by David Geer
Sun Riders Ahoy at the
Solar Cup Races
Five years back, the
Metropolitan Water District
(MWD) of Southern California
opened Diamond Valley Lake
Reservoir, a fresh drinking water
reservoir. To support work at
the water district, clean water
sports for the reservoir, and
green energy and conservation,
the district inaugurated the
Solar Cup, a yearly event where
students learn, plan, build, and
race their own solar powered
“These kids are our future; let’s get
them exploring alternative energy and
see where they can take it,” says Water
District representative, Julie Miller. But,
in addition to the future of the kids,
there is the future of the District with
which to contend. The MWD employs
many baby boomers who will eventually be retiring. “We need these kids to
start thinking about a career in the water
and public service areas,” Miller adds.
Still, the MWD’s interests are
altruistic as the Solar Cup event, which
includes technical workshops, education in practical math, science, physics,
and engineering, and hard work teach-es kids the value of these disciplines
and the enjoyment of related work,
not to mention teamwork. Some kids
come away from these events with a
new career path or even plans for college that had not crossed their minds.
While it’s difficult to measure the
output of such an endeavor, the Solar
Cup has turned C students into college
hopefuls. Some have gone on to college
or a trade school and even returned to
the area seeking an internship or an
apprenticeship at the Water District.
Above all, the program is highly
successful, giving teachers from nearby school districts the chance to excite
kids about their more difficult school
subjects through a fun, hands-on
program like this. It’s difficult when
high school budgets are low to come
up with an activity that the kids will
latch onto and focus on for six months,
notes Miller. “Not only does this teach
them the text book elements like
physics and science, but it also stretch-es them into doing team work and
working under pressure,” she explains.
Starter Stats, Qualifying,
and Technical Stuff
Forty-three teams signed up for
the 2007 Solar Cup. As the race grew
and more boats and teams participated, the MWD enforced qualifying for
safety’s sake. Too many racers means
too many people at risk.
The MWD can disqualify teams
for any of a number of reasons like
motor and wiring malfunctions or an
overweight boat (over 451 lbs.). Using
the wrong gauge of wiring can
cause the wiring to fail because it
can’t handle the electric load for the
duration of the race.
Racers are instructed to use “one
sun” solar output solar panels. One
sun is a measure based on the peak
noon sunlight power intensity in the
middle of summer, per Professor
Gerald K. Herder, engineering technology department chair, California State
Polytechnic University at Pomona,
which supports the Solar Cup.
The teams outfit the boats with
dead man switches, which are cords
attached to the skippers and the boats
to automatically turn the boat off if the
skipper leaves the boat. The boats
use spring-loaded throttles so if the
skipper lets go, the engine must throttle down to zero.
Average Speeds and
While not strictly scientific, a
Two boats racing neck-and-neck.
The far boat shows deadman switch
attached to skipper.
Boat with different solar panel array.
August 2007 53