Space Solar Energy: Transmitting Renewable Energy from Satellites to Earth

Solar energy is the fastest growing form of renewable energy. It currently accounts for 3.6 percent of global electricity production.

According to estimates by energy experts, electricity obtained from the three main methods of renewable energy will increase exponentially in the coming decades: reaching 40 percent by 2035 and up to 45 percent by 2050.

Renewable energy sources should make up 90 percent of the energy market by mid-century, and electricity from solar panels should account for about half of that.

However, solar energy also has many shortcomings, which have been known for a long time. The main thing is that it is not always available. In fact, for example, in our conditions, it is most needed at the time when it is least needed. That is, in the summer, when there are long days with plenty of sunshine.

One of the solutions could be the so-called space solar energy. Because of their position in orbit, the satellites could easily obtain energy from the Sun 24 hours a day, 365 days a year. However, scientists have been grappling with the question of how to send this energy to Earth for decades.

The Space Solar Power Project (SSPP) at Caltech recently completed the first successful wireless power transfer using MAPLE (Microwave Array for Power-transfer Low-orbit Experiment). The main author of the experiment was Professor Ali Hajimiri, whose team was the first to wirelessly transmit energy obtained in space down to Earth.

Cosmic energy directed towards Earth

The project has been planned since 2011, and it went into space at the beginning of this year. The authors themselves call it a success. The device is quite complex and sensitive, so they feared that it might not survive the flight to orbit.

Then the scientists conducted several experiments. In the first of them, they wirelessly transmitted energy in space at a distance of about thirty centimeters. “Our experiments have confirmed that MAPLE can successfully transmit energy to receivers in space,” Hajimiri said. “We also managed to program the system to direct its energy towards Earth.” According to him, the energy sent by the satellite was captured on the roof of the university.