It was in 1941 that science fiction author and Boston University biochemistry professor Issac Asimov wrote “Reason,” a short story of science fiction which featured a kind of space station that collected solar energy and transmitted it to different planets through the use of microwave beams. Today, the Japan Aerospace Exploration Agency or JAXA has announced a proposal to build a space based solar energy farm.
The space farm would be comprised of platforms called geosynchronous satellites, equipment which has the same orbital period as the planet’s rotation period. The people of JAXA estimate completion of these platforms by 2030 if work begins by 2020.
There’s always a First Time, Even for a JAXA Geosynchronous Satellite
Geosynchronous satellites are able to remain fixed in a permanent position in the sky, even if antennas based on the ground are fixed in a single direction, making these space based solar energy farm of satellites viewable by any ground-based station on earth.
Geosynchronous satellites have long been used as a network for communications; the proposal from the Japanese space agency is the first time that this network is to be used for a purpose other than communication.
How Solar Microwaves Work
The space based solar energy farm would sound less science fiction, though, if its proposed location was on terra firma but out in space? The JAXA platforms would be located on the ground as well, but that is nothing novel since solar farms are already in existence.
The proposal of installing platforms in space is the clincher in this scenario; the solar energy of light collected from the sun’s rays would be beamed down as the earth as microwaves convertible into electricity.
The Catalyst for Going Solar: Fukushima, March 2011
The Japanese space agency initiative comes in the wake of increasing frequency of massive and destructive earthquakes which have threatened to damage Japan’s several nuclear power plants; a situation that would expose their citizens and environment to the deadly effects of radiation.
The tsunami that destroyed such power plants in Fukushima in March 2011 caused the leakage of radioactive waste and became the catalyst to forgo the use and maintenance of nuclear energy resources. A solar energy-based farm, according to JAXA Professor Emeritus Susumu Sasaki, is the best option for a country with scarcity of land as well as natural resources like coal.
The Latest since Peter Glaser’s Satellite
The different models the Japanese space agency scientists have been working on include one that has two mirrors capable of reflecting sunlight onto a satellite topped with photovoltaic (PV) on its two sides to allow continuous energy use for a total of 24 hours. Another model is a one sided satellite with PV on top which will decrease in efficiency when the earth turns away from the sun’s rays.
According to Sasaki, this plan for harnessing solar energy is the most recent since Peter Glaser, an American engineer who pioneered to meet the challenges required in the construction, launch and operation of geosynchronous satellites, delved into generating, transmitting, and managing power through wireless technology 46 years ago in 1968.
The 80% Efficiency of Microwave Beams
The JAXA scientists will conduct research on wireless transmission of solar energy since long distances are difficult to cover when transmitting power. For the resulting space based solar energy farm to be operable, microwave or laser beams would have to be developed since their wavelengths are shorter and easier to be transmitted and received by small components in satellites.
Because the atmosphere is liable to block short wavelength beams the Japanese space agency is doing extensive on the use of microwave or laser beams which have, more or less, 80% efficiency average to penetrate the atmosphere. Optimism abounds despite obstacles like calculating the satellite’s antenna size and finding the appropriate frequency at which to transmit the microwave beams.
