Solar Power Used to Extend Broadband Internet Access into Remote Areas [UC San Diego]

source: Solarbuzz 2002.11.06 & UCSD

Researchers at the University of California - San Diego recently developed a way to power their
broadband High-Performance Wireless Research and Education Network (HPWREN) in remote
areas of southern California where traditional electricity is not available.

That is, the HPWREN team has designed and established solar-powered stations that allow their
broadband microwave antennas to reach some of the most rural lands in San Diego County.
Thanks to this natural form of electricity, several Native American learning centers now have access
to the high-speed information highway.

How exactly do the HPWREN solar-powered stations work?

Each system consists of four 80-watt solar panels, which measure approximately 57" by 20" by 2";
four independent 94-AH gel cell batteries; a charge controller; and a DC-DC converter. The overall
system is capable of generating a peak power of 320 watts, which is able to continuously power a
device consuming around 32 watts.

This solar-powered system, which can support up to four 2.4 GHz radios, has five days of
back-up power should the panels fail.

"The solar panels are connected to a charge controller that disconnects the panels when there is
not enough electromotive force to charge the batteries. During that time the radios and amplifiers
receive their power solely from the batteries," explains Todd Hansen, who designed the HPWREN
solar-powered stations.

"Once the sun is up, the panels (at times) begin to charge the batteries in an excess of 20
amps," Hansen continues. "Most of this power goes into the batteries, however, a small amount
of power is taken to power the radios and amplifiers. At this point, the panels are powering the
radios and recharging the batteries from the drain of the night before."