Space Solar Power by 2016?
As far as alternative energy sources go, solar power has always been the 800 pound gorilla. It seems a no-brainer — a free and virtually limitless source of power for any clever enough to harness it. Unfortunately, factors such as the day/night cycle and the filtering effect of Earth’s atmosphere have conspired to make solar power somewhat inconvenient and inefficient.
In 1968, Dr. Peter Glaser proposed a solution to both of these shortcomings. His idea was to put a massive array of city-sized solar cells into high geosynchronous orbit. Undeterred by nightfall, clouds, seasons, or atmospheric interference, these satellites would collect and convert the sun’s energy into an electromagnetic microwave beam. This beam would be transmitted to large receiving antennas on the Earth, where it would be converted to electricity and distributed on the national electric power grid.
It sounds like the stuff of science fiction, which is of course how most folks regarded it at the time. But when the 1970s rolled around and people began bandying about the words “energy” and “crisis” with alarming regularity, the Department of Energy and NASA began seriously examining the prospect of solar power satellite (SPS).
Eventually, the project was scrapped due to the prohibitive costs. Implementing the SPS system as envisioned would have cost three trillion dollars, which was roughly the size of our gross national product. Proponents of SPS tried to keep the project alive by offering up cost-effective alternatives (such as building the massive cells in a factory on the moon to save fuel and shipping costs). But despite this outside-the-box thinking, the SPS project was relegated to the back burner for the next two decades.
In the mid 1990s, NASA began conducting what it dubbed a “fresh look” study of SPS technology. They revisited a number of the ideas proposed by Dr. Glaser and his peers to determine the feasibility and risks of space solar power (SSP). In 1999, NASA’s Space Solar Power Exploratory Research and Technology program (SERT) came to the conclusion that advances in technology had made space solar power a viable solution to the increasing global energy demand. John C. Mankins, manager of NASA’s Advanced Projects Office, wrote:
Based on the recently-completed “fresh look” study, space solar power concepts may be ready to reenter the discussion. Certainly, solar power satellites should no longer be envisioned as requiring unimaginably large initial investments in fixed infrastructure before the emplacement of productive power plants can begin. Moreover, space solar power systems appear to possess many significant environmental advantages when compared to alternative approaches to meeting increasing terrestrial demands for energy – including requiring considerably less land area than terrestrially-based solar power systems.
The economic viability of such systems depends, of course, on many factors and the successful development of various new technologies – not least of which is the availability of exceptionally low cost access to space. However, the same can be said of many other advanced power technologies options. Space solar power may well emerge as a serious candidate among the options for meeting the energy demands of the 21st century.
And now it looks as if we’re getting close to realizing Dr. Glaser’s vision, albeit on a slightly smaller scale. Just last week, Pacific Gas and Electric (PG&E) announced that they had entered into a contract with the California company SolarEn Corp. Using existing technology, SolarEn Corp plans to launch its satellites into a geosynchronous orbit above the Earth’s equator. These satellites will collect the sun’s energy, convert it to radio waves, and beam it back to a receiving station in Fresno County, where it will be distributed through PG&E’s power grid. If all goes according to plan, PG&E hopes to start providing this power to 250,000 homes as early as 2016.
The project will have an estimated cost of $2 billion, most of which will go towards developing the base station and launching the satellites. SolarEn CEO Gary Spirnak, who previously worked as an engineer for the U.S. Air Force and Boeing Satellite Systems, is confident his company will be able to meet the 2016 deadline. He projects the system, once completed, will be able to generate up to 4.8 gigawatts of power at a price competitive with other forms of renewable energy.
Naturally, there are some environmental concerns about space solar power. Environmentalists are concerned about the effects of radiation from the radio waves. SSP proponents insist that the radio waves will be spread over a wide area, making them harmless to plants, animals, and humans. SolarEn must gain approval from California’s Public Utilities Commission and obtain all of the necessary permits from local, state, and federal agencies before proceeding. It will fall on their shoulders to prove that their technology satisfies all applicable safety standards.
So there is still considerable work to be done before space solar power becomes a reality. But as our energy demands continue to increase globally, the prospect of cheap, clean, and renewable energy is certainly an exciting one.