inside ases | chair’s corner
pedal power revisited
By John re YnoLds, FAiA
John Reynolds, FAIA, is
chair of the American
Solar Energy Society
board. Contact him at
this issue’s article, “Let the Solar Revolution Begin”
(page 24), inspires us with high-tech approaches for
energy production. For a lower-tech view, I want to
revisit the human-powered option. In the May/June 2007
issue of SOLAR TODAY, “ 6 Reasons to Use Pedal Power,”
I argued for person-powered transportation. Now consider
human activity as a source of electricity generation.
Hitching a stationary exercise bicycle to a generator is
not a new idea, although it is rare. Many years ago a group of
futurist architects envisioned a community where a multitude of exercise bikes would be used to gradually pull down
a huge inclined spring; the spring represented a battery of
kinetic energy. As electricity was needed, the spring would
return to its upright position, powering a generator as it
released its stored kinetic energy. The spring would constitute a huge sculpture to tell the community just how much
energy its members had stored, at all times.
As Americans become increasingly conscious of the environmental threats from fossil fuel and nuclear electricity
generation, and the personal health threats from sedentary
obesity, some opportunities arise. At last summer’s U.S.
Olympic Team Trials in Eugene, Ore., a supermarket sponsored a tent (see photo) in which spectators could sign up
for timed stints on an exercise bicycle. All the bikes were
connected to a generator and battery system to power lights
and the tent’s signboard, which showed the stored kilowatt-hour total as it increased through exercise and decreased
through electricity use.
A health club in Hong Kong uses the exercise machines
students and faculty at
oregon state university,
ready to feed power
to the grid during the
oregon stAte universit Y
to generate electricity that directly powers the lighting; the
stronger you exert yourself, the brighter the light. What
a way to show off to admirers! Green Microgym clubs in
Portland and Seattle have a Burn and Earn program. For
every hour spent on the energy-generating Team Dynamo,
a spin bike, or on a treadmill, you get $1 added to a card,
redeemable in merchandise at the gym gift shop. No, $1 per
hour is not even close to minimum wage, but of course you
are already paying the gym for the opportunity to keep fit.
The electricity helps power amenities such as satellite radio,
flat-screen LCD high definition televisions, and wireless
Internet. That’s a need for a whole lot of people on exercise machines, but the Portland gym also has photovoltaic
modules on the roof and claims solar electricity offsets of
40 percent. Conservation practices save 55 percent of the
building’s original energy budget. The bottom line: The gym
reduces its grid-energy purchases by 73 percent.
The Dixon Recreation Center at Oregon State University
in Corvallis, Ore., operates 22 elliptical trainers, each used
for eight to 10 hours daily. OSU proposes to equip each
trainer with a ReCardio generator capable of producing up
to 400 watts (the average sweating undergraduate apparently produces about 130 watts). The trainer buss should
produce 3 kilowatts, which will be fed to the utility grid to
displace some of the recreation center’s existing load by at
least 3,500 kilowatt-hours annually. Without this generator,
a trainer turns athlete energy into heat; the heat dissipater
runs as high as 140˚F. That’s quite a load on building cooling, but could help in cold weather.
The Energy Trust of Oregon has agreed to an incentive
of up to $5,812.50 for the trainer demonstration project.
Generator manufacturer ReRev has offered to install the
product at cost and to provide all necessary operations and
maintenance costs free, for five years. Pioneering has its
rewards as well as its risks. To meet Energy Trust’s goals
of a demonstration project, OSU has developed a plan for
disseminating data gathered and information learned from
We may well ask why an inverter and grid tie is necessary,
because this building will always use far more electricity
than these exercise machines can generate. But whether
used internally or passed to the grid, it seems reasonable to
make high-grade electricity rather than just low-grade heat.
As another form of distributed generation, exercise-generat-ed electricity has many of the attributes of photovoltaics.
The best way we can use exercise to save huge
amounts of energy is to walk or ride a bicycle instead
of driving a car. Moving only our body weight plus that
of a bicycle requires vastly less energy, all of it from a
renewable source. Consider the pollution avoided, the personal benefits gained, the money not spent on gasoline.