The Earthlings on the Solar Stage
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This year, the Native Earthlings are off the grid and
fusion-powered with the
The Solar Stage is making a huge splash everywhere we go, and we can go
anywhere with it!
About the Solar Stage
We don't think that it is going too far to state that the Solar Stage
is a new paradigm for performance art. With sustainability a
necessity, and with the costs of fossil fuels rising every day, we all
have a mandate to pursue renewable power sources. The Solar
Stage
provides all the power we need to play all day, while making us
geographically independent from power grids. We can play in
meadows or go to the top of Pike's Peak for a show, and that means we
can take our music to our extended family of fans and friends, wherever
they are.
We have only begun to explore the extraordinary possibilities of
low-power audio gear that still fills a space with music.
Low-power lighting systems such as tunable LEDs and
electroluminescent lights are already a reality, and we expect
that we will eventually be able to run light shows as well as
play music.
What's Behind the Solar Stage?
If you don't already have your own solar stage, now is the time to
build one.
Get in touch with that Lucky ol' Sun and get yourself rockin'
in
places you never thought you could go. For you
tool-handy
types, here's a look
inside the guts of the Solar Stage. As you can see, this is
not rocket science; it is all built from off-the-shelf parts.
All
you need is some patience and a solar supplier that you can trust.
Let's see how it's done:
1. The Trailer
The trailer doubles as a base for the solar panels and electronics, and
a place to carry our equipment to gigs.
Crow is the proud Papa in this picture.
2. The Solar Panels
The Solar Stage collects sunlight via two photovoltaic panels.
Each SunWize SW115 panel outputs 115 watts of power, for a
total
of 230
watts.
The panels provide direct current at 16.7 volts.
You'll
notice that SunWize Technologies, like most manufacturers, cherry picks
their PV cells and offers two versions of what is essentially the same
panel. One has slightly more efficient cells and costs more
because of that. A panel like this has a "rated" working life
of
about 50 years, at which point the cells will still put
out 85% of their design power. We hope to live long enough to
see that.
The Charge Controller and Power Inverter
The solar panels are wired into a charge controller that regulates the
current supplied to the battery. This is the heart of the
Solar
Stage. The charge controller keeps the battery topped up
while
protecting it from being damaged by overcharging. The life of
the
battery is directly impacted by the quality of the charge controller,
so this is not a place to skimp. The Solar Boost 2000E from
Blue
Sky Energy is a pretty good one.
The inverter takes 12 volt direct current from the battery and converts
it into standard 120V alternating current to run our gear. We
have considered running directly off 12V DC, but so far it's been
difficult to find much gear that could do that without major mods to
the power supplies. This inexpensive Whistler PP300AC
inverter
seems to do a pretty good job. It will shut down
automatically if
the battery voltage drops too low, preventing the battery from being
discharged completely.
The Battery
The battery is a sealed lead-acid gel cell battery (Type 8G8D)
with a capacity of 265 Amp-hours at a nominal 12 volts.
This
battery is designed for deep discharge cycles, unlike the battery in
your gas guzzler, which is optimized for that big surge of power you
need when you start it. If you are contempating a solar power
system, you will want to invest in good batteries.
Which brings us to the Real Question:
How long can we play?
Believe it or not, modern sound equipment does not use that much
current unless you are trying to rock a stadium or run a light show.
Our amps, mixer, PA and electronic gear draw less than two
hundred watts. On a sunny day, the solar panels provide all
the
power we can use without ever drawing down the battery. Even
on a
cloudy day , or in the shade, the battery is fully charged again before
we get back from a break. After dark, we are working on
battery
power only. How long can we play after dark?
Battery capacity = 12 volts x 265 amp-hours = 3180
watt-hours.
Assuming we only want to draw the battery down by about 50%,
we can use 1590 watt-hours.
Our usage = 200 watts
Time to play = 1590 watt-hours / 200 watts = 7.95 hours.
And the answer is:
We can play all night long.
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