, integrators and installers a new revenue source that is 10 or 20 times higher than the satellite business ever was. Where we think that most of the technology advances are for our existing satellite technology is in CPV and Stirling engines."
If the answer to space solar power depends on hardware in orbit, there are still numerous — but not impossible — challenges that must be solved, says Mike Ryschkewitsch, NASA’s chief engineer. "There are many engineering challenges, but you are not violating any of the laws of physics. So far at least, no one has identified any show stopper that says that it is impossible," he says. "Everything that I looked at says that it ought to be technically feasible to do it, but no one has taken a hard look at the public policy or political issues, and the economics are just not there....You have to solve the problem of a solar array you build and launch in space is always going to cost significantly more than what you would put on the ground because you have to put it on a rocket and it has to last for a very long time having someone service it. Servicing it would have a high overhead."
Another major issue is that the geostationary orbit already is very crowded with communications satellites, Ryschkewitsch says. "Now you have to put these very large structures [and ensure] that you have no possibility of collisions; that you don’t have any interference from the microwave beams with your communication channels. So there are many other challenges that make it exceedingly unlikely that you are ever going to make a solar array and come out ahead. I am not arguing that solar power in space is not a good idea; however, the key is to do an end-to-end analysis to validate solar arrays in space."
Efforts on the ground also are being developed. In Israel, energy startup Zenith Solar is pioneering a "concentrated solar power" method that is up to five times more efficient than standard technology. A joint Israeli-German research team has designed a working prototype, which consists of a 10-square meter dish lined with curved mirrors made from composite materials. The mirrors focus the sun’s radiation onto a 100-square centimeter "generator" that converts light to electricity. "The first generation of our technology should be capable of harnessing about 70 percent of the solar energy that hits the dish to produce electricity and thermal heat," says David Faiman, chief engineer at Zenith Solar. With that type of efficiency, Zenith Solar says the cost of producing energy with its technology is close to that of conventional fuels.
Other sectors also are working on efforts. Within the global telecoms sectors, Ericsson and Nokia Siemens Networks have installed hundreds of base-stations powered by solar power antennas in developing countries and in rural areas within the developed world. Ground-based satellite solar antennas could be easily networked into an electrical grid to provide "free energy from the sun" and result in reducing the dependency on foreign energy sources.
While large-scale solar energy use is still some time off, other uses for solar power based on satellite industry efforts are making their way into the market. In November, Global Satellite USA launched the Voltaic Solar Backpack, a 4-watt solar-powered storage bag that uses high-efficiency solar cells, to generate power in a limited space. It includes a battery pack designed to store and convert the electricity it generated in order to charge PDAs, cameras, cell phones, satellite phones and iPods. One hour of sunlight will power over 3 hours of iPod playtime or 1.5 hours of cell phone talk.
Converting Solar Hope into Energy
The satellite industry’s efforts in the space solar power arena could play a key role in turning around the U.S. economy. The technologies could converge into a durable business model and lead the U.S. economic recovery from a commercial space business potential, generating investment, innovation and sustainable jobs. A "global smart solar power grid" consisting of space-based and terrestrial solar energy systems would encourage countries to start working together instead of in isolation. Solar energy has the edge on all the other renewable energy sources due to the abundance of the sun’s energy and will lead the energy revolution. The key question is: Can the governments fund and coordinate the necessary research to meet the growing demand of clean and inexhaustible solar energy from Space? "Space solar power is possible, but it will take a long time," says Mankins. "If a thoughtful and [adequately funded] space solar power program were started in 2009, then it’s possible that a 100-megawatt pilot plant demonstrator could be operational in geostationary Earth orbit as early as 2017. Five power satellites could supply 2 percent of the energy needs for the United States," he says.
"Our satellite industry already has the knowledge and capabilities to merge into the solar industry," says Mathie. "The big issue is understanding how to integrate the various elements in a solar system. The key concern in the market is: How are you going to integrate a solar system into the world markets? The satellite industry has a large network of integrators."

15 April 2009

Space Solar Power---Money on the Table!

Pacific Gas & Electric is going to great lengths--all the way to space--in its quest for renewable energy.
The California utility on Monday said that it will seek approval from regulators to purchase 200 megawatts worth of solar energy delivered from stealth space solar power company Solaren over 15 years The idea of space-based solar power (SBSP) is to place a device in space that can convert solar energy into a usable form and have it transmitted wirelessly to Earth. Scientists have thought to capture solar energy from space for decades but has it has never been done commercially.
Solaren proposes placing solar panels on a satellite to generate electricity that is converted to radio frequency energy on-board and sent to a ground station in California. The receiver then converts the radio frequency energy to electricity and it is fed into the power grid.
The goal of the project is to provide electricity to PG&E by 2016, said Solaren CEO Gary Spirnak in a Q and A posted on PG&E's company blog.
"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. 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. This is the same energy conversion process Solaren uses for its (space solar power) plant," he said.
PG&E, which has significant investments in different forms of renewable energy, said that there is no risk to the utility since it only pays for power produced.
The advantage of space solar power is that energy can be harnessed at all times, even at night or when it's cloudy. Solaren's contract calls for it to deliver baseload power, the electricity needed to meet customer demand.
In its posting, PG&E executives said that generating space solar power cost effectively is a major challenge, but the people at Solaren have a lot of experience in space and satellites. The field also can also draw on years of research.
Another company called Space Energy has been formed to also tap solar energy from space using a similar technique as Solaren.
PG&E makes deal for space solar power
Utility to buy orbit-generated electricity from Solaren in 2016, at no risk
By Alan Boyle
Science editor
updated 10:41 p.m. ET April 13, 2009
California's biggest energy utility announced a deal Monday to purchase 200 megawatts of electricity from a startup company that plans to beam the power down to Earth from outer space, beginning in 2016.
San Francisco-based Pacific Gas & Electric said it was seeking approval from state regulators for an agreement to purchase power over a 15-year period from Solaren Corp., an 8-year-old company based in Manhattan Beach, Calif. The agreement was first reported in a posting to Next100, a Weblog produced by PG&E.
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, PG&E said. From there, the energy would be converted into electricity and fed into PG&E's power grid.
PG&E is pledging to buy the power at an agreed-upon rate, comparable to the rate specified in other agreements for renewable-energy purchases, company spokesman Jonathan Marshall said. Neither PG&E nor Solaren would say what that rate was, due to the proprietary nature of the agreement. However, Marshall emphasized that PG&E would make no up-front investment in Solaren's venture.
"We've been very careful not to bear risk in this," Marshall told msnbc.com.
Solaren's chief executive officer, Gary Spirnak, said the project would be the first real-world application of space solar power, a technology that has been talked about for decades but never turned into reality.
"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 in a Q&A posted by PG&E. A study drawn up for the Pentagon came to a similar conclusion in 2007. However, that study also said the cost of satellite-beamed power would likely be significantly higher than market rates, at least at first.
In contrast, Spirnak said Solaren's system would be "competitive both in terms of performance and cost with other sources of baseload power generation."
Solaren's director for energy services, Cal Boerman, said he was confident his company would be able to deliver the power starting in mid-2016, as specified in the agreement. "There are huge penalties associated with not performing," he told msnbc.com. He said PG&E would be "our first client" but was not expected to be the only one.
The biggest questions surrounding the deal have to do with whether Solaren has the wherewithal, the expertise and the regulatory support to get a space-based solar power system up and running in seven years. "Quite a few hurdles there to leap," Clark Lindsey of RLV and Space Transport News observed.
In the Q&A, Spirnak said his company currently consists of about 10 engineers and scientists, and plans to employ more than 100 people a year from now. He said each member of the Solaren team had at least 20 years of experience in the aerospace industry, primarily with Hughes Aircraft Co. and the U.S. Air Force. Spirnak himself is a former Air Force spacecraft project engineer with experience at Boeing Satellite Systems as well.
"The impetus for forming Solaren was the convergence of improved high-energy conversion devices, heavy-launch vehicle developments, and a revolutionary Solaren-patented SSP [space solar power] design that is a significant departure from past efforts and makes SSP not only technically but economically viable," Spirnak said.
Boerman said Solaren's plan called for four or five heavy-lift launches that would put the elements of the power-generating facility in orbit. Those elements would dock automatically in space to create the satellite system. Boerman declined to describe the elements in detail but noted that each heavy-lift launch could put 25 tons of payload into orbit.
"We've talked with United Launch Alliance, and gotten an idea of what's involved and what the cost is," he said.
The plan would have to be cleared by the Federal Aviation Administration as well as the Federal Communications Commission and federal and state safety officials, Boerman said.
In the nearer term, PG&E's deal would have to be approved by the California Public Utilities Commission, Marshall said.
He said the space-power agreement was part of PG&E's effort to forge long-term deals for renewable energy, including deals for terrestrial-based solar power. Marshall pointed out that space-based and terrestrial-based solar power generation were "really very different animals."
Unlike ground-based solar arrays, space satellites could generate power 24 hours a day, unaffected by cloudy weather or Earth's day-night cycle. The capacity factor for a ground-based solar is typically less than 25 percent. In contrast, the capacity factor for a power-generating satellite is expected to be 97 percent, Marshall said.
"The potential for generating much larger amounts of power in space for any given area of solar cells makes this a very promising opportunity," Marshall said.
He said the agreement called for 800 gigawatt-hours of electricity to be provided during the first year of operation, and 1,700 gigawatt-hours for subsequent years. The larger figure is roughly equal to the annual consumption of 250,000 average homes.
PG&E has 5.1 million electric customer accounts and 4.2 million natural-gas customer accounts in Northern and Central California.
Space Based Solar Power A Reality By 2016?
by Energy Matters
The idea of harvesting solar power from space via orbiting solar farms has been around for a while, but may be closer to reality than many of us realised.The solar energy available in space is up to ten times greater than on Earth as there's no atmospheric or cloud interference to contend with, no real night and no seasons. This means that if solar power could somehow be harvested from space, it could be a baseload resource instead of an intermittent source of power.Baseload issues are one the last frontiers in terms of many forms of renewable energy and one of the few remaining arguments supporting the need for fossil fuel or nuclear based power.But how do you get the power from the solar panels affixed to orbiting platforms back to Earth? The general concept has been to convert it to radio frequency energy for transmission to a receiving station, which then converts it back into electricity.While this technology may seem decades away, perhaps only possible next century; US company Portland Gas & Electric is seeking approval from regulators for a power purchase agreement with Solaren Corp., a Southern California company that has contracted to deliver 200 megawatts of clean, renewable power from space over a 15 year period, commencing in 2016.Solaren will place solar panels in earth orbit, transmit the energy to a receiving station in Fresno County, which will then be converted to electricity and fed into PG&E's power grid.If successful, the pilot project could address issues such as the use of environmentally sensitive areas for sprawling solar farms. However, one issue that hasn't been addressed is the energy required to produce and put these solar panels into space versus the amount of energy they may generate - and that's where space elevators may come into play.

02 April 2009

How to save the world from an asteroid impact

From: http://www.newscientist.com/article/mg20127015.600-how-to-save-the-world-from-an-asteroid-impact.html?full=true&print=true
25 March 2009 by David Shiga
IT IS 2036. A large asteroid is on a collision course with Earth. Unless it is stopped, it will crash into the Pacific Ocean, creating a devastating tsunami. What should we do?
[2036 would be way too late for any option w/respect to Apophis. Even the last ditch concept discussed below requires you to be in place about 3 years prior to impact, and mission duration to intercept or rendevous might exceed a year.]
We could blast the asteroid with a nuclear bomb, but that would risk shattering it into smaller pieces that could still threaten Earth. Or maybe we should try to force it off course by slamming into it with a heavy object - an unproven and therefore risky technique. Now there may be a third option: gently nudging the asteroid away from Earth without breaking it apart, either by exploding a nuclear device at a distance or zapping it with high-powered lasers.
Astronomers have found thousands of asteroids that pass near Earth's orbit, and a few of these are on trajectories that give them a small chance of hitting Earth. The most worrying is a 270-metre-wide asteroid named Apophis, which has a 1 in 45,000 chance of hitting us in 2036.
To investigate the best way to deflect this and other asteroids onto a harmless path, a team led by David Dearborn of the Lawrence Livermore National Laboratory in California has modelled the impact of a nuclear explosion on an object's trajectory. Their virtual asteroid was 1 kilometre in diameter and made of rocky rubble loosely bound together by gravity, which is considered by many planetary scientists to be the most likely composition for small asteroids.
Thirty years before the asteroid was set to collide with Earth, a nuclear blast, equivalent to 100 kilotonnes of TNT, was set off 250 metres behind it. The nudge from the explosion increased its velocity by 6.5 millimetres per second, a slight change but enough for it to miss us.
The technique also reduced the risk of a break-up - just 1 per cent of the asteroid's material was dislodged by the blast, and of that only about 1 part in a million remained on a collision course with Earth. Dearborn adds that the technology for this method is already established, unlike for the use of a heavy object to shove the asteroid onto a different path - the "kinetic impactor" strategy. "Should an emergency arise, we should know that [the technology] is available, and we should have some idea of how to properly use it," he says.
He has now begun simulating the effect of nudging an asteroid with a smaller nuclear explosion - less than 1 kilotonne - 1 metre below its surface. This would reduce the device's weight, making it easier and quicker to launch. He will discuss the work next month at the 1st IAA Planetary Defense Conference in Granada, Spain.
A less established and gentler approach would be to nudge the asteroid away from Earth using lasers. In this theory, being investigated by Massimiliano Vasile of the University of Glasgow in the UK and colleagues with funding from the European Space Agency, a fleet of eight or more spacecraft, each carrying a laser, would be sent to rendezvous with the asteroid. Hovering a few kilometres away, each craft would unfurl a 20-metre-wide mirror made of a flexible material such as Mylar. The mirror would focus the sun's rays onto the spacecraft's solar panels, powering the laser.
All eight lasers would then be simultaneously fired at a single spot on the asteroid's surface, vaporising that region and creating a plume of gas that should provide enough thrust to push the asteroid off course (see diagram). This relatively gentle nudging, over a period of months or years, would not break the asteroid up into any smaller pieces, the team say.
Vasile, who will also be presenting his idea at the conference, touts the flexibility and reliability of the approach. "You have a formation of satellites and if one breaks you have the others [for back-up]," he says. "And it's scalable, so if you have a bigger asteroid or you want to have a faster deflection then you add more spacecraft."
Whichever option is ultimately chosen, reliability will be essential for a task as critical as asteroid deflection, says Bill Ailor of the Aerospace Corporation in El Segundo, California, who is chairing next month's conference. "Launch vehicles fail at a rate of about 1 in 100, and new spacecraft might fail at the rate of 1 in 3, [which] has to be factored into the overall design of your deflection," he says. "We're in a sense betting the planet that we're going to make this work."
One big bang and the threat has gone
If we find an asteroid on a collision course with Earth, with no time to gently deflect it from its path, should we blow it up? It's a controversial idea as it would break the object into smaller pieces, many of which could still hit Earth. Yet there have been few studies looking into the risk that this would in fact happen.
Now a team led by David Dearborn of the Lawrence Livermore National Laboratory in California have carried out a computer simulation that shows the risk may not be as great as had been feared. In their simulation, a 1-kilometre-diameter asteroid was discovered with little warning time. A spacecraft carrying a 900-kilotonne nuclear device intercepted the asteroid 1000 days before impact, burrowed 10 metres into it and exploded. The blast turned the asteroid into a giant debris cloud, and although some of the debris still hit Earth, it amounted to only 1/100,000th of the asteroid's original mass of 1 billion tonnes.
However, Derek Richardson of the University of Maryland in College Park cautions that trying to disperse an asteroid in this way would be risky, since the effect of the explosion will depend on the object's internal structure. "It may be that you just blow out a big hole on the surface," he says.

Scientists Track Down Fallen Star Treasure

From: http://www.technewsworld.com/story/66630.html
By Seth BorensteinAP 03/26/09 9:07 AM PT
Scientists eager to study an asteroid before its disintegration in Earth's atmosphere got their wish upon a star, so to speak. Through painstaking tracking and a desert search, they were able to recover fragments of a meteorite shot through with nanodiamonds. The discovery sheds light on the formation of planets and may help refine plans for avoiding a catastrophic asteroid strike.
For the first time, scientists matched a meteorite found on Earth with a specific asteroid that became a fireball plunging through the sky. It gives them a glimpse into the past when planets formed and an idea how to avoid a future asteroid Armageddon.
Last October, astronomers tracked a small nonthreatening asteroid heading toward Earth before it became a "shooting star," something they had not done before. It blew up in the sky, and scientists thought there would be no space rocks left to examine.
However, a painstaking search by dozens of students through the remote Sudan desert came up with 8.7 pounds of black jagged rocks, leftovers from the asteroid 2008 TC3. Those dark rocks were full of surprises and minuscule diamonds, according to a study published Thursday in the journal Nature...The asteroid, which mostly burned in the atmosphere 23 miles above the ground, is likely a leftover from chunks of rock that tried and failed to become a planet about 4.5 billion years ago, scientists said...Blowing it up -- as in the Bruce Willis movie "Armageddon" -- wouldn't be smart, because this type of asteroid turns out to be very much like a "traveling sandpile," Zolensky said. [See http://www.newscientist.com/article/mg20127015.600-how-to-save-the-world-from-an-asteroid-impact.html?DCMP=OTC-rss&nsref=online-news for a difference in opinion] "If you blow it up, all the pieces are heading toward Earth."
Instead, a spaceship-aided nudge would be more effective, said NASA Ames Research Center director Simon "Pete" Worden, another study coauthor. He is a longtime advocate of a worldwide program to plan for the threat of asteroids and comets hitting Earth.
"The real important issue is to understand the physics of these objects," Worden said.
There are many different types of asteroids, all classified from afar based on color and light wavelengths. This type is called "class F," and it turns out to be mostly porous and fragile. University of Maryland's McFadden said it's unlikely that a class F asteroid could be any danger to Earth -- even if it were bigger -- because of its porous makeup, which would cause it to break up before hitting.
The fragments of asteroid 2008 TC3 are full of metals, such as iron and nickel, and organics such as graphites, Zolensky said. Most interesting is that it has "nanodiamonds." These diamonds are formed by collisions in space and high pressure, and they are all over the rocks, making them glitter like geodes, he said -- but they aren't big.

Transhumanist Magazine H+ Covers Space Solar Power

Author Howard Bloom (Global Brain, Lucifer Principle) talks about Space Based Solar Power, and "Brining Space to Life by Bringing Life to Space" in Transhumanist Magazine H+
(See Page 43)