Aboard an imaginary space station surrounded by distant planets, an astronaut on the fringes of human life toiled to turn the sun’s rays into electricity and then zapped it through space and back to the planets to be used as a power source.
“Our beams feed these worlds energy drawn from one of those huge incandescent globes that happens to be near us. We call that globe the Sun,” the spaceman says in one of Isaac Asimov’s earliest works, the 1941 science fiction short story “Reason.”
What was then an implausible idea—collecting solar energy in space and sending it to Earth—is now the goal of scientists around the world, marking a new space race that could end reliance on dwindling fossil fuels, fundamentally shift power in the geopolitical conflicts they have sparked, and meet the rising demand for energy from the developing world.
Paul Jaffe, a spacecraft engineer and principal investigator at the U.S. Naval Research Laboratory in Washington, D.C., has brought the U.S. closer to that goal with his work on space solar technology, which has drawn international attention—and for good reason: The innovation would have a profound impact on humanity.
“In countries right now where they’re trying to deal with poverty, water scarcity, poor health, lack of education, and political instability—these are all things you need energy in order to fight,” Jaffe told TakePart.
About 1.2 billion people have no access to electricity, and another 1 billion do not have reliable electricity networks needed for powering medical equipment, safely storing blood and vaccines, performing emergency health procedures after dark, and other uses, according to a United Nations Foundation report. Smoke from polluting and inefficient cooking, lighting, and heating devices kills an estimated 4 million people a year and can cause chronic illnesses, the report said. What’s more, energy consumption worldwide is projected to grow by 48 percent between 2012 and 2040, with most of the growth in developing countries, according to the U.S. Energy Information Administration. That could spell a climate change disaster if clean, reliable energy doesn’t reach massive populations in India and China, where energy production has relied on fossil fuels.
“[Solar power satellites] introduce the profound capability to send clean, constant energy nearly anywhere in the world, which would be huge for places that don’t currently have reliable electricity,” Jaffe said. “In Western civilization, we expend an enormous amount of energy per capita, which is not matched in the developing world, and if it does get matched in the developing world, that’s going to represent a huge, huge demand for new energy.”
Jaffe estimates it would cost tens to hundreds of millions of dollars for a demonstration and billions of dollars for an operational system. But he says that ongoing breakthroughs in technology, some achieved at the Naval Research Lab, can help harness space solar power for use on Earth. Jaffe and other space solar experts believe it can be done within the next decade.
The plan got a major boost at a State Department contest in March, where, in a room of high-ranking government officials, Jaffe proposed solar power satellites that would capture sunlight in space, convert it to microwave energy (a form of electromagnetic radiation), and then wirelessly transmit it to rectennae (antennae that can convert the energy to electricity) on Earth. Backed by recent technological advances and nearly a decade of research, which began in 2007, the proposal beat 500 entries to win four of seven categories: innovation, collaboration, presentation, and—importantly, considering the crowd—the people’s choice award.
“That was a big deal,” said aerospace engineer Feng Hsu, chairman of the National Space Society’s Space Solar Power Committee and former NASA space flight risk expert. “Space solar power really caught the interest of the Pentagon leadership, [as] it can minimize confrontation between nations and solve geopolitical conflicts because energy is a big issue.”
The advances come amid concerns about diminishing coal, oil, and natural gas burned for energy, a practice that produces carbon dioxide emissions blamed for climate change.
“There will come some point where all of the fossil fuels that took millions of years to be stored will be depleted,” Jaffe said, “and at that point, we should have another [energy] source to turn to.”
Of course, solar power can be captured without leaving Earth’s surface—as evidenced by an increasing number of homeowners that install solar panels on their roofs as they grow cheaper and improve. But there are advantages in seamlessly transmitting it where it is needed. It’s true that terrestrial solar panels are easier to update than space satellites and are becoming cheaper, Jaffe said. But on Earth, panels can be unusable during long periods of cloudy days and require energy storage—and such batteries are limited, inefficient and expensive.
Although many solar panels are on the grid, “there is currently no large-scale effective and economical means for storing utility-scale levels of power,” Jaffe said.
A solar power satellite in space would provide continuous power to people on Earth because it would have endless access to sunlight—without interferences from clouds, the atmosphere, or night—and would not need storage, Jaffe said.
“Having continuous power similar to what you have from a coal or a nuclear plant is a big deal,” he said. “The shortcoming of wind and solar is that they are intermittent, leaving the balance of energy needed when they are unavailable to fall on coal, natural gas, nuclear, and other nonrenewable baseload sources. Space solar is clean and constant, allowing it to serve as a baseload source.”
Unlike terrestrial solar power, space solar energy could be transmitted globally and sent on demand to areas struck by natural disasters or to remote military posts, where it’s often difficult and dangerous to bring fuel.
“There’s no other energy source known that could switch from one part of the planet to another part so quickly,” said space entrepreneur and former NASA executive John C. Mankins, whose solar power satellite design, SPS-Alpha, appears in his 2014 book, The Case for Space Solar Power. “It could move the delivery of power in literally a second from San Francisco to Chicago. Next week it could send that same energy to South America.”
Animated demonstration of John Mankins' SPS-Alpha satellite design. (Video: YouTube)
How would that happen?
All elements of the technology for sending power from space to Earth have been tested in some form, Jaffe said. Communications satellites already send small amounts of sunlight-generated wireless power to the planet every day.
Perched about 22,000 miles above the Earth's surface, in an orbit where sunlight is brighter than anywhere on the planet, solar power satellites would zap power to inexpensive mesh-like receivers placed above the ground on 20- to 50-foot poles, leaving the land or water underneath for farming, raising livestock, or other uses, Mankins said.
Could beaming energy from space pose risks?
“If you did it wrong, the answer is absolutely yes,” said Mankins, noting that sending “wildly unsafe” high-energy lasers instead of microwaves to Earth could cause problems like damage to eye retinas. “If you do it right, it could be safer than wind power.”
“People are often concerned about frying birds with the wireless power transmission,” Jaffe said, “but the system would operate within accepted safety limits by design.”
The energy would stream from thousands of satellites needed to supply power to the world.
“These platforms, once they are developed and deployed, will be eternal,” Mankins said. “They’ll be like islands. They’ll recycle, and they’ll continue for centuries.”
Recent technological breakthroughs are lowering the cost to launch solar power satellites into space, Jaffe said, including the development of more-efficient and lightweight solid-state electronics that reduce the weight of cargo carried to space.
Jaffe built two prototypes that convert sunlight to microwave energy, which would be part of a larger set of solar power systems in space. The “sandwich” module has a photovoltaic panel on one side that receives solar energy, electronic wiring in the middle that converts the energy to a radio frequency, and an antenna on the other side that would send the power to receivers on Earth. The “step” module opens the sandwich to absorb more sunlight without overheating. The modules hold world records for conversion efficiency and specific power, which is the amount of power available per unit of mass it took to produce it.
In other words, the devices are light yet powerful and because of their reduced mass, less expensive to send to space—which is crucial to getting them off the ground.
Jaffe was also the first scientist to test a space solar module in a vacuum chamber that mimics some conditions in space, including extreme cold and concentrated sunlight. (Jaffe did not perform zero-gravity testing, which typically requires an aircraft that provides just short periods without gravity and does not simulate other aspects of space.)
The experiments at the Naval Research Laboratory (where GPS technology was also invented) had far-reaching effects. After results were published between 2012 and 2015, Chinese and Japanese researchers began testing parts of their space solar technology in a similar chamber, Jaffe said.
“Our testing the prototypes in a space-like environment was a really important step,” Jaffe said. “Since that time, other researchers in different parts of the world have started to do that as well, and I think that is a critical step to showing that the technology is closer to readiness for actual use in space.”
Jaffe said his prototypes are “a key element” to many of the space solar concepts being examined. Caltech and Northrop Grumman are among the groups seeking to improve on his results. Last year, the pair formed the Space Solar Power Initiative, which seeks to create an ultralight solar energy collector.
Gary Spirnak, CEO of start-up Solaren in Manhattan Beach, California, said his team of scientists is also developing a lightweight solar power satellite that could be tested in space by 2020.
“You have to make it light enough, and I believe we’ve solved that problem,” he said. “We’re in the process right now of proving it.”
Another advancement may affect the space solar power game: the mass production of spacecraft.
“For the most part, satellites have been these very painstakingly, artisanally crafted devices that take years and lots of labor,” Jaffe said. “Now we’re seeing small and large companies mass-produce spacecraft, and this drives the cost of space hardware down.”
The price of transportation to space is also expected to dip because private aerospace companies Blue Origin and SpaceX have both recovered booster rockets for reuse. In the past, the rockets were discarded after one space flight. The ability to launch, land, and reuse a booster rocket would make it cheaper to send satellite components to space over multiple launches, which may not happen for at least another decade.
Jaffe began probing the potential of space solar energy after seeing the concept in a 2007 National Security Space Office report. A team at the Naval Research Lab studied the idea and concluded what so many others had. “We definitely found that it was technically feasible, but the question remained the economics,” he said.
Now that the question is being answered, Jaffe has proposed steps over five years to begin development of a solar power system in space, including tests of a wireless power link on the ground and a demonstration of the system on the International Space Station.
If started now, the development phase could be done by 2021 for about $350 million, Jaffe said. It would end with a pilot system, worth about $10 billion, that could power more than 150,000 homes.
“The longer we put off looking into new and potentially revolutionary sources of energy, the harder it will likely become,” Jaffe said. “It’s important to realize that wind and solar have had decades to evolve and hone themselves to the point where they are truly competitive with fossil sources. Space solar hasn’t had that opportunity yet.”
U.S. scientists are not alone in their quest to develop and deploy solar power satellites. Among the countries investigating them are China, which has heavily researched the concept, and Japan. Jaffe called them “the world leaders right now, with sophisticated long-range wireless power transmission” that will enable the satellites to send energy from space to Earth.
Could the nations work together?
Such an alliance has precedence, Jaffe said, citing the International Space Station and the International Thermonuclear Experimental Reactor, an energy project in France that seeks to build an experimental nuclear fusion reactor to produce carbon-free energy. It involves the U.S., the European Union, Russia, China, India, South Korea, and Japan—“countries that don’t typically cooperate on anything,” he said.
“One of the reasons that ITER enjoys this broad international collaboration is there’s a recognition that if that technology comes to fruition, it has literally revolutionary effects for human civilization,” said Jaffe, whose own team includes Mankins and members of NASA and the Department of Defense. “Space solar is similar, although it has the added benefit of global distribution.”
Solaren has been working on its own solar power satellite since at least 2009, when it signed an agreement with Pacific Gas and Electric in San Francisco to provide it with energy from space by this year. Spirnak said the date has been postponed as he continues to raise funding. In the meantime, he declined to reveal details of Solaren’s design.
“Most of our competitors are countries, not companies,” Spirnak said. “They have infinite resources, so I don’t want to help them. To us, this is business. It’s a competition. We’re here to make money for our investors.”
The stakes are high. “With space solar power, we’re tapping into literally a multi-trillion-dollar market,” he said.
China, Japan, and the United Arab Emirates might be first to send a solar power satellite to space because of their interest and efforts, Jaffe said, “but we would almost certainly see it coming.” China is reportedly planning to build a solar power station in space, while scientists in Japan conducted a successful wireless power demonstration on the ground last year. Also, the UAE, in an apparent bid to stay in the energy business after oil dries up, is doing a space solar financial analysis, with a “course forward” to be announced this summer, said Jaffe, who participated in a technical assessment of space solar in the UAE with other experts on the subject earlier this year.
Yet Jaffe warned that a “Sputnik moment” could occur, referring to the Soviet Union’s 1957 launch of the first artificial satellite to orbit the Earth.
“When Sputnik was launched, it came as a shock to the U.S. and resulted in a lot of investment being put in science and math education and ultimately led to the moon landing and other endeavors that we achieved in space,” he said. “While of course we could always wait for such a time, there’s a lot of benefit [if] we lead rather than [try] to play catch-up later.”