Vol. 4, No. 5
For decades alarmists have
argued that the world’s current consumption levels of energy are unsustainable,
and that we should abandon the current energy-intensive economic activity
for one less dependent on energy. Those people who argued that cheaper,
abundant supplies of energy would someday become available when current
energy sources, such as fossil fuels, began to run out were dismissed
as technological optimists with their heads in the sand.
The recent announcement of
a key discovery indicates the technological optimists should have been
described as having their heads in the algae, which potentially could
become an important source of energy sometime in the next 20 or 30 years.
The new discovery harnesses
a survival mechanism displayed by algae. Like most plants, algae relies
on photosynthesis to convert sunlight into energy and as a byproduct gives
off carbon dioxide. Algae normally use sulphur to perform photosynthesis,
but when sulphur is unavailable they will consume oxygen directly from
water, which ultimately causes ponds and other water to become stagnant,
killing most plant species.
But not the algae. The algae
have a defense mechanism whereby they can, for a few days, utilize an
alternative metabolic pathway that produces not carbon dioxide, but rather
hydrogen as a byproduct. After a few days the algae must switch back to
normal photosynthesis or die, but they can be switched back and forth
from regular photosynthesis to the hydrogen-producing process repeatedly.
This could be a cheap, environmentally
friendly way of producing large amounts of hydrogen which can power fuel
cells to run everything from automobiles to small generators for houses.
Hydrogen doesn’t produce any pollutants and since it all of the energy
comes from the sun, it is remarkably efficient (some estimates put its
sunlight to energy efficiency at 10 percent or more).
Currently the yields of hydrogen
from this process are rather small, but researchers are confident they
should be able to boost yields by a factor of 10 in the near future. At
that point a small pond could produce enough hydrogen to power 12 cars
a week (and that figure is assuming current efficiency levels of fuel
cells, although fuel cells available by the time this procedure becomes
commercially viable are likely to be far more efficient.)
With recent advancements in
fuel cell technology, discoveries in finding cheaper, better ways to produce
hydrogen, and improvements in making more fuel efficient engines and appliances,
the key to expanding the available amount of energy while simultaneously
making it cheaper and more environmentally friendly is starting to come
into clear focus.
Reference:
Stagnant
ponds become fuel pumps. Damien Carrington, BBC News Online, February
22, 2000.