Japan’s space agency, JAXA, has been making efforts for years to enable solar power transmission from space. In 2015, the agency successfully transferred 1.8 kilowatts of power—enough to power an electric water heater—to a wireless receiver over a distance of more than 50 meters. And now Japan is in pursuit of developing this technology.
A Japanese public-private partnership aims to achieve solar power transmission from space as early as 2025. The project, led by a Kyoto University professor who has been working on space-based solar energy since 2009, plans to put a series of small satellites into orbit. These satellites will try to transmit the solar energy they collect to ground-based receiving stations hundreds of kilometers away.
The idea of using solar panels and microwaves in orbit to send energy to Earth was first proposed in 1968. Since then, a few countries, such as China and the USA, have spent a lot of time and financial resources on the idea.
What makes the technology attractive is that orbital solar arrays represent a potentially unlimited source of renewable energy. In space, solar panels can collect energy at any time of the day, and clouds are no problem since they transmit the power they produce using microwaves. But even if Japan successfully deploys a set of orbital solar arrays, the technology looks close to science fiction for now. Because it costs about 7 billion dollars to produce a series that can produce 1 gigawatt of energy with current technologies. This amount of energy is close to the output power of a nuclear reactor.
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