Energy and Nanotechnology

In his stimulating New Yorker article titled "Green Manhattan" (October 18 issue), David Owen quotes from Out of Gas: The End of the Age of Oil, by David Goodstein, professor at the California Institute of Technology -- "Civilization as we know it will come to an end sometime in this century unless we can find a way to live without fossil fuels."

Diamondoid molecular manufacturing may provide a large part of the solution, if it is developed soon enough. This is from the Benefits page on CRN's main website:

The main source of power today is the burning of carbon-containing fuels. This is generally inefficient, frequently non-renewable, and dumps carbon dioxide and other waste products (including radioactive substances from coal) into the atmosphere.

Solar energy would be feasible in most areas of the globe if manufacturing and land were sufficiently cheap and energy storage were sufficiently effective. Solar electricity generation depends on either photovoltaic conversion, or concentrating direct sunlight. The former works, although with reduced efficiency, on cloudy days; the latter can be accomplished without semiconductors. In either case, not much material is required, and mechanical designs can be made simple and fairly easy to maintain.

Sun-tracking designs can benefit from cheap computers and compact actuators. Energy can be stored efficiently for several days in relatively large flywheels built of thin diamond and weighted with water. Smaller energy storage systems can be built with diamond springs, providing a power density similar to chemical fuel storage and much higher than today's batteries. Water electrolysis and recombination provide scalable, storable, transportable energy. However, there is some cost in efficiency and in complexity of technology to deal safely with large-scale hydrogen storage or transportation.

Solar solutions can be implemented on an individual, village, or national scale. The energy of direct sunlight is approximately 1 kW per square meter. Dividing that by 10 to account for nighttime, cloudy days, and system inefficiencies, present-day United States power demands (about 10 kW per person) would require about 100 square meters of collector surface per person. Multiplying this figure by a population of 325 million (estimated by the US Census Bureau for 2020) yields a requirement for approximately 12,500 square miles of area to be covered with solar collectors. This represents 0.35% of total US land surface area. Much of this could be implemented on rooftops, and conceivably even on road surfaces.

So along with the need to develop advanced nanotechnology for humanitarian purposes, medical advances, and environmental remediation, we also must hope it can be done soon enough to prevent the end of "civilization as we know it". Oh, and by the way, we've got to figure out how to manage it in a way that prevents a disastrous arms race, economic upheaval, anarchy, or oppression.

Whew, it looks like we've got our hands full. All of us.

Mike Treder

Comments

[Tom Craver]

10kW/person is just electricity - then there's the energy used in transportation and manufacturing - probably the total is about 30kW equivalent per person.

On the other hand, I would hope that nanotech will allow us to be far more energy efficient - probably by necessity. So 10kW/person probably isn't much of an overestimate.

However, I believe that amount will be divided between energy essential to daily living - provided by roof-top solar collectors - and optional energy consumption for things like personal travel and food and services purchased outside the home.

[Chris Phoenix, CRN]

I think I read a few years ago that the total energy usage per capita in the US is 20 kW.

I would expect that a really efficient technology could let us have today's standard of living for 1 kW, total. Our bodies need about 200 W. Lighting could be done for 100W. Computation is trivial. Medicine shouldn't take much. Of course, this assumes chemically recycled food, and efficient (small, slow) transportation, etc.

To have an exuberant lifestyle with nanotech to play with, one might want 10 kW average, peaking at 100 kW or more for travel.

Of course, it'll be easy to make like Trump and build as big as possible; fly your whole mansion to your vacation spot every weekend, or take frequent vacations at orbital hotels; indulge in high-energy motorsports; etc. I could see each person wanting to use a megawatt or more, which would not fit the planet's energy budget.

If we ever get really cheap solar cells and really cheap manufacturing, we will have to start trading heat pollution credits and worrying about climate change caused by albedo change.

Chris

[Jim Logajan]

I've done the back-of-the-envelope computations on solar power and energy requirements several times now - the trick is finding credible information on actual total power and energy usage. Here's a post I made to Usenet a year ago that contains some really useful links worth bookmarking:

http://groups.google.com/groups?selm=Xns9418D2048AEFAJamesLLugojcom%40129.250.170.85

If the rest of the world were to be brought up to the level of U.S. consumption, the power requirements for the whole world would probably increase by a factor of ~5.

So if all the power needed to drive the entire world's economy had to be derived from solar energy, and came from ~10% efficient solar-to-electric sources, and everyone used energy at the U.S. consumption rate, then I estimate a need for ~800 m^2/person. A square ~28 m (~90 ft) on a side. 5 million square kilometers is starting to push things a bit ecologically speaking, so some steps toward increasing conversion efficiency and reducing power needs would be helpful, but not an absolute requirement.

Um, and while nanotechnology would be very helpful in making solar power the main source of power for earth-bound civilization, it isn't an essential requirement - in my humble opinion.

[Brett Bellmore]

It's worth noting that most of the surface of the earth is covered by ocean, much of which is near abiotic due to lack of trace minerals, and which has an albedo of under 10%. Five million square Km of solar panels could be floated in the Atlantic ocean with next to no effect on planetary ecology or energy ballance, and still leave most of the area uncovered.