[Catalyst 2017]

PILOT
SIGNAL
CONVERTER
MICROWAVE
BEAM
DC CURRENT
RECTIFYING
ANTENNAES
AC
CURRENT
its lack of fossil fuel resources and the 2011
incident at the Fukushima Daiichi nuclear
plant, Japan, in desperate need of alternative
energy sources, has proposed a 25-year
technological roadmap to the development
of a one-gigawatt SSPS station. To accomplish
this incredible feat, Japan plans on deploying
a 10,000 metric ton solar collector that would
reside in geostationary orbit around Earth.6
Surprisingly, the difficult aspect is not building
and launching the giant solar collector; it’s the
technical challenge of transmitting the energy
back to earth both accurately and efficiently.
This is where JAXA has focused its research.
Historically, wireless power transmission has
been accomplished via laser or microwave
transmissions. Laser and microwave radiation
are similar in many ways, but when it
comes down to which one to use for SBSP,
microwaves are a clear winner. Microwaves
have longer wavelengths (usually lying between
five and ten centimeters) than those of lasers
(which often are around one micrometer), and
are thus better able to penetrate Earth’s
atmosphere. 6 Accordingly, JAXA has focused
on optimizing powerful and accurate
microwave generation. JAXA has developed
kW-class high-power microwave power
transmission using phased, synchronized,
power-transmitting antenna panels. Due
to current limitations on communication
technologies, JAXA has also developed
advanced retrodirective systems, which
allow high-accuracy beam pointing. 7 In
2015, JAXA was able to deliver 1.8 kilowatts
LARGE SCALE WIRELESS TRANSMISSION
IS A REALISTIC OPTION TO POWER
ELECTRIC CARS, TRANSMISSION TOWERS,
AND EVEN SATELLITES.
accurately to a rectenna 55 meters away
which, according to JAXA, is the first time
that so much power has been transmitted
with any appreciable precision . Although
this may seem insignificant compared to
the 36,000 km transmissions required
for a satellite in geosynchronous orbit,
this is huge achievement for mankind. It
demonstrates that large scale wireless
transmission is a realistic option to power
electric cars, transmission towers, and even
satellites. JAXA,continuing on its roadmap,
plans to conduct the first microwave
power transmission in space by 2018.
Although the challenges ahead for
space based solar power generation are
enormous in both economic and technical
terms, the results could be revolutionary.
In a manner similar to the introduction of
coal and oil, practical SBSP systems would
completely alter human civilization. With
continuous green energy generation, SBSP
systems could solve our energy conflicts
and allow progression to next phase of
civilization. If everything goes well, air
pollution and oil spills may merely be
bygones.
WORKS CITED
[1] Sasaki, S. IEEE Spec. 2014, 51, 46-51.
[2] EIA (U.S. Energy Information Administration).
www.eia.gov/electricity/monthly (accessed Oct. 29,
2016).
[3] Wolfgang, S. Acta Astro. 2004, 55, 389-399.
[4] Yang, Y. et al. Acta Astro. 2016, 121, 51-58.
[5] Wang, R. et al. IEEE Trans. Micro. Theo. Tech.
2014, 62, 1080-1089.
[6] Summerer, L. et al. Concepts for wireless energy
transmission via laser. Europeans Space Agency
(ESA)-Advanced Concepts Team [Online], 2009.
https://www.researchgate.net/profile/Leopold_
Summerer/ (accessed Oct. 29, 2016).
[7] Japan Space Exploration Agency. Research on
Microwave Wireless Power Transmission Technology.
http://www.ard.jaxa.jp/eng/research/ssps/hmimssps.html
(accessed Oct. 29, 2016).
DESIGN BY Brianna Garcia
EDITED BY Aseem Utrankar
CATALYST | 31