Solar farms are becoming quite a familiar sign all over the world. However, China is taking it to a whole new level with its announcement of placing a solar power station in orbit by 2050. This would allow China to become the first country that will be harnessing the sun’s energy in space and sending to Earth. What prompted this? The fact that the sun is always shining in space!
Ali Hajimiri, a professor of electrical engineering at the California Institute of Technology and director of the university’s Space Solar Power Project, said, ‘You don’t have to deal with the day and night cycle, and you don’t have to deal with clouds or seasons, so you end up having eight to nine times more power available to you.’
The project will be difficult and quite costly owing to the development of the hardware that is required for capturing and then transmitting the solar power. Furthermore, the launching of the system into space is going to be a feat in itself. China is currently constructing a test facility in the southwestern city of Chongqing for finding out about the most feasible way of transmitting solar power from the orbit to the ground.
The idea of using space-based solar energy as a steady source for renewable power is not new. It surfaces in the 1970s but owing to the complexity of the technology; it was dropped quickly. John Mankins, a physicist who spearheaded NASA’s efforts in the field back in the 1990s, said, ‘We’re seeing a bit of a resurgence now, and it’s probably because the ability to make this happen is there, thanks to new technologies. If you look at the next 50 years, the demand for energy is stupendous. If you can harvest sunlight up where the sun is always shining and deliver it with essentially no interruptions to Earth — and you can do all that at an affordable price — you win.’
The details of China’s plans have yet not been disclosed. Mankins says that a possible way of doing this is by launching tens of thousands of ‘solar satellites’ that could then link up and become a cone-shaped system that orbits at the height of about 22,000 miles. The satellites would feature photovoltaic panels that will carry out the conversion of sunlight into electricity. It would then be converted into microwaves and sent to ground-based receivers. Mankins says that such a solar facility is capable of generating a constant flow of 2,000 gigawatts power.
According to Terry Gdoutos, a Caltech scientist working in collaboration with Hajimiri on the space-based solar research, ‘State-of-the-art photovoltaics are now maybe 30 percent efficient. The biggest challenge is bringing the mass down without sacrificing efficiency.’ Mankins estimates that his vision of solar satellites might cost around $10 billion per unit. He says, ‘Ground-based solar is a wonderful thing, and we’ll always have ground-based solar. For a lot of locations, rooftop solar is fabulous, but a lot of the world is not like Arizona. Millions of people live where large, ground-based solar arrays are not economical.’
