Another very interesting way of harnessing the Sun’s energy is Space-based solar power or SBSP. Like it sounds, the process involves collecting solar energy in space. SBSP isn’t too different from collecting solar energy on Earth in that they both make use of solar panels. Only this time the solar panels are designed to orbit the Earth as a satellite and beam energy down via microwaves or lasers.
Harvesting solar energy in space is much more efficient than on the Earth. A solar satellite would have the ability to direct power to locations on the Earth that need it the most. Weather, climate, and the magnetic field all reduce the capacities of Earth-based solar power collection and are almost non-existent in space. Space-based solar panels can also harvest solar energy 24 hours a day, whereas Earth-based solar panels can only collect for 12 hours at most. Technically, it’s possible to harvest solar energy on Earth at its poles for 24 hours a day but it is very inconsistent and can only be done for only six months out of the year.
You’d think that with such promising potential, the use of space-based solar power would be further on its way already. However, has had its own share of problems. The most prominent being how the solar energy collected by the satellites can be transmitted back to Earth. Using wires that extend from the Earth to an orbiting satellite is both impractical and impossible. Many wireless power transmission systems have been proposed but these are still under development and not yet being used.
Wireless Energy Transmission
Wireless energy transmission as an alternative to wired power distribution (our current system of electrical power distribution) was first developed and demonstrated by Nikola Tesla. In 1899, Tesla demonstrated wireless power transmission by powering a field of fluorescent lamps located twenty-five miles from their power source without using wires. Tesla’s work was beyond impressive, but at that time it was cheaper to use copper wire rather than produce the kind of power generators that Tesla’s methods required.
Since 2008, the Japanese Space Agency (JAXA) has been working to develop wireless energy transmission technologies. Their goal is to be able to transmit energy from orbiting solar panels by 2030. On March 12th, 2015 Mitsubishi Heavy Industries, Ltd. (MHI) successfully conducted their first ground demonstration test of wireless power transmission.
In their test, 10 kilowatts of electrical power was transmitted by a microwave unit and confirmed at a receiver unit 500 meters away. Using part of the transmitted power, LED lights placed on the receiver confirmed the successful transmission. This marked a new milestone in the distance and amount of power that could be transmitted. As a reference, 10kw is enough to power a few conventional kitchen appliances. These test results are very promising for future applications like SBSP as well as more commonplace things like phone charging and powering everyday appliances. Potentially, the need for traditional wires and cables will become obsolete.