The next frontier in space: solar power - By CHRISTOPHER DAVIDSON
We see the news every day.
The nation's worst oil spill is spoiling the Gulf of Mexico. Our natural resources continue to dwindle. Energy costs rise. The depletion of the ozone layer goes on, thanks to our use of chlorofluorocarbons.
But working diligently in labs and startup firms is a small but vocal group of space scientists and engineers in the United States and abroad, hoping to find the solution to the three-headed monster of energy shortages, global warming and environmental disasters. Their prospective answer? It goes by SBSP, short for space-based solar power, and it's electricity from solar energy collected in earth's orbit.
The technology represents a potential long-term fix to our nation's energy dilemmas. Eventually, proponents say, there could be virtually unlimited energy, driving down costs as the local utilities compete with the space-based solar power company to get your business. Pollution will decrease as fewer fossil fuels are burned. Solar power could be more reliable than wind or conventional solar power.
By June 2016 - the year suppliers have committed to bring the project to market - energy from sunlight could be transformed into low-energy density microwaves, travel all the way from orbit at 22,000 miles above the Earth, through the atmosphere and clouds, to receiving antennas on the ground, and from there, get converted back into electricity and fed into the electrical grid.
At least that is what some scientists say.
In the other camp is the group of naysayers, those who say it is unlikely that companies actively pursuing space-based solar power will be able to deliver, given the capital and technical questions.
"There's a new sucker born every day ... and lots of high net-worth investors in the space industry are suckers," said Shubber Ali, a management consultant who worked with the space industry and founded the "Space Cynic" blog.
And there lies the question. Who is right?
SBSP's opponents say it's unbearably expensive, but supporters believe it solves our national energy problems. Is it a no-brainer, a slam dunk, or instead a science-fiction fantasy promoted by snake-oil salesmen?
According to study of SBSP commissioned by the Pentagon and released in 2007, the Department of Energy and NASA invested $80 million between 1971 and 2001 in cutting-edge research and concluded that the SBSP numbers didn't add up. However, the 2007 study also argued that beaming solar power from space could be safe and technically feasible if costs came down. Solar panels have become cheaper since 2007, and if oil goes up in price, SBSP will enter the realm of real possibility. Since the study was released, a few entrepreneurs and investors from around the globe have committed millions of dollars to its development.
Now, a different kind of space race is on to try to capture solar energy from space and introduce it to the commercial market.
In Southern California, Manhattan Beach-based startup Solaren Corp. appears to be out in front in the race to commercialize solar power beamed from space. In April 2009, PG&E, a leading California utility, signed a 15-year agreement with Solaren to supply it with 200 megawatts of space-based solar power, enough to power 200,000 homes, each year beginning on June 1, 2016.
The California Public Utilities Commission approved the contract in December 2009. By May 2010, the California Energy Commission had pre-certified a Solaren power-receiving facility under the state's Renewable Portfolio Standards. Located in Cantus Creek, near Fresno, the facility currently is under construction. It will consist of a four-square-mile array of antennas that capture the microwaves arriving from Solaren's orbiting solar power plant, convert them into electricity, and feed them into the PG&E grid.
This summer, Solaren plans to begin ground testing for its project, now nearly 10 years in the making. The company will launch free-flying arrays of "power satellites" that will generate solar energy as they orbit the Earth, convert it first to electricity and then to microwaves, then transmit the microwaves from Earth's orbit to the Fresno-area facility.
According to Solaren CEO Gary Spirnak, the company plans to outsource virtually all of its manufacturing to U.S. aerospace firms, most with a strong Southern California presence. Spectrolab in Sylmar will supply rugged high-efficiency solar panels, essentially supersized versions of the equipment that currently powers telecommunications satellites used by DirectTV or Dish Network to broadcast television signals around the world. Rockets to launch the panels will be manufactured by, among others, Palmdale's Boeing Corp. and by SpaceX, a Hawthorne-based startup founded by South African-born entrepreneur Elon Musk.
Solaren is still seeking suppliers for the high-efficiency amplifiers that can convert the electricity generated by the panels into microwaves that can be safely transmitted to Earth, but Spirnak has his eye on the work of engineers at UC Santa Barbara. With all the parts in hand, Solaren will assemble the power satellites on Earth, separate them into five batches, and launch each batch into orbit, flying them in formation under the remote guidance of engineers on Earth.
For supporters, the PG&E contract and the regulatory approval from state agencies are evidence that space-based solar power, as envisioned by Solaren, makes economic and technical sense. Researcher and space advocate Al Globus, a member of the board of directors of the National Space Society, said, "The big elements, solar collection and final power transmission, are thin film and weigh very little. The solar collection is done by a [lightweight] mirror. They solved the antenna size problem elegantly _ the transmitter is small and directed at a large mirror, also thin film, so the Earth antenna sees a large thing. Looks hard to do, but I don't see anything impossible."
Solaren's chief competitor is Space Energy, a multinational startup firm with ambitious plans to build solar plants both on Earth and in space. James Michael "Mike" Snead, a technical advisor to Space Energy, addressed the annual International Space Development Conference in Chicago in May and shared some eye-catching statistics about global energy demand.
Assuming current trends, the Earth will need 60 percent more energy in 2100 than we can access today, he said. The fossil fuels that supply the lion's share of today's energy are finite and contribute to global warming, so they will need to be replaced with renewable sources by 2085. Today's renewables supply only 14 percent of America's energy needs. In order to replace fossil fuels and make up the difference between today's energy demand and tomorrow's, we would need to increase sustainable energy sources by 11 times, and set aside 500,000 square miles of land. Solar panels that met all our energy needs would "take up most land in the Southwestern U.S.," Snead said.
If we used wind power, he continued, we would need 266,000 square miles of wind farms at a cost of $14 trillion. Were we to rely on traditional nuclear power, we would have to build 6,000 nuclear plants by 2100. About 800 five-gigawatt SBSP plants could meet all our projected energy needs "without consuming any land on Earth," he said.
That's isn't to say this project would prove inexpensive. While SBSP components have fallen in price, the complete infrastructure necessary to collect and convert space solar to Earth electricity remains immeasurably more expensive and complex to build than standard "terrestrial" renewable energy.
Today it costs $10,000 to launch one pound of equipment just into low-earth orbit, 200 miles above Earth's surface. A full-scale, space-based solar-power plant would require that thousands of tons of solar panels, solid-state amplifiers, mirrors and heat-dissipating radiators be launched to geosynchronous orbit, 22,000 miles above Earth, and then guided and monitored from the ground.
Buried in the conclusions of the 2007 Pentagon study was this statistic: with current technology, SBSP still wouldn't be competitive with other forms of renewable energy because the estimated launch costs for a fully built-out SBSP satellite power plant could be as high as $1 trillion.
Can this even be accomplished by 2016?
John Mankins, president of the Space Power Association, wonders.
"There are no fundamental 'showstoppers, no breakthroughs in physics required. The key questions concern timing and economic viability," he said. "Solar power satellites will be enormous machines in space _ far larger than any system ever launched _ and it will take time and money to set in place the industrial capacity to realize them. Building solar power satellites that make money _ that are economically viable _ will require the right combination of system designs, component technologies, manufacturing and engineering. These combinations don't exist today. They almost certainly could exist in 10 years or more _ with the right decisions and investments; they almost certainly could not exist in five years or less, even with enormous amounts of money."
And there are the detractors who don't see it happening the way others do. Darel Preble, a Georgia Tech University physicist and chairman of the Space Solar Power Workshop, is an SBSP advocate who remains unconvinced by the Solaren model.
"[It's] highly unlikely they can overcome [technical and fundraising] difficulties in the time frame they are committed to, using their stated, patented satellite-design features," he said.
His main concerns: that the necessary microwave beaming technology has not been developed, thus entailing risky and expensive research; billions of dollars in funding will be hard to raise; and it will be difficult to get regulatory approval from the Federal Communications Commission and the International Telegraph Union.
Renewable energy analyst and investor Chris Nelder dismissed Solaren's project as "pure fantasy" in a blog post last year and said his views have not changed since.
Existing solar plants could "use current, commercially available technology [to run] 24 hours a day" by storing the heat from sunlight, and generate power for as low as 0.3 percent of the price [of SBSP]," Nelder said.
Nelder and Ali both said out that PG&E has taken on no risks; they consider the agreement a public-relations maneuver to show that the utility is attempting to meet its mandate to use renewable energy.
The debate is likely to rage on.
There are no comments yet, be the first!