How to find and access energy needed to keep Earthly civilization going and growing is an old problem. But the solution to that problem may not be on the Earth.
Modern, industrial civilization has provided a lifestyle for
ordinary people that Kings and Emperors in previous eras would have envied. The
growth of technology has provided appliances that do the work for each person
that previously was done by dozens of servants. People have access to mobility,
comfort, entertainment, and information undreamed of just a short time ago in
human history.
The problem is that all of those vacuum cleaners, plasma
TVs, home computers, and automobiles need energy to make them work. The advance
of technology means more devices needing more energy. The growth of population
means more people demanding those devices needing more energy. And, to top
everything off, regions of the world emerging from third world status—India
and China being
prime examples—create an even greater demand for energy.
Nearly every source of energy on Earth presents problems.
The burning of oil and coal causes pollution, including the sort that some
point to as the cause of global warming. Potential new sources of oil tend to
be in places that are either politically unstable, such as the Middle
East, or in environmentally controversial areas, such as Alaska
or off shore from California or Florida.
Nuclear power, while safer than in previous years, is still politically
controversial and still produces radioactive waste that is difficult to dispose
of. Renewable sources, such as ground based solar and wind, cannot generate
enough energy to keep pace with the growing demands of human civilization.
Is the world condemned to a Hobson’s choice of rationing
energy or else accepting the dangers and tradeoffs of exploiting more and more
of the Earth’s energy sources? Perhaps not. The answer may well lay about a
quarter of a million miles away, at a place people can see on most clear
nights. Indeed, the Earth’s Moon may be the Persian Gulf
of the later 21st Century, if we have the will to make use of what
it has to offer.
Helium 3 Fusion
Over billions of years, solar wind has deposited an isotope
called Helium 3 onto the lunar surface. Helium 3 is not found in nature on the
Earth, though trace amounts have been produced in nuclear experiments. Helium
3, however, may be the fuel which powers the future, when fusion power become
practicable
While the promise of fusion energy remains elusive, it has
the potential of unlocking a source of power that could sustain civilization
for thousands of years. One problem is that some forms of fusion, using
deuterium and tritium (isotopes of hydrogen) release eighty percent of its energy
in the form of radioactive neutrons, greatly increasing cost and safety issues
for any potential commercial application.
Fusion using helium 3, on the other hand, produces little or
no radioactive byproducts. The closest place where helium 3 can be found in any
quantity is the surface of the Moon, where it is estimated a million tons of
the isotope exists, depositing over billions of years by solar wind. Helium 3
could be mined from the Moon and delivered to Earth where just a few tons of
the isotope could supply all the power needs of the United
States for a year, without pollution
Research into technology to not only develop fusion power
plants using helium 3 as fuel, but to also mine helium 3 from the lunar surface
is currently being conducted by the Fusion Technology Institute at the
University of Wisconsin at Madison. At the current pace of research, helium 3
fusion power is still decades away, though scientists suggest that time might
be greatly shortened given more resources and attention.
Space Based Solar Power
Dr. David Criswell at the University
of Houston at Clear
Lake thinks he has a better idea.
Why mess around with developing the technology to build fusion power plants,
when there is already a fusion power plant readily available? That fusion power
plant is called the Sun. The problem is how to tap into the energy it produces.
Space solar power is an old concept, first developed by
Peter Glasser at Arthur Little in the late 1960s. The idea is that huge solar
collectors, located in orbit around the Earth or on the lunar surface, would
collect the flood of energy flowing from the Sun and beam it to the Earth via
microwaves. On Earth, the microwaves would be converted to electricity and fed
into the power grid. Space based solar
energy is also seen as a means of powering space based industries and mining
operations.
In the early seventies, Dr. Gerard O’Neill of Princeton
suggested that the cost of building these “powersats” could be decreased by
using off world resources, from the Moon or from Earth approaching asteroids,
to build them. A more recent study, conducted by the National Research Council,
suggest that advances in solar cell efficiency, robotics, composite materials,
and digital control systems, as well as successful tests of wireless
transmission technologies make space solar power even more feasible.
Dr. Criswell believes that he has a more elegant idea.
Instead of building huge powersats in high Earth orbit at great expense, why
not build solar collectors on the lunar surface? Criswell envisioned robot
miners/factories traveling the lunar surface, mining it for silicon, and
creating solar cells and laying them out on the Moon for a fraction of the cost
of building space based powersats. Power would be beamed to Earth, via small,
relay stations in orbit.
The advantage over Helium 3 fusion is that the technology to
build this greatest of all power grids exists today. Criswell estimates that
the lunar surface captures 13 trillion terawatts of energy from the sun.
Capturing even one percent of this energy would provide prosperity for ten
billion people on the Earth.
The Moon and the Hydrogen Economy
A third way the Moon, as well as other celestial bodies such
as Earth approaching asteroids, could be the source of a solution to Earth’s
energy problems was described in a recent book, Moon Rush, written by aerospace engineer Dennis Wingo. Wingo makes
the case that billions of years of impacts by nickel-iron asteroids have
deposited large quantities of platinum group metals on the Moon. The reason
this fact is important is that these kinds of metals are a critical component
in hydrogen fuel cells.
Fuel cells have the potential to provide power for
everything from automobiles to office buildings and small factories, with the
only byproduct being water vapor. In order to create this chemical reaction,
platinum is needed as a catalyst.
In his book, Wingo suggests that there are not enough
reserves of platinum group metals on the Earth to support a hydrogen economy
run by fuel cells. Also the refining of platinum group metals on Earth
generates a considerable amount of toxic waste. Wingo suggests that platinum
group metals mined and refined on the Moon, or Earth approaching asteroids,
could make up the difference and jump start a hydrogen economy on Earth.
The Future
As the United States
and other countries contemplate sending people back to the Moon for the first
time in decades, a debate has arisen over whether it is worth the cost. Science
and exploration are certainly important things, but if the Moon is the source
of the solution to Earth’s energy problem, then going back to the Moon might be
worth any cost. Just as earlier explorers set forth across trackless oceans for
“God, glory, and gold”, future explorers may set forth on an even more
trackless, airless ocean for “Energy, commerce, and science.” It is a bright
future, filled with the potential of prosperity and high adventure.