Twelve unorthodox but promising
green technology innovations
The past year has been a bit of a bust for people
concerned about climate change. At a summit in
Copenhagen in December 2009, rich nations in North
America and Europe failed to reach an agreement with
China, India, and other emerging economic powers about
reducing the world’s reliance on fossil fuels such as oil
and coal. Then the United States once again failed to pass
cap-and-trade legislation. But while politicians stumble to
reach a consensus, researchers are pushing forward with
new, if unusual, solutions. From algae farms to wave
energy, here are a dozen ecofriendly but odd ways to
create clean energy. By Ryan Tracy
Painting the world white
Most cities in the world are too black, say some scientists, Roofs are dark, roads
are paved with asphalt, and all that black surface absorbs the sun’s heat. It’s
called the “urban heat island” effect, and it can raise the temperature of a city by
as much as 5 degrees Fahrenheit in the daytime and as much as 22 degrees at
night, compared with the surrounding area. But if pavement were made of more
porous or reflective materials, and if roofs were painted with lighter colors, and if
cities had more shade trees, the city could reflect or block much of that heat,
saving energy by cooling itself. Above, volunteers in New York paint a school roof
with special white paint that will keep the roof cool and reduce the building’s
energy use.
Water-splitting
Most solar cells are limited by a major
constraint: they can’t create electricity
when the sun goes down. But in a
documentary called Cool It set to be
released Nov. 12, Massachusetts Institute
of Technology professor Daniel Nocera
shares a discovery his team made two years
ago. Nocera developed a cheap way to split
water into hydrogen and oxygen using
electricity and a few easy-to-obtain
materials. It’s a breakthrough, he says,
because hydrogen and oxygen can already
be used to create energy in a fuel cell. He
imagines it this way: during the day, a solar
panel on your roof powers your home while
also splitting water stored in the basement.
At night, a fuel cell uses the “split” water
(hydrogen and oxygen atoms) to power the
house until the sun rises. Nocera hasn’t
perfected the system, but already, it’s
considered a giant leap for clean energy.
Algae Fuel
Like all plants, algae absorbs sunlight and carbon dioxide. But it also produces oil that
can be refined and used as diesel or jet fuel. Its potential has scientists and energy
startups searching for ways to create a genetically modified version that will produce
enough oil to be a profitable cash crop. Algae also has what could be a significant
advantage over other bio-fuels like corn. It can grow on dry land and salty water,
meaning it won’t compete with food-producing farmland. It can grow on dry land
and salty water,
meaning it won’t
compete with foodproducing farmland.
More than 100
companies are
working on a way to
make this work on a
large scale, but most
scientists predict it
will take at least a
decade. Above, an
algae farming pond in
Virginia.
Energy from nuclear waste
Today’s nuclear reactors use the same basic technology that was developed in the
1950s, note researchers at Terra Power, a company trying to bring a new nuclearenergy technology to market. Older reactors need a consistent supply of enriched
uranium fuel, and they spit out nuclear waste. Terra Power’s technology improves on
both those points. Its “traveling wave reactor” (above) needs only a small amount of
enriched fuel to start up,
then it can run for years
on the nuclear waste that
currently gives countries
a headache when they
try to dispose of it.
Wave Energy
Harnessing wave power is not new, but proponents say its potential remains untapped
more than 30 years after Prof. Stephen Salter of the University of Edinburgh invented a
way to turn the power of waves into electricity. His invention, called “the duck,” rolled
back and forth as the waves moved past, creating motion that the other parts of
Salter’s device could capture. Today, researchers from Scotland to Oregon are working
on ways to leverage that idea on a larger scale. In Oregon’s case, the goal is to have
ocean-wave energy
producing 2 megawatts
of power—enough to
power about 800
homes—by 2010, and
500 megawatts of
power by 2025. Above,
a wave-energygeneration device at
the University of
Edinburgh.
Stratospheric aerosol injection
Some researchers have developed ideas for cooling the earth in an effort to counter the
effects of global warming. These fixes are not permanent solutions, but offer a kind of
“planetary methadone” for the world’s fossil-fuel addiction, as Stanford University
climatologist Steven Schneider put it. One cooling idea, illustrated above, would mimic the
impact that volcanic eruptions have on the atmosphere. It stemmed from observing the
aftermath of a major volcanic eruption such as Mount Pinatubo in the Philippines in 1991,
which actually reduced the earth’s temperature, likely by blocking sunlight. Inventors at
Intellectual Ventures, a laboratory led by former Microsoft chief technology officer Nathan
Myhrvold, would re-create the impact by attaching a hose to balloons floating miles above
the earth, then pumping
sulfur dioxide up the hose
and spraying it into the
stratosphere. The dust could
reflect enough sunlight to
provide a temporary reprieve.
Still, some scientists say the
only way to really know if
these technologies will work
on a large scale is to actually
deploy them. That hasn’t
happened yet.
Cloud Brightening
The ship modeled above was born from the knowledge that brighter clouds reflect
more sunlight, and less sunlight absorbed by the ocean could mean a cooler earth.
Salter, the same scientist who designed the “Duck” wave-energy machine, designed
the ship. He imagines fleets of these water vessels harnessing wind power both to
sail and to spray fine particles of seawater into the sky. If the process worked
properly, darker clouds would absorb the smaller droplets and become brighter as a
result. “It’s a way to buy time” as the planet’s climate changes, Salters says in Cool It.
Converting animal waste to fuel
If there’s one thing society has no shortage of, it’s human and animal waste. It’s gross, but
the good news is that there’s energy in sewage sludge. When that sludge is “digested” in
large tanks that allow bacteria to break it down, methane gas is produced, which can be
used to create electricity. One farmer in Pennsylvania powers his entire farm this way.
Other methods also exist for extracting energy from waste, but many cities still find it
cheaper to send the sludge to farmland for fertilizer or to a landfill. Below, a woman in
India sorts through cow-dung cakes, which villages use as an alternative to firewood.
Harnessing body heat
The Matrix envisioned a fictional future in which machines enslaved humans and
used the energy in their bodies to survive. Real-life scientists haven’t taken things
that far, but several scientists have developed ideas for harnessing at least some of
the body’s energy. The key is a small device called a thermocouple, which can
generate voltage by exploiting a difference in temperature say, between your body
and the air. Scientists have found that if a conductive material is placed in between
hot and cold temperatures, electricity can be produced. To harness body heat,
scientists imagine a small devise attached to the body that uses a thermocouple to
generate a small charge,
perhaps enough to power a
cell phone. The Defense
Department is researching
whether body heat could
power futuristic devices
implanted in or attached to
the body, like a vital-signs
monitor for a soldier on the
battlefield.
Tornado energy
Sure, wind turbines produce energy. But
how fast could a wind turbine turn if it
could harness a tornado like the “water
spout” above? That’s the idea behind
proposed power plants like the vortex
engine, which would use heat rising within
a chimney to create an artificial tornado.
The wind would power turbines within the
chimney’s walls and be tied to a base at the
bottom of the shaft. “The vortex cannot
break away from the base station,” says the
Web site of Canadian inventor Louis
Michaud. Good to know.
Foot power
In 2007, two MIT graduate
students pioneered the
piezoelectric floor, which
contracts and expands with
the pressure of a footstep,
then captures the energy
generated when the floor
expands. In a crowded place,
say, a Japanese train station,
footsteps could generate
enough power to make the
process worthwhile. So far,
dance clubs in Europe and
train companies in Japan have
used floors to generate
electricity (above, a panel
demonstrating the technology
in Tokyo). A company called
POWERLeap has also tested
piezoelectric panels in Ann
Arbor, Mich.
Injecting water into the Earth
If humans could harness the heat deep within the earth, it might provide a limitless
source of clean energy. That was the promise of companies, like Seattle’s AltaRock
Energy, which have designed “geothermal” energy systems. AltaRock planned to
pump water deep beneath the ground, through a formation of hot rocks, and up
again to the surface, where equipment would capture its heat and then send the
water back down again to restart the cycle. One key snag: fears that the process
might cause earthquakes, as it did on a minor scale in Sweden in 2006. But even
though Altarock closed
a test site in California
(below) late last year,
the idea of geothermal
energy remains alive
and the Department of
Energy is funding
exploratory projects.